Zero faith in science LOL, just look at germ theory + vaccines BUT your Food-forest speaks for itself....healthy, happy & abundant w Life. The veg farm, on the other hand, has constant issues w infestation etc. Last wk I spent 2 days adding Nitrogen Fertilizer to all greenhouse plants. I notice the 🐝🦋🐦s stay on the perimeter of the fields where the Forest & Blackberry bushes are. Enough said
There are good actors and bad actors everywhere, in every field, every niche. Some more than others. And if there is money to be made, the more bad actors come out to swindle and steal. Some areas that are heavily with predators are things like cryptocurrency, medicine, farming, meat/veg, etc. But that doesn't mean we should throw the baby out with the bathwater and label all science as bad. Cryptocurrency is a giant scammer party, but that doesn't mean there aren't critical applications (that are green for the planet) that are being developed. Ethereum, nano, these are great examples of world changing technology living in an ecosystem of thieves and bandits. Sure, when tobacco was being marketed as something all the best athletes use, the science that paid for this wasn't unbiased, and thus was flawed. The meat industry is now doing what the tobacco industry did, and pushing propaganda science. But that ALSO doesn't mean that there isn't accurate unbiased science that is Pro-meat, as well as biased "science" that is anti-meat, funded by groups who hope to sell plant based meats. A big indicator of that is what the anti-meat science uses as it's baseline to compare? Do they use industrial agriculture, which everyone knows is terrible, or Silvopasture and regenerative agriculture? Well, what agenda are they pushing? Etc. The world is rife with scammers and liars and bias and agenda. Where it really gets confusing is that this also doesn't mean that plant based meats isn't potentially an incredibly useful technology, even with the inherent bias!!! What an information maze this is, rife with traps and predators, but sometimes those predators are right! Sometimes they are just predators. That's our crazy world that we have to navigate. Same goes for many topics. I am very pro-vaccine in general, but I'm also not blind to the fact that where there is money to be made, one should question the research, especially when there is a conflict of interest in the funding of a thing, ajd the profit of the same thing. I'm certainly not anti vaxx, but I respect people who are, simply because of how muddy those waters are. I'm not anti climate science, or hate climate deniers, because of the same reason. so instead, in those areas, I try to focus on the unifying facts. For climate science, it's that many resources aren't renewable, such as natural materials, coal oil and gas, and biological ones such as life and diversity. So if we can take actions that remedy those things, but they also help with carbon, then we should do it. For example, taking carbon out of the air is a key factor for climate science, but PUTTING carbon into the soils to build a robust food web of life is CRITICAL for the health of our soil biome. So let's do that. We do that with planting more plants and getting more carbon heavy root exudates into the soil. The only consequence of that action is more trees, cleaner air, cleaner water, more animal habitat. That's my approach to these areas of bias in science. I appreciate the sentiment of not trusting science, but let's not have zero faith in science, let's have a heavy skeptical eye towards bias, because there is a lotbof good science being done, ajd it's critical that it gets done, to fight against the biased science that corporations push in order to support their industry's continuation and growth. It wss tobacco and oil in the mid century, but its evident in many places now. The last thing is that the lack of science in an area MAY ONLY indicate a lack of financial incentive to run the science. And if there is a financial incentive to NOT run the science (such as selling fertilizer to farmers) then any science that tries to debunk that, is going to have armies of propaganda science to fight against. So the lack of evidence for something doesn't always mean anything. Failure to prove something isn't proof of failure... especially if the journey to do so isn't even taken. I'm going to pin this comment. I know I went off on a massive tangent here, but the whole discussion is directly centered on the heart of this video... which is to seek information, but also understand that the waters are murky at times, and money muddies all things.
@@CanadianPermacultureLegacy Well said! I used to be really into science as a kid and still am infinitely curious about how things work. But lately I have been more and more skeptical of mainstream science once I started to follow the money trail. There is good work being done but it is often muddied by massive financial backing by those to stand to gain from a particular outcome. This leads to cherry picking data and spinning of the results by so called "experts". The great thing about gardening is it's not that hard to do our own backyard science. Now it may not be super clinical and we may be introducing our own biases but at least we can see the results for ourselves and come to our own conclusions. Stay curious!
@@CanadianPermacultureLegacy this is the approach I like to try and take with these things as well. Sometimes digging through the bias is exhausting though lol
Grad student studying rhizobia (the bacteria in root nodules) here with some clarifications! Root nodules are not really nitrogen storage organs, instead they just act as the housing unit for the bacteria. Rhizobia while in nodules are basically factories. Their existence is devoted to converting N2 to NH3, and this produces a lot of bioavailable nitrogen… but the plant also needs a lot of nitrogen and nitrogen is a very common limiting nutrient in soils. Nitrogen is needed to produce essentially all biomass because there’s a nitrogen in every amino acid which makes up every protein, which makes up every cell in every plant. This nitrogen demand, means that there isn’t really any nitrogen storages, it’s all just constantly being used to produce more plant. So even if the nodules did dissociate from the roots, it’s just releasing a little plant tissue and a bunch of rhizobia (not a bad thing, just not like a nitrogen tsunami washing over the surrounding soils). What I’m trying to say is that all parts of the plant are mostly equal if in terms of nitrogen density, so chopping and dropping leaves would be reasonably similar to chopping the same amount of roots and mulching with that (just looking at nitrogen anyway). All that being said. N-fixers take tons of N from the air instead of from the soil. So they are introducing new Nitrogen to your system at the end of the day. That nitrogen gets sequestered into the roots, leaves, and dead biomass of your system. IDK anything about Taproots lol. TLDR: Leaves/stems have PLENTY of nitrogen, and those leaves were made from nitrogen that was newly added to your system thanks to the ability of N-fixers who use nitrogen from the air instead of the soil. Great video, love the transparency and thanks for all you do!
It looks like permaculture books focus too much on the nodules themselves. I think the overall strategy in the video remains solid though. N fixers mostly provide for themselves. When we just leave them be, they drop leaves, and a lot of that N came from the air. If we chop them, then drop the chopped material, a lot of that N came from the air. At the same time, if the roots die back (seems still to be contentious if they just shrink, or get disassociated), but none the less, even if the nodules themselves aren't a slow release fertilizer pellet, it's still organic material high in N, a lot of which cake from the air. Is that your understanding of it? Anything I have wrong there? I want to make sure my mental model is correct, because I never formally studied this stuff in university. I appreciate your comment so much!
Exactly, nodules aren’t slow release N fertilizer granules, but they are still rich in N (as is the rest of the plant). Another note: rhizobia and N-fixing plants only form that symbiosis when the plant is limited by nitrogen… this means if a n-fixer is happy and healthy in in a N-rich patch of soil, it will not recruit rhizobia to form nodules and fix nitrogen. This means that N-fixers are much more valuable to a nitrogen poor system like a corn field than a lush established climax forest ecosystem. Thanks for responding - your community engagement is top notch!
That last part is very interesting, ajd I've noticed it a lot. I've been digging up a lot of my wilder varieties of seabuckthorn, and I'm noting a huge disparity in nitrogen nodules. Sides of hills and more neglected areas have much more nodules on the roots than areas in my main strip where I tend to focus more attention, more chop and drop, more mulch top upside, and more yellow gold applications around fruit trees. It makes sense and echoes what I'm seeing here. Thanks so much for the comments. I love learning things from you all. Everyone is an expert in something and can teach you something. ❤️
"When I read something and realize I've been parroting something that may have no scientific backing, I think it's my due diligence to respond back to you guys..." God bless you for this! Too many people let pride get in the way of truth. If everyone was so willing to jettison unsupported beliefs, what a better world we could make!
A core problem with "there's no scientific evidence" as an argument is that any such research is only done if a researcher can get funding and the vast majority of funding is tied to someone making money from the results.
This is 100% true. Failure to provide proof, isn't proof of failure. Especially when there isn't even an attempt to do so, because there is no financial reason to. And even worse, where there IS a financial reason to maintain the status quo.
A place to look would be old Soviet records. Don't get me wrong, the Soviet Union was awful for a lot of reasons, but I'm the early days their research really was looking at how to boost food productivity and such for the mass of people. I'm pro Socialism and VERY anti Soviet. But they may have some good stuff.
@@d.w.stratton4078 The information about soviet union comes to us from the same bunch of people who promote vaccines, drugs, monoculture and the like. Its about 90% false, and it would blow peoples minds to discover what actually happened.
@@CanadianPermacultureLegacy Some scientists move past this hurdle and pay for it themselves. I have massive respect for those people. Scientific evidence is worth more than gold.
I think the deep tap root also has another role. Once the plant ends its life cycle, the tap root dies off, leaving a "tunnel" in the ground, that will help with water infiltration, aeration of your soil, and also roots of other plants and fungi might use it to travel down. This way by having tap roots growing and dying in your soil, you might be accelerating the ability to create a thicker top soil and sub soil layer. In our fields we have found roots of clover going over 1.5 meters deep, that only happens if the soil is loose enough and alive enough, such that it can penatrate. When starting with very young soil, taproots might play an important role in achieving that. Also look at the work of Gabe Brown, who uses plants with tap roots to "drill" through compaction layers, such that other plants might utilize these pathways when the taproots die back, creating a thicker topsoil layer over time. We have a lot to think about and to learn, but luckily if we do good thinks for wrong reasons, it still works, nature is strong :-)
thank you for your drive to ask questions and see for yourself, and your way to present that information to us. I find this a lot more helpful then i know everything approach. I think this is the only way to have good communication, good debates and ultimately, good solutions for our problems. this video is my cup of tea.
This just came up in my feed. Since you published this, Helen Atthowe published The Ecological Farm, a science-based book on ecological farming. It's right up your alley. One of the big points she makes is how much of the nitrogen in leaves chopped and dropped on the soil surface actually volatilizes as a gas. If applied to the surface, some nitrogen does end up mineralized in the so but to maximize the effectiveness of chop and drop for nitrogen retention, it needs to be somewhat mixed into the top layer of the soil. Also, if you hit google scholar, there is an interesting 2021 SARE doc on dynamic accumulators that has more information than I've seen.
Did the same research myself a while ago (science nerd med tech here) and came to the same conclusions. Most of my perennials have a food purpose - berries or fruit - but I do have lots of comfrey that I chop and drop to add nutrition to the soil. I plant peas and beans with some of my perennials as well as in my annual beds and chop them off at ground level so the roots will break down over winter as the upper parts break down after I scatter them over the bed and/or put them in my compost bin. My comfrey is chopped and dropped and also added to compost. Do appreciate the deep tap-rooted annual plants for their ability to break through our hard soil - and then break down in the soil over winter then the plants die. To me the most important thing is to incorporate a lot of diversity and put all that stuff back into the ground, one way or the other.
Plant leaves and stems have nitrogen in them. If you chop pieces off a nitrogen fixer and drop them next to another plant, you're supplying nitrogen to the second plant without depleting the soil around the first. Even without the nitrogen fixer cutting off root nodules, that's still something.
Oh goodness gracious. You are addressing some of my pet peeves. I’ll start with comfrey, it’s tap root and chop and drop benefits. The tap root is not only a stabilizer, it is a channel for air and water deep into the soil. A plant doesn’t have to delve deeply into the subsurface of the soil in order to successfully access multiple nutrients. The stems and leaves may only be from the top 5-8” but so what? The leaves are still chock full of diverse nutrients. One of the main benefits of chop and drop of comfrey is the rate of decomposition. It’s extremely fast. The plant is engineered to return all of that nutrition to its own root system precisely because its growth rate is so high during the season. So if I cut back my plants once the stems droop to the ground, chop up some of them around my apple trees as well as the comfrey plants themselves I am helping the comfrey to share its wealth. If deer and raccoons and wild pigs were allowed to roam through my food forest they would spread these materials for me. I’m just acting like a wild animal in mother nature’s scheme. As for nitrogen fixers each plant benefits from its own storage system while it is alive. Other plants close by don’t have to share the nitrogen that has been delivered by other systems. Once the plant is dead it’s storage load does become available to other organisms. But killing a nitrogen fixing tree to feed another non-nitrogen fixing tree is - well - stupid. Rain carries a higher nitrogen load that a root systems’ storage capacity. By the time other plants can access those storage nodes the rain would have provided for their needs. Annual herbaceous plants are another story. Once the clover dies back in late autumn the winter seasonal plants can take those nutrients to help them deal with severe conditions. Back to the nitrogen fixing trees. These are pioneer trees. They show up in areas that are transitioning from grassland, scrubland to forest. There isn’t a vast web of deep root systems to take advantage of. Conditions may be arid until the evapotranspiration systems can be re-established so rain may not be a reliable source of nitrogen. In this case the pioneer trees are especially designed to thrive whereas other more valuable trees may not do well, without drawing on the nitrogen stored in the soil/water/salt/plant material. They are usually fast growing and short lived. They develop root highways for future plants, break up hard pan soils and replace carbon quickly while leaf drop build top soil and slows erosion. Around here alders are known as widow makers because their branches don’t hold up well to not-very-strong winds. They are dropping their carbon load regularly. Their photosynthetic produce is different from grasses, weeds, shrub and vine layers so are also tailoring the soil life to support longer lived more valuable forest. And I’m not talking about more valuable in terms of how much a lumber baron can rape the land for. I’m talking about long term healthy sustainable forest tailored by Mother Nature. I would love to site the original research but the sources are varied. I can tell you little of it comes from the US where I live. Mostly from the UK and Scandinavia is what I remember. I can tell you that the agriscience department at Eugene OR has corroborated some of the research’s validity.
If one was a skeptic, but still open minded, not enough to take a youtube comment as evidence (absolutely no offence meant to you or others) where would one find the information that you speak of? eg; " The plant is engineered to return all of that nutrition to its own root system precisely because its growth rate is so high during the season" Is there somewhere I can confirm this in order to help and/or teach others?
Hi there. What a wealth of info. Would be terrific if you were to create 5 minute content videos like this response, as you walk thru your forest. Some info might be applicable to others more or less but the thinking process is what is common to everyone. 🙏🏼
Thanks for the honesty. I suppose I practice permaculture and no dig in a loose form. However I get put off by the sort of fanatical zeal that sometimes comes across from permaculturists on UA-cam. I'm glad I came across this video because I hope it is the start of more balanced approach. I feel that more scientific study will improve what we're doing. At the same time I think we should go ahead and keep doing what we find works for us. Chop and drop has proven results for me, in my garden. I haven't planted nitrogen fixing trees because there are aren't any that will do well here that I want to grow, and I haven't been convinced of the benefit. I find that any healthy plant improves the soil so I don't feel I need to spend resources on nitrogen fixing trees. I am interested in looking into increasing the native nitrogen fixing plants in my garden.
Hell yes. This is my channel. I like thinking on what the old wives' tales were, and if they were accurate given what we've learned since. I'd like to think they're usually right but maybe for the wrong reasons or slightly right but didn't know about the better options the internet, science, and time has shared since. Great video.
When I was in Horticultural College, we were taught different types of digging, one of them being double digging. During this process you dig to a depth of 2 spits down. However, my lecturers always said, never mix topsoil with subsoil, because subsoil is 'nutrient-poor' ... which is interesting, because if deep tap-rooted plants are growing roots way down into the subsoil (and they are, because I've plenty of experience digging down to hoick out persistent weeds), according to my lecturers, they can't be bringing up much nutrition from a layer that's known to be nutrient-poor. So my guess is - it's going to work if you're lucky enough to have really deep, rich soils. Since many of us don't (my soil being very thin and rocky across much of my garden), deep tap roots are a waste of time for conveying nutrients. That said, I do grow a few types of chop and drop around the garden because I am very keen to 'build' topsoil - Comfrey, Oriental Poppies, Ferns (inc Bracken, which makes a lovely dark, airy compost), the highly regenerative Heracleum sphondylium, nettles, lots of different types of vetch, and even the dreaded Rosebay Willow herb has donated a great deal to soil building. I don't remove grass before planting either. Lots of people criticise me for this, but I garden on a steep slope and if I was to smother the grass and kill it off, the soil will just wash away in the Autumn rains. Grass is a pain to control, but it's the best thing for holding the soil structure together.
So my understanding is that taproots are not grabbing "nutrients" from deeper sources but minerals. You're absolutely right about topsoil being more fertile, but the different root depth is supposed to draw up minerals not accessible to shallower roots. The Holistic Orchard by Michael Phillips is my source but it's not a scientific text so no cited studies from him.
@@dragonfireink139 wouldn't those minerals also be present in the topsoil? Clay is mainly made of silicates, magnesium and calcium - those aren't used in significant quantities by plants, unlike N, K, P
I thought chop and drop was just a slower way to compost in place while acting as a mulch. Like how nature would do it but where we want it. Isn't the point of nitrogen fixers to harness their dieback to feed nitrogen and not the plant itself? The dead matter itself feeds nitrogen and the barest line for nitrogen fixers is they can survive the repeated dieback. I'm not sure if it's just what I've grown but have definitely had root die back in my containers after pruning for clones. It also stimulated rhizome production. The deep tap root stuff, I have no clue about but you have proven it makes a great root wall to make a border.\ "When someone's telling you something challenge their background and qualifications for telling you that thing" I'm afraid I'm going to need your background and qualifications for telling me that.
I love the openness and honesty here! And also the acknowledgment that just because there's no science behind something, doesn't mean that it's not helpful, we just don't know the mechanism involved. Yet. There is very little else that you could say or do that would more firmly confirm for me that I made the right decision in subscribing to your channel!
I think so much of permaculture is really based on observational data because we just don't have good research on it. So it makes perfect sense to me that the practice itself is likely sound but the justifications they offer are inaccurate. Medicine still works that way, often. When I took psychopharmacology (it's been a decade, so this could be irrelevant by now), we still had no idea what the mechanism of action was for lithium, but that doesn't mean doctors don't still prescribe it. Thank you for being a scientific resource and voice in permaculture! I've struggled with exactly this - feeling pulled between the two minds science and this innovative making it up as we go kind of practice. But I still feel much better about this model than more traditional gardening, even the organic versions. I really appreciated this video!
Indeed it's a great point. I touched on it in a few replies to comments, but the absence of research isn't proof to the contrary, it's just absence of proof.
Nice! Happy to see this kind of thinking promoted here. I had a few small comments of things that went through my mind while watching. Nitrogen fixing is not a vestigial function I would assume, so the plants are doing it because they need nitrogen. For example, the nitrogen in bean plants is used to actually grow beans. Amino acids in sea buckthorn come from nitrogen as well I believe? Sacrificial plants would need to be sacrificed at a stage in which they have stored a lot but haven't yet used it I would imagine. Chop and drop is good because the leaves are not only carbon created from solar panels like you mention, but it's also the vitamins and minerals that are in a plant available form. The soil food web not only feeds off exudates but also the greens like things that are chopped. When predators like nematodes eat that bacteria they die, then those minerals are available to the plant. Otherwise the bacteria and fungus would be presumably spending more energy harvesting from rocks, soil, minerals instead (or maybe whole other species do that more likely). It's also free mulch and additional habitats for insects. Anecdotally, after I mulched my exposed sunchokes which kept wilting on the heat, not only did they not wilt anymore, but spiderwebs started to cover the whole surface between them. Less importing of organic material from other places like chip drops or Home Depot. Taproots are also for water access as well, yes? Same argument for nitrogen then where it's not using as much of the higher water table and it's available for other plants nearby. I imagine that means chopping the leaves provides moisture up top from down below? But also the physical act of drilling a taproot down creates a pathway for things to travel upon which it might not otherwise have the opportunity to. Bugs and other soil life can move both up AND down. And when it finally dies, that rotted taproot is a benefit on its own just like any roots, except across many different soil layers. Chop and drop is still always going to be like composting, just the "unmanaged" way nature does it instead of in piles like we do. You need to take weeds and trim stuff anyway and it's either free mulch at the minimum or a compost ingredient in the bin or on the ground. Thanks again for doing what you do! Any thoughts on how to address things like this you've previously said in old videos for people just seeing them for the first time before this video?
Amazing comment, all of it. I agree with it all. So many benefits of having robust root systems in the ground. Chopping and dropping, even if they don't actually disassociate the root tissue, and they only shrink it, that's still going to function as more low-resistance water pathways to get water deep, which likely also causes a microbiology explosion, etc. For the last question, the only way would be to take the video down, but what I can do is recommend this one at the end of those ones. It's likely that some of these comments are pervasive in most of my earlier videos, and there's so much good content in those that I think I'd be throwing the baby out with the bathwater to eradicate any error by deleting videos. It's definitely a tough balance. I will try to mention these things in future videos. One other thing, I find that older videos get almost no views after the first month or so. I think that's just how people devour youtube content. It's also for that same reason that I'm going to focus on "redo-ing" many topics each year, or every 2 years. So many new viewers for example will never run into some of the more important videos I've done, just because they are searching through so many of them, and the habit is to watch the newer stuff.
@@CanadianPermacultureLegacy if I had to guess, I would postulate that the drop off is that your channel primarily seems to be updates on your garden and progress of this or that. Your most watched videos seem to have concise titles conveying a single topic. The other ones are often more ethereal, and meandering around the garden talking about several points as they come up. Those won't trigger keywords and be searched for often. Nobody is specifically looking for a bunch of people's "updates on chickens". That's not to say they won't enjoy it if they came across it though! I particularly enjoy these because it's fun to see everything in context, but the titles and content probably don't trigger the algorithm to show those kinds of videos to people because it's hard to draw a line between those and other kinds of videos on UA-cam. Whereas "Starting a food forest? My top 6 berries" or whatnot connects to everyone beginning to look into food forests. "An update on the chickens" vs. "3 things I learned after starting a chicken coop" shows maybe how to connect into that more? Anyway, what are your goals? Do you want to monetize? Do you like expressing yourself? I enjoy the updates because they are so relevant and timely, being in a similar climate myself. I don't use your channel for "how to's" I use it precisely for the educational meanderings and that you have a good presence on camera. Playing the algorithm game and "top 3 things" and "5 mistakes I made..." exclusively is exhausting and clickbaity if that's all a channel is IMHO. And the incentives might not be aligned with your intended goals here - you'll have to decide. Edible Acres seems to have struck a nice balance though. Many of their titles are very concise despite always having a bit of meandering as well. Neither of you are the flashy "top X" gardening channels that are annoying which you speak of, where sometimes they don't back up their claims with evidence. Anyway, I watch 90% of your stuff so I don't have any problems myself 😋
Yeah great comment. I've thought a lot about that. If I want to min max and grow as fast as possible, the best way is with "top 10 plants yoy should grow" videos. Or "Walmart hates him, this guy is growing all his own food for free", or similarly stupid things. But I don't like that kind of thing, even if it works, so it's just not me. Then there is the topic based videos. Sometimes I get a hankering to do those, or a activism style video. These take substantially more time to storyboard, film, and edit. 10x more. They are fun to do, and I enjoy making the odd video that is more highly edited. I think its also a good way to bring in new people. But my favorite videos are when I go out in the morning and just walk the land, see something neat, get an idea, and start meandering and discussing. I find them very therapeutic. I also find myself learning more about my land by observing, filming, thinking about what I'm filming, learning from it, etc. Long answer that my focus is definitely not on channel growth, and absolutely not at the cost of being annoying. I know it works. I just hate it so I'm not going to do it. I may do the odd one here and there as a test, so if you see an annoying face reaction thumbnail with a clickbaity title, that's probably me running an experiment, and it will be very infrequent. My main goal is to have fun doing this, because as soon as I don't, I will stop, because the money quite frankly sucks LOL.
Very refreshing, great video! I love that you are honest, inquisitive, and straightforward. So glad I found your channel. My hubby and I are just getting started in permaculture. Very helpful!
I'm so glad I finally watched this video. I had been wondering about that very thing even through I heard it from nearly everyone. I've not had time to do tons of research, so thank you for that, too. I plan to have a small "food forest" on my second property. I'm now working on reducing invasives, replacing them with "free growers" that don't need much attention, researching native plants, deciding which ones I and extended family will be more likely to actually use, and planning layout, etc. Realistically the plantings won't begin for a few years when I can actually move there. The part of it that is not forested is just VA red clay so needs all the help it can get. The past few years I've let the grasses grow & mow them occasionally so I hope that has helped somewhat. Now I will make an effort to plant at least the areas where I plan to garden with annual and biannual plants to let their natural cycles improve the soil as well as support pollinators and wildlife. There are already some wonderful volunteer raspberries that produce a really nice crop. I've actually managed to maintain them pretty well. It's easy to take a gallon in a 20 minute pick session. I wish some birds would be nice enough to plant some blueberries for me, too!
So nice to hear someone step back from the regurgitating tendency. It's definitely a difficult tendency to break. Like most my initial knee jerk reaction was what you are going to say nitrogen fixers don't improve soils, but I stuck with it and I have to agree on both accounts. I can't say I have ever seen evidence that they feed nitrogen back into the soil except in situation where they are culled completely. I have seen some limited transfer via mycorrhiza. Also I completely agree most people completely misunderstand what the purpose of a tap root is. This is extremely common in tree growing communities, people often believe that the tree dies if the taproot is severed, but that is completely false. It's done all the time in the nursery industry on purpose. Definitely gained a subscriber as a result of your honesty. Keep up the good work.
Exactly. N fixers have a huge part to play in a system. Even if all they do is grow leaves using N from the air instead of the soil, that N is returned in the fall during leaf drop. It may not be "fixing" nitrogen in the traditional sense of rhizobium bacteria, but they are still improving nitrogen (and carbon!!) in the soils by dropping leaves which were mostly created from thin air and some rain.
A suggested process from soils classes is that the soil fungi tap the roots on both a nitrogen fixer and the other plant and trade certain materials from both plants back and forth acting as a small trucking company so the plants don't have to die off to share their nitrogen. That the plant release certain exudates to trigger certain fungi to bring in iron or phosphorus etc. And nitrogen is on that list. So if nitrogen can be shared even at low levels it has value. And this would seem to be fairly likely as the gains from aerobic fungi and compost teas don't make real sense unless this is at least partially true. Still learning here too. Now as for deep root feeders even if 99.9% of stuff comes from the top 4 inches you are still gaining 0.1% from deeper. But the other thing you gain is a pipeline feeding and carrying soil fungus deeper and building soil carbon and therefore water holding capacity, nurtrient banks and making the soil more oxygen permiable. So now say the soil is good enough 6 inches down to support that web of life. Now you have 50% more available nutrients for plants.
This is all very interesting and I'm so happy you're uncomfortable with just parroting what everyone else is saying! I'd love for you to take a look at tomato pruning. SO many experts say you get more tomatoes if you remove the suckers and now they're pushing removing a lot of the lower leaves, too. My gut says the extra foliage supports more nutrients for the plant and deeper, more extensive root systems that should make the resulting tomatoes from the bushier more natural plants have more flavor and nutrients. I'm tempted to get a brix meter and try some each way to compare the results but I don't have a UA-cam channel to spread the results. One thing I was thinking about your nitrogen fixing discussion, tho, was the role of mycorhizzal fungi and whether they set up a network to share the excess nitrogen with surrounding plants. Stephen Harrod Buhner and Paul Staments in some book or other mentioned that it can take 10-15 years for some parts of the network to develop, so a lab study couldn't reflect what would happen in an actual food forest. So again, maybe something like a brix test would be more useful in testing in the field whether a benefit is happening or not.
Great comment. I'm nit sure I have the time this year to do the experiments...I know I don't. But I may look into it in future years. The mushrooms can definitely transfer nutrients, which is one of the main reasons we mulch with woodchips.
Not sure in what talks but John kempf has mentioned this sort of thing. Healthier plants get more efficient photosynthesis so don't remove leaves. And his podcast episode with Greg pennyroyal touches on a moment about a similar concept with grapes in viticulture as its also a common practice to stress the plant for a "better" harvest. Forgive me, I think he kind of sprinkles it into a lot but he's plant health focused so it's his mindset.
I saw this at just the right time!! As always, your videos and approach to building a sustainable food forest has been truly inspirational!! My brand new FoodForest exists because of your enthusiasm and knowledge offered.
Subscribed to the channel. Watched some videos and i have to say this is the first down to earth food forest channel i have seen. Most plant on buckets and call it a forest.
Thank you for your deep dives into these topics, There are a lot of channels talking about them, but not so many doing it at this level. I'm happy to get the information from you, even though this isn't the field you went to school for. It's better that we learn to evaluate information based on the information itself. We're smart enough, and experts are often wrong.
I like that you are challenging these statements that are parrotted by so many people. One thing that would be worth discussing on the topic of nitogen fixers would be annual (short cycle) cover crops like fava (broad) beans and whether cutting them down before they flower/produce beans is effective in adding net nitrogen to the soil for other plants (versus them just being less needy with nitrogen than other plants). It is similar to your lupine example, but on a shorter time scale, albeit requiring more intervention than a natural lupine system..
I'm an engineer as well. My aptitude is also mechanical but my particular strength is the ability to see what is happening, understand what is really going on and adjust the process to be more efficient and productive. My limited experience is with beans and peas. It kind of evolved in my head that they really don't build nitrogen for anything but themselves. I came across something the other day that said the nitrogen (in a fixed form) exudes from the nodules into the soil. I have no idea how true that is. However, it came to me that the store of nitrogen by the bacteria might be used when the plant is flowering and fruiting. this makes sense to me. So after you pick the beans and peas, maybe there isn't as much in the roots when the plant is cut as we might think. I have been using fava beans to fix nitrogen, then cut them just as they begin to flower. The biomass is composted and the roots are left to decompose and release the nitrogen. Now it's in the soil in a form useful to other plants. The "green" of a plant is also full of nitrogen and available to bacteria during composting. If the biomass is dried, the nitrogen is NOT there for the composting bacteria. When peas are finished I pull them and plant the next crop of whatever. The roots don't seem to have very many nodules on them. MY conclusion is, even though the bacteria might still be there, the plant was taking everything to make fruit. As you pointed out, I have no basis except my own observations. All I can say is... it works the way I'm doing it. And producing FOOD is going to more important than ever soon. Real soon.
This is also what I'm thinking, but as you said, I haven't any proof either, other than analecdotal evidence scattered here and there when pulling a plant. But no controlled experiment, and honestly, no time to actually run one. It would be nice if more research was done on this.
Great analysis. I appreciate your scientific approach to each subject. It is the faithful application of the scientific method that tends over time to lead us closer to the truth. With any common practice which has stood the test of time there are three possibilities: it works for the reason they think it works, or it works but for a different reason, or it doesn't work.
Third year of no external imports to my garden. I soil tested my bed after I pulled my potatoes and onions last year, kinda low in nitrogen. After harvesting, I planted some clover. Never flowered before going into winter. This spring I terminated the clover via solarization. Note, I used a pitchfork to loosen the soil, heavy load of snow this winter a bit of compaction and direct planted into the soil. I know by solarizing, I wiped out a lot of biology, I placed a handful of home grown vermicompost into each potato hole and top dressed the rows of onions after planting. I then covered both beds with aged straw to protect the soil. I normally use shredded leaves but 2 years ago the jumping worms turned my soil into garbage, another story. In your opinion, was this the best course of action with a clover cover crop, and would hairy vetch be easier to manage. New subscriber! Dr Ingham changed the way I garden, wish I could afford her course. I did get a microscope. Stay Well!!!
One other method without having the completely kill is to use Geoff Lawton's strategy and take a long spade and cut around the root ball to disassociate the nodules from the main root. Leaving the plant or tree intact ready to grow the next season
Love the skepticism of the info out there. As a scientist myself, I feel the same way about the many, many unsubstantiated claims out there. Adam from Learn Your Land will show specific research papers in his videos. I think that would be pretty cool if you also did that.
Thank you for making nice and informative videos. I'm from Finland and it's nice to have a Canadian channel with at least somewhat comparable suit of plants that can grow.
I prefer to use the term biomass accumulation. Different plants contain different mineral ratio. I plant lemongrass, Vetiver and Mexican marigold in sandy, unfertile soil and they do great. I chop and use it as mulch while adding biomass or add it to my compost pile.
Love this video, I definitely just accepted these ideas because I had heard them so often. It's a known weakness that people are more likely to accept things as true the more often they've heard them repeated, so thanks for reminding me to challenge that.
I don't know why UA-cam hasn't been showing me your new videos as much lately, but this one just came on my feed. Very odd. But this video is the very reason why I love your channel - you are willing to own your own voice and dig deeper. I don't know much about science, but we all seem to walk around "parroting" as you said, without thinking twice about our own real knowledge on the topic. For me, the biggest garden lesson I learned last year from a channel called Agroforesty Academy, is that eucalyptus has a bad rap that they don't deserve. I am in So Cal where eucalyptus grow like weeds. Everyone in the gardening community here will tell you that "nothing grows under eucalyptus". But the truth is that the trees grow in very poor soil where nothing else is growing...if you heal that soil just like any other location in your yard, they absolutely will grow things under them & are a fantastic source for fast growing mulch! I have 3 massive eucalyptus on my property, all of which now have things growing under them (including veggies, wildflowers, natives, succulents, etc!) because I have made the effort to TRY...because I pushed to learn more and knocked down a myth. I will be cutting them shorter soon just so I have better access to their canopy for regular chop & drop/mulch. Sorry for the book...just agreeing that it is SO important to do your own research for your own situation! Thanks for all your efforts.
That's such a common thing too. I love this comment of yours. The hatred on so many nitrogen fixing trees (many many of them are on invasive lists of conservation authorities) is similar. They are "invasive" in poor soils, because they can get Nitrogen from the air. So when humans cut down forests to build subdivisions and highways, and these pioneers dominate the new disturbed dead soils, they are labeled as invasive. They aren't invasive, they just dominate their niche. As the soil builds from their own leaf drop each season, their niche slowly disappears and other plants now will outcompete THEM. Often humans have such a short time span that we don't see these longer term implications.
Keith, Great video and there's probably some sort of symbiotic benefit among various plants living together. Lots of complexity in mother nature and we probably will never completely understand it all.
I enjoyed this video. It is refreshing to see you challenge some of your own ideas! I have a few thoughts that don't necessarily challenge what you say but are meant to add some context: 1. I am in favour of scientific research but in doing a great deal of reading in agricultural research, have come to realize that a great deal of science does not deal with whole systems but just with a few isolated variables. You illustrated that brilliantly about nitrogen fixers and whether or not they make nitrogen available to other plans. A scientist might try researching for that one variable (nitrogen made available) but miss the contribution of that plant to the whole system (carbon through root exudates etc.) I am encouraged to see that a new generation of scientific researchers is coming up in universities that is working with actual farmers in a variety of settings and are trying to look at the big picture of soil health over a number of years rather than focussing on small trial plots on a research farm. 2. Do not tap roots also create a great deal of drought resistance? When almost our whole lawn is brown, the dandelions (and some of the legumes I've been adding) are still green. I understand that to be because they are bringing up water from deeper in the soil. I have been adding comfrey to our berry and fruit tree area and am amazed to see how it can flourish in the heat of summer when the surface is getting dry. That alone adds immensely to the soil as it continually grows, providing organic matter that can be chopped and dropped where needed. 3. Tap roots also play a role in breaking through hard clay soil. Many regenerative farmers include things like daikon radishes in their cover crops to break up old hard pans. I am happy to see the comfrey flourishing in our hard clay soil. 4. My understanding of pastures (and that may not be true of things like sea buckthorn) is that if more than 50% of the growth is removed through grazing, some of the roots die. If more is taken, more roots die back. Keep up the good work!
All fantastic points. #2 is especially important, because the tap root not only accesses the water deeper, but also provides the low resistance pathway to allow it to actually get down there.
A thought experiment on nitrogen fixers: Suppose you have a nitrogen fixing plant, to my knowledge there are only two ways this plant can get nitrogen. 1) From the air 2) From the soil When you chop and drop this plant, you're adding whatever nitrogen was accumulated in the leaves, stalk, etc back into the soil web. However, some of this nitrogen is lost during decomposition as off gassing. I would assume that whether nitrogen is actually added to the soil would be dependent on what % of nitrogen in the plant mass was attributable to 1 above, and whether more or less nitrogen than this was lost during decomposition. Basically you're just trying to find the balance of nitrogen gained freely (from air) and nitrogen lost (from decomposition) It seems to me you don't actually need to disassociate the roots to free the nodules themselves, let the nodules feed the leaves and the stalks and then use them as green manure. Thought experiment 2: To think of this in another way imagine you have two cover plants, one a nitrogen fixer A, and one that's not B. Plant A hypothetically should outgrow B in nitrogen poor soils. When you chop and drop both, there should be more of mass A dropped than of B, as it's a larger plant. If you take the difference in mass, and then find the nitrogen associated to this extra mass, you should theoretically have a rough idea of how much extra nitrogen you've added to the soil via the nitrogen fixer. If there's more of this nitrogen by weight than the entirety of the nitrogen lost by plant A in decomposition then you'd be adding nitrogen to the soil via chopping and dropping.
For sure. This is the main reason why I think they are still worth growing. This video wasn't so much about mythbusting if nitrogen fixers are useful, but just Mythbusting the claims that are made that once planted they pump nitrogen to surrounding plants, which I've heard in permaculture so many times.
I think a big part of N fixers is the fact that there bringing in organic matter from the air and are “pioneer” plants meaning they can settle in very poor conditions, and then slowly making it suitable for other plants until one day it’s an Amazon forest!
Glad someone is addressing this. I always wondered if the fungi could fix nitrogen from digesting regular plants, or how much nitrogen is fixed in the guts of bugs that eat the plants, or how deep below the active layer the soil fungi can reach to extract minerals from rocks. I do know that some plant taproots do extract water from deep below the surface (like faidherbia albida) so that may also bring other nutrients up.
Old school farmers around here still do a season of red clover, which I seeded heavily in my backyard; this year - this week in fact - I decided to scatter lupins around, too. Mythbusting would be awesome as a regular segment! You could voiceover the view of the pond. Just on the subject of taproots, those do bring water to the surface, allowing for a huge amount of carbon fixation every season. I grow bullthistle just for the biochar (and because it brings in the sweet little goldfinches haha). Thanks for addressing a major peeve! It always disappoints me when someone I consider an authority spouts some clichéd nonsense without a second of critical attention. But I do hear marigolds flowers will give your chicken eggs a gorgeous colour!
@@CanadianPermacultureLegacy please let me know how you go. There are plenty of others doing regenerative agriculture which includes MS cover cropping. I'd like to see another video about it when you get a handle on the science. The entire NPK system we currently use is so stupid. It's killing the earth and doesn't work on any level. Regenerative agriculture will probably go against everything you've ever learned. Welcome to the new old ways. 💖
@@CanadianPermacultureLegacy so you are many years into regenerative ag but still can't find science to back up multi species cover crops? Dr Christine Jones explained it pretty well I thought. You said you didn't understand how it works. Why not just ask her. Never mind. I apologise for wasting your time.
Happy to see this video because I've been confused about this topic. Logically I know that leaves and grass clippings start out as green, nitrogen rich sources - but as they dry they lean more toward the carbon end of the spectrum. I wondered why Comfrey seemed to be the exception to the rule. So maybe its not.. but I still want to grow it!
Thank you for your thoughts in your video, and thanks to all you people with your amazing good reactions! As permaculture is only a few decades young, it still needs to grow more educated. My thoughts went to the native nations use of beans in the ‘three sisters’, especially when not planted together in a guild, but in a sequence. I was told (…) that in this case the beans were always grown in the year before the maize was grown on the same spot. This might hint on some advantage of the nitrogen fixer to later crops. Centuries of trial and error or, better, observation could bear some knowledge or practical science. As I work in gardens in Amsterdam, NL, it is hard for me to go and check this kind of knowledge, but you might.
and to be clear, I'm not saying nitrogen fixers don't work. There is a long history that they do work. Even if they can grow leaves and get their nitrogen from the air (leaving more soil based nitrogen for other plants), then they are a benefit. The point of contention is that the nitrogen nodules themselves help other plants, and also that some people claim that the nitrogen fixers pump nitrogen to all the surrounding plants.
There's a section in Dave Jacke's 'Edible Forest Gardens' book that talks up the importance of nitrogen fixers for a while and then ends by saying something like "we're not sure how long it takes for nitrogen fixers to actually translate their nitrogen stores into benefits for surrounding plants, could be 10 years, maybe longer. Don't ditch the compost early on." When I read that I remember thinking 'huh, that's a disappointing ending to that nice sounding principle' Honestly though, it just makes the design easier - grow a diversity of plants, let them do their thing, it doesn't have to be complicated. Thanks for the video, good to question everything, especially the things that make us feel warm and fuzzy
I highly appreciate you sharing the information, experience and knowledge! Big thumb up to you for doing your own research and study then speaking out your mind frankly. As humanity stepping into the new Aquarius age, this is exactly the spirit that people need ～ collaborate and help each others, yet speak out your own idea/mind 👍👍👍🙏🙏🙏❤️🌹
Nitrogen fixers do work, but they of course don't shed their nodules... The benefit is that they can grow fast without outside input of fertilizers and they produce high protein biomass (for legumes at least), biomass rich in protein decomposes into nitrogen rich compounds (nitrates, nitrites, ammonia) which in turn benefits other plants around...
Fantastic video. So many good ones lately (and I always love the geek-out science moments!). My "nitrogen fixers", you are right, may work for different reasons. Shade is a big thing here in dry PNW summers and my main "nitrogen fixers", Comfrey, Goumi and Sea Buckthorn, all grow fast and provide good shade. The Sea Buckthorn and Goumis I would also grow just for the fruits. The Comfrey (yes I stupidly grew 'True Comfrey' from seed so yank off the flowers early and often) is so hearty via that taproot that I can constantly yank off those leaves to cover soil so have to water less in our dry summers. At least for the Comfrey, a big X factor for me is laziness. It's just so easy to drop those Comfrey leaves at the base of the plant and tree and not have to haul anything (I usually do it while watering). So, even if they don't "fix" nitrogen as I think you are probably right, they still tend to work for me. ...and totally agree that more plants of any kind help the soil. I have seen that working for sure!!! ....and also part of the lazy X-Factor....I always pee on plants in the yard rather than go to the house and waste water (in Spring and Summer anyway when the leafed out trees/shrubs keep the neighbors from getting an unwanted show.). Sometimes you have to be your own nitrogen fixer!😜🤷♂️
Yeah, and reading through all the comments (such as yours and many others) there are just SO SO Many reasons to do these things still, even if some aspects of them are in "myth" territory. Deep rooted plants provide low resistance water and air pathways down to the ground. SO they are still something we should include in guilds. Chopping and dropping things, even if it doesn't disassociate the root tissue, still shrinks them, doing the exact same thing, low resistance pathways get created. So many factors at play. The best thing we can do is just replicate nature as often and accurate as possible.
I think you are correct on sacrificial plants. There is a lot of sound science with nitrogen fixing for cover crops (beans, peas, buckwheat, etc.) for fixing fields. Many of our farmers here in Kansas grow soy bean as a cover crop for this reason. The proof being in that the soils are not needing fertilizers in the coming years. Also, one big challenge commercial farms have currently is the lack of crop rotation and cover cropping. Where regenerative techniques are in place and planting multiple species they are increasing the interaction of nutrient exchange.
The key difference is there is a lot of good research on optimal time to till the beans/alfalfa under in order to maximize Nitrogen addition. Without the till, the beans are really just growing without taking N, which in itself is pretty good. Most of the N replenishment then comes from rains.
@@CanadianPermacultureLegacy In the regenerative fields they are not tilling the fields and increasing the yields without fertilizer. The fields they are tilling are having troubles. There are a lot of grant programs encouraging regenerative techniques and avoiding no till. I'll look for the studies and post.
In my experience, the benefits of comfrey are overstated. I'm glad I didn't plant more than I did. I'd rather give the space to a diversity of appropriately-sited native wildflowers/shrubs. In addition, the dictate to plant a nitrogen-fixer with every fruit tree seems tenuous at best, so I've generally ignored it (even on initially infertile soil). Observe, study, then ask yourself what would be growing on your site if humans had not altered it; plant your "useful" plants into a matrix of historically local plants (many of which are also actually "useful" to humans, and all of which are ecologically useful). It will thrive.
@@OakSummitNursery Seriously, strawberry-rhubarb pie is the best pie ever, and I pride myself on baking a fine one! But how much rhubarb is enough in the landscape? A handful of vigorous plants provide more than we can possibly eat. After we eat/preserve our fill, I let them flower for the insects, but as is the case with comfrey, I won't be deliberately multiplying my rhubarb. Instead, I'm searching out and adding in a diversity of native plants for wildlife/insects, e.g. wild senna, NJ tea, dotted St. John's wort, shrubby St. John's wort, steeplebush, buttonbush, figworts, etc.
Permaculture is a fairly new concept however the methodology has been around for centuries trying to ascribe a scientific backing is always going to be more complicated than necessary as we still don’t fully understand the human body let alone the extremely complex systems in place for growth of plants that said Mother Nature provides us with examples ie an unregulated and un manipulated forest the compact and diverse ecosystem with no waste that is self sufficient. Great video.
We have alfalfa and weeds in our organic orchard. We let the plants grow as much as possible and then chop it up with a flail mower. There are drip lines that feed the trees and they are buried up to 10 cm of soil that has been created by this process. All of our peaches are softball size and sell every one. Over time the soil gets deeper and richer. When one walks on it, the orchard floor is very soft.
I love how you have a marker to measure the soil building (the previously installed drip hose). That lets you know it's working and you are on the right path for soil building. Love it.
Thank you so much for this video. I've wondered about the scientific nature of the memes around nitrogen fixers in the garden for a long time. I didn't track my source on this but I read once that you can tell if the plant is fixing nitrogen from the air if the roots have nodules. Last year I pulled up my pea plants and didn't see any nodules which, as I read, indicates that the symbiotic bacteria are not present in the soil. So, I bought an inoculant and will test for myself with pea seeds I have left over from last year's planting... I can't wait to see the outcome this year.
Thanks for stepping back and taking a critical look at some of the tenets of permaculture. They often sound good but that bioaccumulator label on comfrey always seemed suspicious to me. I’ve also never wanted to plant something that is so hard to eradicate that you may need chemicals to get rid of it.
To be clear though, the bioaccumulator label is actually likely true. See linked research in the video description. The contested point is "where" those minerals came from: the deep tap root (deep down), or the lateral roots (surface soil). There is no evidence that the minerals are mined from deep below. However, there IS research showing just how many minerals it accumulates.
unrelated: the biggest advantage of annual seed saving is over your life and lifetime you are cultivating your own gene pool of stable superior crops. i suspect how most crops were domesticated was just that humans and other animals ate what tasted good and ignored what didnt, slowly domesticating them. If you collect data on each plant then in 50 generations of selective mass breeding you could COMPLETELY change the plant.
Nice a little section about media use knowledge. I always wondered about the root shedding, why plants should do that. Regrowing needs a lot of nutrients the plant probably has to get from the soil food web. So it converts the nitrogen into exudates, "feeds" it to mycelium and bacteria, which feeds higher soil food wen beings
I listen to what people have to say about their own experiences and, as you say, actual scientific evidence, but tend to be a little skeptical of anyone who seems to think they can significantly improve on nature. After all, nature has been doing this for, literally, millions/billions of years. In developing my front yard into garden space, my goal is to reach a point where most plants reseed and/or perennialize with little to no input from me.
It's honestly such an important way to think. As soon as we start radically departing from what nature has done for billions of years... and each organism has slowly evolved to excel at... and the orchestra of billions of them all working together in this intricate web... it really makes it questionable when we start doing things that doesn't COMPLETELY mimic what nature does. Amazing comment.
I have to say, the loud buzz and drone of leaf blowers every fall makes me despair at the ecological illiteracy of my neighbours. All those leaves are the food for the trees they love having in their yards. Plant Nutrients in Municipal Leaves (1998). Joseph R. Heckman, Ph.D., Extension Specialist in Soil Fertility; Daniel Kluchinski, Mercer County Agricultural Agent; and Donn A. Derr, Ph.D.. Rutgers Cooperative Research and Extension. Fact Sheet FS824
I'd be such the annoying student in a PDC because I already know all the techniques, so I'd have my scientific skeptical brain going strong, not having to absorb the techniques. Never yet have I heard anyone explain the dynamic part of dynamic accumulators. Maybe you have? Elaine Ingham does tell a story of measuring the rate at which nutrients move from the roots to the tree tops, by having some researchers hike down into a cave and injecting into the tree roots, while other researchers stayed at the top looking for the markers to appear in the sap. I forget the tree and the timing, but it was extraordinarily fast. I'd also point out that there is always leakage in nature. No nitrogen nodule is going to be able to contain 100% of the nitrogen it fixes. So some of it is clearly going to be found in surrounding soils and plant tissues. In a forest situation the roots of trees are all intermingled. I figure there's a lot of give and take happening. People have this mindset of tree root structures as this perfect dendritic sphere, but then when you look at the drawings that researchers have done of tree roots, they are much more irregular.
@@ediblelandscaping1504 artificial fertilizers? But the statement "There is zero soil biome" is a bit strange. there is an aerobic environment from the water constantly being stirred. this facilitate microbes, so there should be something.
it's similar to how till agriculture fertilizer systems work, or pure chemical based hydroponics. It's all capillary action that drives the water and nutrients into the plant. This can happen with no microbiology, but chelation cannot happen, so the fertilizer must be chelated, ie. in a plant available form.
our hay meadows are primarily timothy clover. yields timothy predominance one year, then clover the next. the family has done this since (and probably before) 1800. one meadow, in particular, has been in production since 1980 with no addition of nutrients (including manure).
I’ve definitely heard the about shedding nitrogen from the roots, whether that’s beneficial who knows. There is the release of gibberellic acid when pruning which is said to help neighbouring trees grow. As for chop and drop depending on how fast the material decompose I’d assume that a lot of the nitrogen could just off-gas, the same way there’s a difference between nitrogen rich green grass and carbon rich dried grass.
What's cool to me is that we don't really know how or why it works and yet we can still help have a positive impact. I think that natural systems are so complex that we will probably never fully understand it all and they are so regenerative that as long as we aren't taking too much, nature is always working harder than we ever could to restore itself
A brilliant point. Anything in this area needs to be approached this way. The natural world is so complex and we know so little about it, that the absence of proof isn't proof it itself. So get out there and try it, see what works, and operate in the empirical space of trial and error. We may always know EXACTLY why something works, but we can control as many factors as possible and isolate good practices, and do those. And the best way to start is to look at nature and replicate what nature does.
I love your honesty and your desire to only promote concepts that have scientific backing. I do believe that Nitrogen can be transferred to other crops by stripping off leaves and twigs from Nitrogen Fixers and then INCORPORATING the leaves into the soil near the other crops. As these leaves rot down, the Nitrogen in the leaves should become available to the other soil. This seems to be working in alley cropping systems here in Zambia (see Gliricidia sepium a Wonder Tree for Small Scale Farmers, on You Tube). As far as recovery of nutrients from deeper down in the soil by deep rooted plants, I wonder if trees (as opposed to shrubs like Comfrey) might be more effective at recovering nutrients from deeper down? Under our conditions, I believe the trees (in an Alley Cropping system) are definitely providing photosynthetic energy year around, compared to the 100 days of a typical summer season maize (corn) crop. BTW I'm also an engineer (civils) and so am also very skeptical about the unsubstantiated claims made in many regenerative agricultural circles.
Yes this exactly. Even just the leaf fall and decomposition, that also. Most of the nitrogen came from the air, and is then put into the soil in the fall and winter.
@@CanadianPermacultureLegacy I'm looking for a different system, suitable for the Small Scale (almost subsistence only) Farmers of Africa. We have cheap labour, so stripping the leaves off new growth twigs and INCORPORATING them into the soil, is an option for us that you would not be able to afford. I believe that (a) leaves dropped in your Fall are probably much lower in nutrients (including Nitrogen) than mature leaves in their spring/summer peak condition (by Fall, I suspect that most trees will have tried to withdraw as many of the nutrients in each leaf (to be stored in their root reserves), prior to allowing them to drop) and (b) I believe that, left to decompose on the surface, most of the Nitrogen in any leaves (stripped or fall dropped) will return to the Atmosphere, rather than be absorbed into the soil. Horses for courses; we each have to find a system that is economically suitable for our conditions.
Watching this video, I realized that I have been parroting the nitrogen taking points. However, I do have some anecdotal evidence based upon my experience. I have a lot of Gliricidia sepium on my farm. Each year, I make some really great, fungal-dominated compost using it. I trim branches and then chop them in a woodchipper. I get a good-sized pile and allow it to compost, turning it regularly and adding moisture (if necessary). The wood chips from the branches provide the "browns" and the leaves the "greens". Once the material has passed through the composting cycle (~18 days), I lay it out in a bed about 4" thick, give it moisture, and cover it. After a week to ten days, it is loaded with lines of fungi. I have used this directly to grow healthy vegetables and fruits. You could say that this is a type of "delayed and processed" chop and drop. In my experience, I have found that chop and drop has value in adding organic matter, specifically carbon, to the soil. I have not found that chopping and dropping a nitrogen fixing plant is any better than chopping and dropping one that does not fix nitrogen. After all, there is nitrogen in the leaves of both types of plants.
Just discovered the channel and love your vibe/mission, so thanks for all that you do! I think it's really admirable for you to admit we might be wrong about these common claims and to get the discussion going. I'm curious though, when you say that there isn't much (if any) scientific evidence to support these claims, is it that there aren't any studies that have been conducted to test these hypotheses? Or is it that studies have been conducted and seem to suggest that these claims are untrue? Your point about the taproot vs feeding roots makes a lot of sense for why the nutrient accumulator claims could be false, since there doesn't seem to be a causal mechanism. But I'm wondering if there might be a mechanism by which the bacteria harnessing the atmospheric nitrogen for these plants could benefit other root systems inhabiting nearby soil, without the need for the host plant's rhizomes to die off. I'm 100% out of my depth on this topic lol, but just wondering if there is still something to the anecdotal evidence and we just lack the understanding to explain or identify the causal mechanism. Just genuinely curious. Keep up the great work!
For the first thing, no I don't think there are studies to demonstrate it. But also I think there are some misunderstandings that are being repeated and parroted about 2 main things: that roots sever when a plant dies back (they don't, they mostly stay intact and just shrink) and second, that the nitrogen nodules are nitrogen fertilizer pellets. They arent, they are just homes for the root bacteria. Infact, the nitrogen nodules themselves are more akin to a factory, than a warehouse, if that helps explain it a bit. The main benefit of a nitrogen fixer is that it is self sufficient, and grows organic material without drawing down soil nitrogen reserves. It then makes plant matter (stems, branches, and especially leaves), and in the fall the leaves fall. A lot of this nitrogen was taken from the air, and is therefore a soil input. Then when the plant completely dies, the entire plant mass (above ground and also the root mass) will be consumed by soil life and turned into soil, and a lot of THAT nitrogen was also "free input". So overall, the process is much slower than permaculture books may have you believe. It's still a valuable member of a guild, it's just not this immediate fertility battery that it is sometimes sold as. It is a long term fertility play.
@@CanadianPermacultureLegacy Wow, thank you so much for taking the time to write out that amazingly thoughtful response! I really appreciate it and that makes a lot of sense. Stay awesome my friend!
Suzanne Simard has shown that the transfer of carbon between trees is mediated via the mycorrhizal systems. She shows intimate communication between plants via this same system. Likewise, we know that the breakdown of organic material in the soil occurs as the result of soil bacteria and fungi and that these nutrients are passed along to plants. Although we may not know exactly how nitrogen, carbon and other nutrients are passed between plants in a guild, we can only establish the optimal balance of plants in guild. Once it can be clearly established that certain plant combinations are beneficial, the next phase would then be to determine why and then to determine the how. The myths are in the how say a nitrogen fixer is beneficial to a guild. However, the scientific role of the horticulturist is to clearly show that a nitrogen fixer is beneficial or not.
It's always good to have that big picture in mind for sure. I always want to know "why" but sometimes we're decades or centuries from being able to figure out the answer. Sometimes we may not even be capable of understanding something as different to us as plants. I talk about this a lot in my "plant intelligence" video. We know just so little about plants. So often the best we can do is an empirical approach. Try something, see how it works. Try to control all the variables and only change 1, then see how that works. Rince and repeat for the million or so variables and see if we can learn anything at all. But when it comes down to it, we just do our best and try to mimic nature as closely as possible. That's the way to get as close to the mark as we can.
Interesting to hear your thoughts on this, it is a very important topic. I find it almost impossible to whether most garden advice is based on actual facts/research or merely hearsay, especially as a lot of advice is conflicting regarding planting times, pruning, pollination etc.
I am so glad you addressed this and shed some light coming from a scientific perspective. Thank you! Since you mentioned a total sacrifice of nitrogen fixing plants would be most beneficial, I'm wondering if annual native nitrogen fixers are perfect for this job. For example, partridge pea is a nitrogen fixer that's an annual and grows from seed again each year. It also self sows very easily so should be pretty hands off. Bonus that it's native, at least in my area. Keith, I'm curious to hear your opinion about whether this would work as a yearly auto-sacrificial nitrogen-fixing plant. One thing I'm wondering is if it's not ideal for fruit trees to get the flush of nitrogen at the end of the season when the partridge pea would die off since the trees are about to go dormant...
I think its very possible. The only thing that may need to be answered first, is WHEN do the nitrogen nodules swell. If they swell in anticipation of flowering and fruiting, and the plant then uses that nitrogen to grow fruit (most N is used for leaves though), or if the plant uses that N towards its end of life, to ensure fertility for the seeds it drops, then it may change things. In short, I don't know, and there is no evidence that supports it scientifically. However, that also doesn't mean it's not potentially true, because if there is no money in the science, then it won't be done. But that doesn't mean it may not be factual. Long answer for.... I don't know. But it sounds feasible and makes logical sense.
I've this bad habit of questioning everything, regardless of source :) resulting in a constant string of experiments, most of which seeming to confirm the "known facts" - and every once in a while I stumble across a new nuance, which I'm not in a hurry to explain, but rather catalogue under "yet unexplained facts" . Take sunchokes, for example. I cultivate in 2 shadow locations and 1 sunny locations. One shadow location does much better than the other shadow location. The sunny location has mixed results, as well. Next to a great, vibrant plant, I have this stunted, struggling one. Daylilies. After 13 years of neglect, (and thriving), one of the patches shows signs of "rust".. Anyway, my nitrogen fixers of choice are legumes. Yearly and edible, what's not to like? And garlic and chives are my pest control :) Currently working on establishing garlic chives - why is it so difficult? Sea buckthorn - it is the height of the summer - gazpacho should be on the weekly menu - especially if the cucumbers are starting to produce like crazy - a handful of berries will bring it to the next level!!! Savory smoothie, is it not? ------------------------------ Looking at the city with fresh eyes, I can see a lot of trees with sea buckthorn-like foliage, but too tall and rather trees than shrubs - any idea what can they be?
great comment as always, and a great attitude to have in my opinion. For the shrub, I agree it's highly likely either Russian Olive or Autumn Olive, but without a picture it's hard to know. Autumn olive, I did a video on them, so you could find that and compare. Russian Olive is very similar but has beige dusty berries and more of a beige color leaf.
My own thoughts are in a similar space to yours. But I have been interested to read some more recent science on nitrogen fixing bacteria residing in non-photosynthising cells in leaves and stems of plants. Basically the group of "nitrogen fixing" plants may be far broader than traditional permaculture currently realises and explains why some crops outside of those traditionally considered nitrogen fixing (the study looks at hemp) do well in poor soil. Look at a recent study at Rutgers University, "Historical Evidence for Nitrogen- Transfer Endosymbiosis in Non-Photosynthetic Cells of Leaves and Inflorescence Bracts of Angiosperms". Catchy Title. I think the implications may really question a lot of what we have considered the basics of guilds. Although bio-accumulation of matter on the surface of soils is great for so many other reasons that maybe it doesnt matter.
I love your videos, and so appreciate your honesty, and willingness to rethink your plan as you research & find new information (or not)! What do the pups think about the chickens?
They are all nuts around them. Lucy is the best, she sits and watches them kindly. If they freak out and flutter about, she will get excited, but if they don't run and if they stay calm she does too. Harry and Ginny are nutso maniacs. They bark and circle and scratch the cage. They get the chickens all riled up and stressed out. So we are trying to work with them one on one. Sit them out there, hold them and pet them and force them to just watch them next to us, without freaking out. It's going to take some time for sure.
With respect to tap roots, I remember a geology prof explaining the fluctuations of calcium in the soil with the variations in the local water table. Tap roots plants like dandelions compared to grass with a fibrous root system would be at an advantage in times of drought for the collection of such an ion (amongst others). Anecdotal observation of my lawn mower clippings with dandelions amongst them suggest plants whom get this mulch look happier.
Isn't the taproot also a great fallback in a drought? I don't think a comfrey plant, no matter if it's 3-5 feet tall, needs a 50-foot taproot for stability! I expect that its longevity may be assured by access to water deep in the ground.
I am of the same mindset---let me see some data! While not necessarily addressing "tree to tree" nitrogen transfer, this article appears to have studied nitrogen transfer from tree to cereal crop interplantings, using N isotope markers. I've only read the abstract, but what I gather from the study is that "it depends". Its not a single variable that can be controlled. The study suggests that under the right conditions, yes it does occur. I'm still digging for more studies.
I understand it a little differently. N-fixer as example: you chop off thin branches full of leaves (high N material) and mulch a different plant with it, then the nodules in the root zone give a sort of 'food storage/grow juice' bump to the coppiced N-fixer, compensating it back to balance and re-accumulating N for itself for next time. Also the mulching inherently just adds organic matter to support microbial life which is doing a lot of things to make N and other stuff more readily available and with higher storage capacity for excesses from things like animal pee for example.
My key principle is to observe what is functioning in the native ecosystem and enhancing and expanding that. The best think I’ve done for my soil is to buryi the wood, leave the leaves and direct the water.
Confused! I have gardened very successfully for over 40 years and I listened to this and think what hell? Good on u and anyone else who gets this, I don't, I will just grow my food and apparently Mother Nature just takes care of me. 😏
Autumn olive is a nitrogen fixer. The USDA found "Analyses of black walnut tree diameters 13 years after planting showed that interplanting autumn-olive, black locust, and European alder increased walnut tree growtb, but only at certain locations. Interplanting autumn-olive resulted in increases of 56 to 351% at four of five locations and all species resulted in doubled walnut growth on an upland site. The interaction between treatment and location indicates that a fuller understanding of site and nurse species characteristics is needed to obtain the potential benefits of mixed plantings."
I think it‘s great that you look for scientific backing of the things you spread and in doing so encourage us to do the same. Based on my research, I do think that tap roots on certain plants make nutrients available to other plants that plants near the surface might not access. Mineral ions like calcium are dissolved in the water that plants take up over their roots. Calcium has been shown to pass through root tips, including tap roots. Although there are more nutrients in the top soil than in lower layers, if the water flowing in the lower layers manage to dissolve mineral nutrients from rocks they pass over, then these nutrients can be picked up by a tap root as it takes in water. These nutrients are then stored in the root until the plant needs them. The nutrients are not available to other plants until the plant with the tap root dies and the nutrients are made available to the microbiology in the soil at the surface (provided the nutrients have been used to build plant matter above or near the surface. Nutrients that are available in this way need to be ones that can actually be found in the lower layers, like calcium ions.
dandelions are a great case study for this exact phenomenon. I wish more research was done on them and their ability to capture calcium and return it, and exactly how deep they do this from.
Chop and drop is a lot more about feeding the overall soil food web. Obviously compost, especially vermicompost is proven powerful stuff. It’s the byproduct of all the organisms in your food web that you’re feeding and sheltering with chop and drop
There's a few things I would like to clarify: - The benefit of the nitrogen fixers could also be this giant pump of carbohydrates into the soil food web. If the fungal network is supported by these fast carbon pathways, there is more capacity to in turn support the productive species. - There might not be much evidence for where the nutrients are coming from in comfrey and I agree it might just be the feeder roots. But I have certainly seen scientific evidence for the soil around comfrey plants to be higher in plant available nutrients than surrounding areas without comfrey.
100%. This video isn't to debunk nitrogen fixers in general. They still produce root exudates and leaves which drop, both of which taking the nitrogen they use from the air. They absolutely take that nitrogen and put it into the soil. The mechanism for it however is what I take contention with. There is very little to no evidence that chopping them causes dislocation of root nodules, despite many many people claiming that's what happens.
@@CanadianPermacultureLegacy And yet Geoff Lawton has said it in the past and as far as I know, never retracted it. Though he doesn't seem to say that it any more.
Love your videos, especially because of your scientific analysis of everything, i’m the same way. That’s the only way we make progress, as older theories are disapproved or improved. I’ve wondered the same thing about tap rooted plants extracting large amounts of nutrients from what is often poorer quality deeper layers of subsoil, but I also wonder if deep taproot serve another purpose, other than the obvious one of added stability. Wouldn’t deep taproots also allows those plants to access water at much deeper levels and outcompete less blessed plants during times when moisture becomes scarce. What are your thoughts on this?
Yes, and more specifically they provide the pathway itself for water to reach deeper into soils, which then allows life deeper into soils. And when the plant dies (deep taprooted annuals), there is now also organic material deeper in the soils. Very important plants!
The idea that plants share nutrients has been varified scientifically. You can look up the work of Susan Simard on youtube and elsewhere for that. I do very much agree with the gist of what you are saying, and there is always a good reason to be careful with what we say or write as it may be passed down information that has not been varified scientifically. The part about the tap root not being a feeding root is possible but also not varified from my understanding, but your statement that it is all about stability might also not be accurate. Many plants with a deep taproot are doing so because they search for water at greater depths, like many desert trees. It would be interesting to know under what circumstances someone was able to find a comfrey root at 100 foot depth, and what was happening in that area in terms of water issues. I don't write this to naysay what you were on about in this video, because your way of reasoning is very valid and well thought out. Great content as always.
Zero faith in science LOL, just look at germ theory + vaccines BUT your Food-forest speaks for itself....healthy, happy & abundant w Life.
The veg farm, on the other hand, has constant issues w infestation etc. Last wk I spent 2 days adding Nitrogen Fertilizer to all greenhouse plants.
I notice the 🐝🦋🐦s stay on the perimeter of the fields where the Forest & Blackberry bushes are. Enough said
There are good actors and bad actors everywhere, in every field, every niche. Some more than others. And if there is money to be made, the more bad actors come out to swindle and steal.
Some areas that are heavily with predators are things like cryptocurrency, medicine, farming, meat/veg, etc. But that doesn't mean we should throw the baby out with the bathwater and label all science as bad.
Cryptocurrency is a giant scammer party, but that doesn't mean there aren't critical applications (that are green for the planet) that are being developed. Ethereum, nano, these are great examples of world changing technology living in an ecosystem of thieves and bandits.
Sure, when tobacco was being marketed as something all the best athletes use, the science that paid for this wasn't unbiased, and thus was flawed. The meat industry is now doing what the tobacco industry did, and pushing propaganda science. But that ALSO doesn't mean that there isn't accurate unbiased science that is Pro-meat, as well as biased "science" that is anti-meat, funded by groups who hope to sell plant based meats. A big indicator of that is what the anti-meat science uses as it's baseline to compare? Do they use industrial agriculture, which everyone knows is terrible, or Silvopasture and regenerative agriculture? Well, what agenda are they pushing? Etc. The world is rife with scammers and liars and bias and agenda. Where it really gets confusing is that this also doesn't mean that plant based meats isn't potentially an incredibly useful technology, even with the inherent bias!!! What an information maze this is, rife with traps and predators, but sometimes those predators are right! Sometimes they are just predators. That's our crazy world that we have to navigate.
Same goes for many topics. I am very pro-vaccine in general, but I'm also not blind to the fact that where there is money to be made, one should question the research, especially when there is a conflict of interest in the funding of a thing, ajd the profit of the same thing.
I'm certainly not anti vaxx, but I respect people who are, simply because of how muddy those waters are. I'm not anti climate science, or hate climate deniers, because of the same reason.
so instead, in those areas, I try to focus on the unifying facts. For climate science, it's that many resources aren't renewable, such as natural materials, coal oil and gas, and biological ones such as life and diversity. So if we can take actions that remedy those things, but they also help with carbon, then we should do it. For example, taking carbon out of the air is a key factor for climate science, but PUTTING carbon into the soils to build a robust food web of life is CRITICAL for the health of our soil biome. So let's do that. We do that with planting more plants and getting more carbon heavy root exudates into the soil. The only consequence of that action is more trees, cleaner air, cleaner water, more animal habitat.
That's my approach to these areas of bias in science. I appreciate the sentiment of not trusting science, but let's not have zero faith in science, let's have a heavy skeptical eye towards bias, because there is a lotbof good science being done, ajd it's critical that it gets done, to fight against the biased science that corporations push in order to support their industry's continuation and growth. It wss tobacco and oil in the mid century, but its evident in many places now.
The last thing is that the lack of science in an area MAY ONLY indicate a lack of financial incentive to run the science. And if there is a financial incentive to NOT run the science (such as selling fertilizer to farmers) then any science that tries to debunk that, is going to have armies of propaganda science to fight against. So the lack of evidence for something doesn't always mean anything. Failure to prove something isn't proof of failure... especially if the journey to do so isn't even taken.
I'm going to pin this comment. I know I went off on a massive tangent here, but the whole discussion is directly centered on the heart of this video... which is to seek information, but also understand that the waters are murky at times, and money muddies all things.
@@CanadianPermacultureLegacy Well said, thank you!
@@CanadianPermacultureLegacy Well said! I used to be really into science as a kid and still am infinitely curious about how things work. But lately I have been more and more skeptical of mainstream science once I started to follow the money trail. There is good work being done but it is often muddied by massive financial backing by those to stand to gain from a particular outcome. This leads to cherry picking data and spinning of the results by so called "experts".
The great thing about gardening is it's not that hard to do our own backyard science. Now it may not be super clinical and we may be introducing our own biases but at least we can see the results for ourselves and come to our own conclusions.
Stay curious!
@@CanadianPermacultureLegacy this is the approach I like to try and take with these things as well. Sometimes digging through the bias is exhausting though lol
What’s wrong with germ theory?
Grad student studying rhizobia (the bacteria in root nodules) here with some clarifications!
Root nodules are not really nitrogen storage organs, instead they just act as the housing unit for the bacteria. Rhizobia while in nodules are basically factories. Their existence is devoted to converting N2 to NH3, and this produces a lot of bioavailable nitrogen… but the plant also needs a lot of nitrogen and nitrogen is a very common limiting nutrient in soils. Nitrogen is needed to produce essentially all biomass because there’s a nitrogen in every amino acid which makes up every protein, which makes up every cell in every plant.
This nitrogen demand, means that there isn’t really any nitrogen storages, it’s all just constantly being used to produce more plant. So even if the nodules did dissociate from the roots, it’s just releasing a little plant tissue and a bunch of rhizobia (not a bad thing, just not like a nitrogen tsunami washing over the surrounding soils).
What I’m trying to say is that all parts of the plant are mostly equal if in terms of nitrogen density, so chopping and dropping leaves would be reasonably similar to chopping the same amount of roots and mulching with that (just looking at nitrogen anyway).
All that being said. N-fixers take tons of N from the air instead of from the soil. So they are introducing new Nitrogen to your system at the end of the day. That nitrogen gets sequestered into the roots, leaves, and dead biomass of your system.
IDK anything about Taproots lol.
TLDR: Leaves/stems have PLENTY of nitrogen, and those leaves were made from nitrogen that was newly added to your system thanks to the ability of N-fixers who use nitrogen from the air instead of the soil.
Great video, love the transparency and thanks for all you do!
It looks like permaculture books focus too much on the nodules themselves. I think the overall strategy in the video remains solid though. N fixers mostly provide for themselves. When we just leave them be, they drop leaves, and a lot of that N came from the air. If we chop them, then drop the chopped material, a lot of that N came from the air. At the same time, if the roots die back (seems still to be contentious if they just shrink, or get disassociated), but none the less, even if the nodules themselves aren't a slow release fertilizer pellet, it's still organic material high in N, a lot of which cake from the air.
Is that your understanding of it? Anything I have wrong there? I want to make sure my mental model is correct, because I never formally studied this stuff in university. I appreciate your comment so much!
Exactly, nodules aren’t slow release N fertilizer granules, but they are still rich in N (as is the rest of the plant).
Another note: rhizobia and N-fixing plants only form that symbiosis when the plant is limited by nitrogen… this means if a n-fixer is happy and healthy in in a N-rich patch of soil, it will not recruit rhizobia to form nodules and fix nitrogen.
This means that N-fixers are much more valuable to a nitrogen poor system like a corn field than a lush established climax forest ecosystem.
Thanks for responding - your community engagement is top notch!
That last part is very interesting, ajd I've noticed it a lot. I've been digging up a lot of my wilder varieties of seabuckthorn, and I'm noting a huge disparity in nitrogen nodules. Sides of hills and more neglected areas have much more nodules on the roots than areas in my main strip where I tend to focus more attention, more chop and drop, more mulch top upside, and more yellow gold applications around fruit trees. It makes sense and echoes what I'm seeing here.
Thanks so much for the comments. I love learning things from you all. Everyone is an expert in something and can teach you something. ❤️
Thanks for sharing.
"When I read something and realize I've been parroting something that may have no scientific backing, I think it's my due diligence to respond back to you guys..." God bless you for this! Too many people let pride get in the way of truth. If everyone was so willing to jettison unsupported beliefs, what a better world we could make!
Thanks!
A core problem with "there's no scientific evidence" as an argument is that any such research is only done if a researcher can get funding and the vast majority of funding is tied to someone making money from the results.
This is 100% true. Failure to provide proof, isn't proof of failure. Especially when there isn't even an attempt to do so, because there is no financial reason to. And even worse, where there IS a financial reason to maintain the status quo.
@@CanadianPermacultureLegacy this. Ernst Gotsch.
A place to look would be old Soviet records. Don't get me wrong, the Soviet Union was awful for a lot of reasons, but I'm the early days their research really was looking at how to boost food productivity and such for the mass of people. I'm pro Socialism and VERY anti Soviet. But they may have some good stuff.
@@d.w.stratton4078 The information about soviet union comes to us from the same bunch of people who promote vaccines, drugs, monoculture and the like. Its about 90% false, and it would blow peoples minds to discover what actually happened.
@@CanadianPermacultureLegacy Some scientists move past this hurdle and pay for it themselves. I have massive respect for those people. Scientific evidence is worth more than gold.
Very good video. Thank you. Anyone saying "I have said a thing and I can not validate the thing: here's what I know now" is really important.
It's a huge part of science for sure.
I think the deep tap root also has another role. Once the plant ends its life cycle, the tap root dies off, leaving a "tunnel" in the ground, that will help with water infiltration, aeration of your soil, and also roots of other plants and fungi might use it to travel down. This way by having tap roots growing and dying in your soil, you might be accelerating the ability to create a thicker top soil and sub soil layer.
In our fields we have found roots of clover going over 1.5 meters deep, that only happens if the soil is loose enough and alive enough, such that it can penatrate. When starting with very young soil, taproots might play an important role in achieving that. Also look at the work of Gabe Brown, who uses plants with tap roots to "drill" through compaction layers, such that other plants might utilize these pathways when the taproots die back, creating a thicker topsoil layer over time.
We have a lot to think about and to learn, but luckily if we do good thinks for wrong reasons, it still works, nature is strong :-)
for sure.
THIS is why I continue to follow you and your channel. Ethical transparency👍🏻
That means a lot :)
thank you for your drive to ask questions and see for yourself, and your way to present that information to us. I find this a lot more helpful then i know everything approach.
I think this is the only way to have good communication, good debates and ultimately, good solutions for our problems.
this video is my cup of tea.
This just came up in my feed. Since you published this, Helen Atthowe published The Ecological Farm, a science-based book on ecological farming. It's right up your alley. One of the big points she makes is how much of the nitrogen in leaves chopped and dropped on the soil surface actually volatilizes as a gas. If applied to the surface, some nitrogen does end up mineralized in the so but to maximize the effectiveness of chop and drop for nitrogen retention, it needs to be somewhat mixed into the top layer of the soil. Also, if you hit google scholar, there is an interesting 2021 SARE doc on dynamic accumulators that has more information than I've seen.
Thanks for those threads to pull on!!
Did the same research myself a while ago (science nerd med tech here) and came to the same conclusions. Most of my perennials have a food purpose - berries or fruit - but I do have lots of comfrey that I chop and drop to add nutrition to the soil. I plant peas and beans with some of my perennials as well as in my annual beds and chop them off at ground level so the roots will break down over winter as the upper parts break down after I scatter them over the bed and/or put them in my compost bin. My comfrey is chopped and dropped and also added to compost. Do appreciate the deep tap-rooted annual plants for their ability to break through our hard soil - and then break down in the soil over winter then the plants die. To me the most important thing is to incorporate a lot of diversity and put all that stuff back into the ground, one way or the other.
Plant leaves and stems have nitrogen in them. If you chop pieces off a nitrogen fixer and drop them next to another plant, you're supplying nitrogen to the second plant without depleting the soil around the first. Even without the nitrogen fixer cutting off root nodules, that's still something.
100%
Yes but it takes quite a while before its available. My thought is put it in the compost, or consistently use it as mulch.
Where do plants get nitrogen? Air or soil? If from the soil then it's depleting it? If you chop it and drop it elsewhere it's being relocated.
@@juxtageist plants that are nitrogen fixers (like beans) get it from the air. Other plants (like tomatoes) get it from the soil.
Oh goodness gracious. You are addressing some of my pet peeves. I’ll start with comfrey, it’s tap root and chop and drop benefits. The tap root is not only a stabilizer, it is a channel for air and water deep into the soil. A plant doesn’t have to delve deeply into the subsurface of the soil in order to successfully access multiple nutrients. The stems and leaves may only be from the top 5-8” but so what? The leaves are still chock full of diverse nutrients.
One of the main benefits of chop and drop of comfrey is the rate of decomposition. It’s extremely fast. The plant is engineered to return all of that nutrition to its own root system precisely because its growth rate is so high during the season. So if I cut back my plants once the stems droop to the ground, chop up some of them around my apple trees as well as the comfrey plants themselves I am helping the comfrey to share its wealth. If deer and raccoons and wild pigs were allowed to roam through my food forest they would spread these materials for me. I’m just acting like a wild animal in mother nature’s scheme.
As for nitrogen fixers each plant benefits from its own storage system while it is alive. Other plants close by don’t have to share the nitrogen that has been delivered by other systems. Once the plant is dead it’s storage load does become available to other organisms. But killing a nitrogen fixing tree to feed another non-nitrogen fixing tree is - well - stupid. Rain carries a higher nitrogen load that a root systems’ storage capacity. By the time other plants can access those storage nodes the rain would have provided for their needs. Annual herbaceous plants are another story. Once the clover dies back in late autumn the winter seasonal plants can take those nutrients to help them deal with severe conditions.
Back to the nitrogen fixing trees. These are pioneer trees. They show up in areas that are transitioning from grassland, scrubland to forest. There isn’t a vast web of deep root systems to take advantage of. Conditions may be arid until the evapotranspiration systems can be re-established so rain may not be a reliable source of nitrogen. In this case the pioneer trees are especially designed to thrive whereas other more valuable trees may not do well, without drawing on the nitrogen stored in the soil/water/salt/plant material. They are usually fast growing and short lived. They develop root highways for future plants, break up hard pan soils and replace carbon quickly while leaf drop build top soil and slows erosion. Around here alders are known as widow makers because their branches don’t hold up well to not-very-strong winds. They are dropping their carbon load regularly. Their photosynthetic produce is different from grasses, weeds, shrub and vine layers so are also tailoring the soil life to support longer lived more valuable forest. And I’m not talking about more valuable in terms of how much a lumber baron can rape the land for. I’m talking about long term healthy sustainable forest tailored by Mother Nature.
I would love to site the original research but the sources are varied. I can tell you little of it comes from the US where I live. Mostly from the UK and Scandinavia is what I remember. I can tell you that the agriscience department at Eugene OR has corroborated some of the research’s validity.
Man, so many comments I want to pin. This is just such a fantastic comment, as always.
If one was a skeptic, but still open minded, not enough to take a youtube comment as evidence (absolutely no offence meant to you or others) where would one find the information that you speak of? eg; " The plant is engineered to return all of that nutrition to its own root system precisely because its growth rate is so high during the season" Is there somewhere I can confirm this in order to help and/or teach others?
Hi there. What a wealth of info. Would be terrific if you were to create 5 minute content videos like this response, as you walk thru your forest. Some info might be applicable to others more or less but the thinking process is what is common to everyone. 🙏🏼
I enjoy and endorse this comment!❤🙂
Thanks for the honesty. I suppose I practice permaculture and no dig in a loose form. However I get put off by the sort of fanatical zeal that sometimes comes across from permaculturists on UA-cam. I'm glad I came across this video because I hope it is the start of more balanced approach. I feel that more scientific study will improve what we're doing. At the same time I think we should go ahead and keep doing what we find works for us. Chop and drop has proven results for me, in my garden. I haven't planted nitrogen fixing trees because there are aren't any that will do well here that I want to grow, and I haven't been convinced of the benefit. I find that any healthy plant improves the soil so I don't feel I need to spend resources on nitrogen fixing trees. I am interested in looking into increasing the native nitrogen fixing plants in my garden.
Hell yes. This is my channel. I like thinking on what the old wives' tales were, and if they were accurate given what we've learned since. I'd like to think they're usually right but maybe for the wrong reasons or slightly right but didn't know about the better options the internet, science, and time has shared since. Great video.
When I was in Horticultural College, we were taught different types of digging, one of them being double digging. During this process you dig to a depth of 2 spits down. However, my lecturers always said, never mix topsoil with subsoil, because subsoil is 'nutrient-poor'
... which is interesting, because if deep tap-rooted plants are growing roots way down into the subsoil (and they are, because I've plenty of experience digging down to hoick out persistent weeds), according to my lecturers, they can't be bringing up much nutrition from a layer that's known to be nutrient-poor.
So my guess is - it's going to work if you're lucky enough to have really deep, rich soils. Since many of us don't (my soil being very thin and rocky across much of my garden), deep tap roots are a waste of time for conveying nutrients.
That said, I do grow a few types of chop and drop around the garden because I am very keen to 'build' topsoil -
Comfrey, Oriental Poppies, Ferns (inc Bracken, which makes a lovely dark, airy compost), the highly regenerative Heracleum sphondylium, nettles, lots of different types of vetch, and even the dreaded Rosebay Willow herb has donated a great deal to soil building.
I don't remove grass before planting either. Lots of people criticise me for this, but I garden on a steep slope and if I was to smother the grass and kill it off, the soil will just wash away in the Autumn rains. Grass is a pain to control, but it's the best thing for holding the soil structure together.
You’re extremely knowledgeable! What are your thoughts on using Corsican mint for a ground cover in a small space?
Fantastic comment as always Debbie
Yeah but they atract funghi down there
So my understanding is that taproots are not grabbing "nutrients" from deeper sources but minerals. You're absolutely right about topsoil being more fertile, but the different root depth is supposed to draw up minerals not accessible to shallower roots.
The Holistic Orchard by Michael Phillips is my source but it's not a scientific text so no cited studies from him.
@@dragonfireink139 wouldn't those minerals also be present in the topsoil? Clay is mainly made of silicates, magnesium and calcium - those aren't used in significant quantities by plants, unlike N, K, P
I thought chop and drop was just a slower way to compost in place while acting as a mulch. Like how nature would do it but where we want it.
Isn't the point of nitrogen fixers to harness their dieback to feed nitrogen and not the plant itself? The dead matter itself feeds nitrogen and the barest line for nitrogen fixers is they can survive the repeated dieback. I'm not sure if it's just what I've grown but have definitely had root die back in my containers after pruning for clones. It also stimulated rhizome production.
The deep tap root stuff, I have no clue about but you have proven it makes a great root wall to make a border.\
"When someone's telling you something challenge their background and qualifications for telling you that thing"
I'm afraid I'm going to need your background and qualifications for telling me that.
Great comment! LOL at the end. Checkmate. Paradox found.
I love the openness and honesty here! And also the acknowledgment that just because there's no science behind something, doesn't mean that it's not helpful, we just don't know the mechanism involved. Yet. There is very little else that you could say or do that would more firmly confirm for me that I made the right decision in subscribing to your channel!
Thanks!
I think so much of permaculture is really based on observational data because we just don't have good research on it. So it makes perfect sense to me that the practice itself is likely sound but the justifications they offer are inaccurate. Medicine still works that way, often. When I took psychopharmacology (it's been a decade, so this could be irrelevant by now), we still had no idea what the mechanism of action was for lithium, but that doesn't mean doctors don't still prescribe it.
Thank you for being a scientific resource and voice in permaculture! I've struggled with exactly this - feeling pulled between the two minds science and this innovative making it up as we go kind of practice. But I still feel much better about this model than more traditional gardening, even the organic versions. I really appreciated this video!
Indeed it's a great point. I touched on it in a few replies to comments, but the absence of research isn't proof to the contrary, it's just absence of proof.
Nice! Happy to see this kind of thinking promoted here.
I had a few small comments of things that went through my mind while watching.
Nitrogen fixing is not a vestigial function I would assume, so the plants are doing it because they need nitrogen. For example, the nitrogen in bean plants is used to actually grow beans. Amino acids in sea buckthorn come from nitrogen as well I believe? Sacrificial plants would need to be sacrificed at a stage in which they have stored a lot but haven't yet used it I would imagine.
Chop and drop is good because the leaves are not only carbon created from solar panels like you mention, but it's also the vitamins and minerals that are in a plant available form. The soil food web not only feeds off exudates but also the greens like things that are chopped. When predators like nematodes eat that bacteria they die, then those minerals are available to the plant. Otherwise the bacteria and fungus would be presumably spending more energy harvesting from rocks, soil, minerals instead (or maybe whole other species do that more likely).
It's also free mulch and additional habitats for insects. Anecdotally, after I mulched my exposed sunchokes which kept wilting on the heat, not only did they not wilt anymore, but spiderwebs started to cover the whole surface between them.
Less importing of organic material from other places like chip drops or Home Depot.
Taproots are also for water access as well, yes? Same argument for nitrogen then where it's not using as much of the higher water table and it's available for other plants nearby. I imagine that means chopping the leaves provides moisture up top from down below? But also the physical act of drilling a taproot down creates a pathway for things to travel upon which it might not otherwise have the opportunity to. Bugs and other soil life can move both up AND down. And when it finally dies, that rotted taproot is a benefit on its own just like any roots, except across many different soil layers.
Chop and drop is still always going to be like composting, just the "unmanaged" way nature does it instead of in piles like we do. You need to take weeds and trim stuff anyway and it's either free mulch at the minimum or a compost ingredient in the bin or on the ground.
Thanks again for doing what you do! Any thoughts on how to address things like this you've previously said in old videos for people just seeing them for the first time before this video?
Amazing comment, all of it. I agree with it all. So many benefits of having robust root systems in the ground. Chopping and dropping, even if they don't actually disassociate the root tissue, and they only shrink it, that's still going to function as more low-resistance water pathways to get water deep, which likely also causes a microbiology explosion, etc.
For the last question, the only way would be to take the video down, but what I can do is recommend this one at the end of those ones. It's likely that some of these comments are pervasive in most of my earlier videos, and there's so much good content in those that I think I'd be throwing the baby out with the bathwater to eradicate any error by deleting videos. It's definitely a tough balance.
I will try to mention these things in future videos.
One other thing, I find that older videos get almost no views after the first month or so. I think that's just how people devour youtube content. It's also for that same reason that I'm going to focus on "redo-ing" many topics each year, or every 2 years. So many new viewers for example will never run into some of the more important videos I've done, just because they are searching through so many of them, and the habit is to watch the newer stuff.
@@CanadianPermacultureLegacy if I had to guess, I would postulate that the drop off is that your channel primarily seems to be updates on your garden and progress of this or that. Your most watched videos seem to have concise titles conveying a single topic. The other ones are often more ethereal, and meandering around the garden talking about several points as they come up. Those won't trigger keywords and be searched for often. Nobody is specifically looking for a bunch of people's "updates on chickens". That's not to say they won't enjoy it if they came across it though!
I particularly enjoy these because it's fun to see everything in context, but the titles and content probably don't trigger the algorithm to show those kinds of videos to people because it's hard to draw a line between those and other kinds of videos on UA-cam.
Whereas "Starting a food forest? My top 6 berries" or whatnot connects to everyone beginning to look into food forests. "An update on the chickens" vs. "3 things I learned after starting a chicken coop" shows maybe how to connect into that more?
Anyway, what are your goals? Do you want to monetize? Do you like expressing yourself? I enjoy the updates because they are so relevant and timely, being in a similar climate myself. I don't use your channel for "how to's" I use it precisely for the educational meanderings and that you have a good presence on camera.
Playing the algorithm game and "top 3 things" and "5 mistakes I made..." exclusively is exhausting and clickbaity if that's all a channel is IMHO. And the incentives might not be aligned with your intended goals here - you'll have to decide.
Edible Acres seems to have struck a nice balance though. Many of their titles are very concise despite always having a bit of meandering as well.
Neither of you are the flashy "top X" gardening channels that are annoying which you speak of, where sometimes they don't back up their claims with evidence.
Anyway, I watch 90% of your stuff so I don't have any problems myself 😋
Yeah great comment. I've thought a lot about that. If I want to min max and grow as fast as possible, the best way is with "top 10 plants yoy should grow" videos. Or "Walmart hates him, this guy is growing all his own food for free", or similarly stupid things. But I don't like that kind of thing, even if it works, so it's just not me.
Then there is the topic based videos. Sometimes I get a hankering to do those, or a activism style video. These take substantially more time to storyboard, film, and edit. 10x more. They are fun to do, and I enjoy making the odd video that is more highly edited. I think its also a good way to bring in new people.
But my favorite videos are when I go out in the morning and just walk the land, see something neat, get an idea, and start meandering and discussing. I find them very therapeutic. I also find myself learning more about my land by observing, filming, thinking about what I'm filming, learning from it, etc.
Long answer that my focus is definitely not on channel growth, and absolutely not at the cost of being annoying. I know it works. I just hate it so I'm not going to do it. I may do the odd one here and there as a test, so if you see an annoying face reaction thumbnail with a clickbaity title, that's probably me running an experiment, and it will be very infrequent.
My main goal is to have fun doing this, because as soon as I don't, I will stop, because the money quite frankly sucks LOL.
Very refreshing, great video! I love that you are honest, inquisitive, and straightforward.
So glad I found your channel.
My hubby and I are just getting started in permaculture. Very helpful!
Thank you kindly 🙏 ☺️
I'm so glad I finally watched this video. I had been wondering about that very thing even through I heard it from nearly everyone. I've not had time to do tons of research, so thank you for that, too.
I plan to have a small "food forest" on my second property. I'm now working on reducing invasives, replacing them with "free growers" that don't need much attention, researching native plants, deciding which ones I and extended family will be more likely to actually use, and planning layout, etc.
Realistically the plantings won't begin for a few years when I can actually move there. The part of it that is not forested is just VA red clay so needs all the help it can get. The past few years I've let the grasses grow & mow them occasionally so I hope that has helped somewhat. Now I will make an effort to plant at least the areas where I plan to garden with annual and biannual plants to let their natural cycles improve the soil as well as support pollinators and wildlife.
There are already some wonderful volunteer raspberries that produce a really nice crop. I've actually managed to maintain them pretty well. It's easy to take a gallon in a 20 minute pick session.
I wish some birds would be nice enough to plant some blueberries for me, too!
Building soil is a very good cause! Great job! Keep sharing your experiences… cheers from Argentina
You too! ❤️
So nice to hear someone step back from the regurgitating tendency. It's definitely a difficult tendency to break. Like most my initial knee jerk reaction was what you are going to say nitrogen fixers don't improve soils, but I stuck with it and I have to agree on both accounts. I can't say I have ever seen evidence that they feed nitrogen back into the soil except in situation where they are culled completely. I have seen some limited transfer via mycorrhiza. Also I completely agree most people completely misunderstand what the purpose of a tap root is. This is extremely common in tree growing communities, people often believe that the tree dies if the taproot is severed, but that is completely false. It's done all the time in the nursery industry on purpose.
Definitely gained a subscriber as a result of your honesty. Keep up the good work.
Exactly. N fixers have a huge part to play in a system. Even if all they do is grow leaves using N from the air instead of the soil, that N is returned in the fall during leaf drop. It may not be "fixing" nitrogen in the traditional sense of rhizobium bacteria, but they are still improving nitrogen (and carbon!!) in the soils by dropping leaves which were mostly created from thin air and some rain.
A suggested process from soils classes is that the soil fungi tap the roots on both a nitrogen fixer and the other plant and trade certain materials from both plants back and forth acting as a small trucking company so the plants don't have to die off to share their nitrogen. That the plant release certain exudates to trigger certain fungi to bring in iron or phosphorus etc. And nitrogen is on that list. So if nitrogen can be shared even at low levels it has value. And this would seem to be fairly likely as the gains from aerobic fungi and compost teas don't make real sense unless this is at least partially true. Still learning here too.
Now as for deep root feeders even if 99.9% of stuff comes from the top 4 inches you are still gaining 0.1% from deeper. But the other thing you gain is a pipeline feeding and carrying soil fungus deeper and building soil carbon and therefore water holding capacity, nurtrient banks and making the soil more oxygen permiable. So now say the soil is good enough 6 inches down to support that web of life. Now you have 50% more available nutrients for plants.
Great points, 100% agree.
This is all very interesting and I'm so happy you're uncomfortable with just parroting what everyone else is saying! I'd love for you to take a look at tomato pruning. SO many experts say you get more tomatoes if you remove the suckers and now they're pushing removing a lot of the lower leaves, too. My gut says the extra foliage supports more nutrients for the plant and deeper, more extensive root systems that should make the resulting tomatoes from the bushier more natural plants have more flavor and nutrients. I'm tempted to get a brix meter and try some each way to compare the results but I don't have a UA-cam channel to spread the results. One thing I was thinking about your nitrogen fixing discussion, tho, was the role of mycorhizzal fungi and whether they set up a network to share the excess nitrogen with surrounding plants. Stephen Harrod Buhner and Paul Staments in some book or other mentioned that it can take 10-15 years for some parts of the network to develop, so a lab study couldn't reflect what would happen in an actual food forest. So again, maybe something like a brix test would be more useful in testing in the field whether a benefit is happening or not.
Great comment. I'm nit sure I have the time this year to do the experiments...I know I don't. But I may look into it in future years.
The mushrooms can definitely transfer nutrients, which is one of the main reasons we mulch with woodchips.
Not sure in what talks but John kempf has mentioned this sort of thing. Healthier plants get more efficient photosynthesis so don't remove leaves. And his podcast episode with Greg pennyroyal touches on a moment about a similar concept with grapes in viticulture as its also a common practice to stress the plant for a "better" harvest. Forgive me, I think he kind of sprinkles it into a lot but he's plant health focused so it's his mindset.
I saw this at just the right time!! As always, your videos and approach to building a sustainable food forest has been truly inspirational!! My brand new FoodForest exists because of your enthusiasm and knowledge offered.
😀
Subscribed to the channel. Watched some videos and i have to say this is the first down to earth food forest channel i have seen. Most plant on buckets and call it a forest.
Welcome aboard!
Thank you for your deep dives into these topics, There are a lot of channels talking about them, but not so many doing it at this level. I'm happy to get the information from you, even though this isn't the field you went to school for. It's better that we learn to evaluate information based on the information itself. We're smart enough, and experts are often wrong.
Yeah exactly. At the very least people know about it and can go digging for more info themselves.
I like that you are challenging these statements that are parrotted by so many people. One thing that would be worth discussing on the topic of nitogen fixers would be annual (short cycle) cover crops like fava (broad) beans and whether cutting them down before they flower/produce beans is effective in adding net nitrogen to the soil for other plants (versus them just being less needy with nitrogen than other plants). It is similar to your lupine example, but on a shorter time scale, albeit requiring more intervention than a natural lupine system..
I think this is the most likely example of N fixers working, simply because of how industrial agriculture tills crops like these under.
Thank you this will help immensely! The world needs more education on top of their experiences!
I'm an engineer as well. My aptitude is also mechanical but my particular strength is the ability to see what is happening, understand what is really going on and adjust the process to be more efficient and productive.
My limited experience is with beans and peas. It kind of evolved in my head that they really don't build nitrogen for anything but themselves. I came across something the other day that said the nitrogen (in a fixed form) exudes from the nodules into the soil. I have no idea how true that is. However, it came to me that the store of nitrogen by the bacteria might be used when the plant is flowering and fruiting. this makes sense to me. So after you pick the beans and peas, maybe there isn't as much in the roots when the plant is cut as we might think. I have been using fava beans to fix nitrogen, then cut them just as they begin to flower. The biomass is composted and the roots are left to decompose and release the nitrogen. Now it's in the soil in a form useful to other plants. The "green" of a plant is also full of nitrogen and available to bacteria during composting. If the biomass is dried, the nitrogen is NOT there for the composting bacteria. When peas are finished I pull them and plant the next crop of whatever. The roots don't seem to have very many nodules on them. MY conclusion is, even though the bacteria might still be there, the plant was taking everything to make fruit.
As you pointed out, I have no basis except my own observations. All I can say is... it works the way I'm doing it. And producing FOOD is going to more important than ever soon. Real soon.
This is also what I'm thinking, but as you said, I haven't any proof either, other than analecdotal evidence scattered here and there when pulling a plant. But no controlled experiment, and honestly, no time to actually run one. It would be nice if more research was done on this.
Great analysis. I appreciate your scientific approach to each subject. It is the faithful application of the scientific method that tends over time to lead us closer to the truth. With any common practice which has stood the test of time there are three possibilities: it works for the reason they think it works, or it works but for a different reason, or it doesn't work.
Third year of no external imports to my garden.
I soil tested my bed after I pulled my potatoes and onions last year, kinda low in nitrogen.
After harvesting, I planted some clover. Never flowered before going into winter. This spring I terminated the clover via solarization. Note, I used a pitchfork to loosen the soil, heavy load of snow this winter a bit of compaction and direct planted into the soil.
I know by solarizing, I wiped out a lot of biology, I placed a handful of home grown vermicompost into each potato hole and top dressed the rows of onions after planting. I then covered both beds with aged straw to protect the soil. I normally use shredded leaves but 2 years ago the jumping worms turned my soil into garbage, another story.
In your opinion, was this the best course of action with a clover cover crop, and would hairy vetch be easier to manage.
New subscriber! Dr Ingham changed the way I garden, wish I could afford her course. I did get a microscope.
Stay Well!!!
One other method without having the completely kill is to use Geoff Lawton's strategy and take a long spade and cut around the root ball to disassociate the nodules from the main root. Leaving the plant or tree intact ready to grow the next season
Love the skepticism of the info out there. As a scientist myself, I feel the same way about the many, many unsubstantiated claims out there.
Adam from Learn Your Land will show specific research papers in his videos. I think that would be pretty cool if you also did that.
I really appreciate hearing your thoughts...Thank you for taking time to share.
Thank you for making nice and informative videos. I'm from Finland and it's nice to have a Canadian channel with at least somewhat comparable suit of plants that can grow.
Thanks for watching!
Your channel is fantastic. I love that you have done so much research on these claims and then share it with us. Thank you for being so honest. 🇨🇦🐝
Thanks Lyn 😊
Much respect for researching and correcting previous info you shared that you now realize lacks scientific evidence. Very interesting post. Thank you.
This is why I like your channel - EVIDENCE! While I love many of the ideals of permaculture, some of the claims are aspirational
I prefer to use the term biomass accumulation. Different plants contain different mineral ratio. I plant lemongrass, Vetiver and Mexican marigold in sandy, unfertile soil and they do great. I chop and use it as mulch while adding biomass or add it to my compost pile.
Love this video, I definitely just accepted these ideas because I had heard them so often. It's a known weakness that people are more likely to accept things as true the more often they've heard them repeated, so thanks for reminding me to challenge that.
I don't know why UA-cam hasn't been showing me your new videos as much lately, but this one just came on my feed. Very odd. But this video is the very reason why I love your channel - you are willing to own your own voice and dig deeper. I don't know much about science, but we all seem to walk around "parroting" as you said, without thinking twice about our own real knowledge on the topic.
For me, the biggest garden lesson I learned last year from a channel called Agroforesty Academy, is that eucalyptus has a bad rap that they don't deserve. I am in So Cal where eucalyptus grow like weeds. Everyone in the gardening community here will tell you that "nothing grows under eucalyptus". But the truth is that the trees grow in very poor soil where nothing else is growing...if you heal that soil just like any other location in your yard, they absolutely will grow things under them & are a fantastic source for fast growing mulch!
I have 3 massive eucalyptus on my property, all of which now have things growing under them (including veggies, wildflowers, natives, succulents, etc!) because I have made the effort to TRY...because I pushed to learn more and knocked down a myth. I will be cutting them shorter soon just so I have better access to their canopy for regular chop & drop/mulch.
Sorry for the book...just agreeing that it is SO important to do your own research for your own situation! Thanks for all your efforts.
That's such a common thing too. I love this comment of yours. The hatred on so many nitrogen fixing trees (many many of them are on invasive lists of conservation authorities) is similar. They are "invasive" in poor soils, because they can get Nitrogen from the air. So when humans cut down forests to build subdivisions and highways, and these pioneers dominate the new disturbed dead soils, they are labeled as invasive.
They aren't invasive, they just dominate their niche. As the soil builds from their own leaf drop each season, their niche slowly disappears and other plants now will outcompete THEM.
Often humans have such a short time span that we don't see these longer term implications.
I've been skeptical on the nitrogen fixers as well. Thanks for clarifying your position.
Keith, Great video and there's probably some sort of symbiotic benefit among various plants living together. Lots of complexity in mother nature and we probably will never completely understand it all.
so so true.
I enjoyed this video. It is refreshing to see you challenge some of your own ideas! I have a few thoughts that don't necessarily challenge what you say but are meant to add some context:
1. I am in favour of scientific research but in doing a great deal of reading in agricultural research, have come to realize that a great deal of science does not deal with whole systems but just with a few isolated variables. You illustrated that brilliantly about nitrogen fixers and whether or not they make nitrogen available to other plans. A scientist might try researching for that one variable (nitrogen made available) but miss the contribution of that plant to the whole system (carbon through root exudates etc.) I am encouraged to see that a new generation of scientific researchers is coming up in universities that is working with actual farmers in a variety of settings and are trying to look at the big picture of soil health over a number of years rather than focussing on small trial plots on a research farm.
2. Do not tap roots also create a great deal of drought resistance? When almost our whole lawn is brown, the dandelions (and some of the legumes I've been adding) are still green. I understand that to be because they are bringing up water from deeper in the soil. I have been adding comfrey to our berry and fruit tree area and am amazed to see how it can flourish in the heat of summer when the surface is getting dry. That alone adds immensely to the soil as it continually grows, providing organic matter that can be chopped and dropped where needed.
3. Tap roots also play a role in breaking through hard clay soil. Many regenerative farmers include things like daikon radishes in their cover crops to break up old hard pans. I am happy to see the comfrey flourishing in our hard clay soil.
4. My understanding of pastures (and that may not be true of things like sea buckthorn) is that if more than 50% of the growth is removed through grazing, some of the roots die. If more is taken, more roots die back.
Keep up the good work!
All fantastic points. #2 is especially important, because the tap root not only accesses the water deeper, but also provides the low resistance pathway to allow it to actually get down there.
A thought experiment on nitrogen fixers:
Suppose you have a nitrogen fixing plant, to my knowledge there are only two ways this plant can get nitrogen.
1) From the air
2) From the soil
When you chop and drop this plant, you're adding whatever nitrogen was accumulated in the leaves, stalk, etc back into the soil web. However, some of this nitrogen is lost during decomposition as off gassing.
I would assume that whether nitrogen is actually added to the soil would be dependent on what % of nitrogen in the plant mass was attributable to 1 above, and whether more or less nitrogen than this was lost during decomposition. Basically you're just trying to find the balance of nitrogen gained freely (from air) and nitrogen lost (from decomposition)
It seems to me you don't actually need to disassociate the roots to free the nodules themselves, let the nodules feed the leaves and the stalks and then use them as green manure.
Thought experiment 2:
To think of this in another way imagine you have two cover plants, one a nitrogen fixer A, and one that's not B.
Plant A hypothetically should outgrow B in nitrogen poor soils. When you chop and drop both, there should be more of mass A dropped than of B, as it's a larger plant. If you take the difference in mass, and then find the nitrogen associated to this extra mass, you should theoretically have a rough idea of how much extra nitrogen you've added to the soil via the nitrogen fixer. If there's more of this nitrogen by weight than the entirety of the nitrogen lost by plant A in decomposition then you'd be adding nitrogen to the soil via chopping and dropping.
For sure. This is the main reason why I think they are still worth growing.
This video wasn't so much about mythbusting if nitrogen fixers are useful, but just Mythbusting the claims that are made that once planted they pump nitrogen to surrounding plants, which I've heard in permaculture so many times.
I think a big part of N fixers is the fact that there bringing in organic matter from the air and are “pioneer” plants meaning they can settle in very poor conditions, and then slowly making it suitable for other plants until one day it’s an Amazon forest!
they're* and nitrogen gas is inorganic not organic.
Glad someone is addressing this. I always wondered if the fungi could fix nitrogen from digesting regular plants, or how much nitrogen is fixed in the guts of bugs that eat the plants, or how deep below the active layer the soil fungi can reach to extract minerals from rocks. I do know that some plant taproots do extract water from deep below the surface (like faidherbia albida) so that may also bring other nutrients up.
Thanks for your honesty.
Much respect for doing this video. Nice work as usual. Thanks!
Thanks 😊
Old school farmers around here still do a season of red clover, which I seeded heavily in my backyard; this year - this week in fact - I decided to scatter lupins around, too.
Mythbusting would be awesome as a regular segment! You could voiceover the view of the pond.
Just on the subject of taproots, those do bring water to the surface, allowing for a huge amount of carbon fixation every season. I grow bullthistle just for the biochar (and because it brings in the sweet little goldfinches haha).
Thanks for addressing a major peeve! It always disappoints me when someone I consider an authority spouts some clichéd nonsense without a second of critical attention. But I do hear marigolds flowers will give your chicken eggs a gorgeous colour!
Dr Christine Jones is well respected in this field. There is a lot of science about it.
Thanks 😊
@@CanadianPermacultureLegacy please let me know how you go. There are plenty of others doing regenerative agriculture which includes MS cover cropping. I'd like to see another video about it when you get a handle on the science. The entire NPK system we currently use is so stupid. It's killing the earth and doesn't work on any level. Regenerative agriculture will probably go against everything you've ever learned. Welcome to the new old ways. 💖
@@CanadianPermacultureLegacy ua-cam.com/video/EX6eoxxoWKI/v-deo.html
This might help, good luck!
oh, check out my soil science video. I'm definitely many years into regenerative agriculture side of things. Thanks for watching 😀
@@CanadianPermacultureLegacy so you are many years into regenerative ag but still can't find science to back up multi species cover crops? Dr Christine Jones explained it pretty well I thought. You said you didn't understand how it works. Why not just ask her. Never mind. I apologise for wasting your time.
Happy to see this video because I've been confused about this topic. Logically I know that leaves and grass clippings start out as green, nitrogen rich sources - but as they dry they lean more toward the carbon end of the spectrum. I wondered why Comfrey seemed to be the exception to the rule. So maybe its not.. but I still want to grow it!
Yeah there is no exception to the rule. As green plants decompose, the nitrogen gets lost faster than the carbon, and they slowly get more brown.
Fantastic comments. Makes absolute sense. Thank you!
You and @GardeningInCanada would have SO much to talk about!
Very interesting way to look at permaculture - definitely worth using scientific knowledge to better understand "why"?
Thank you for your thoughts in your video, and thanks to all you people with your amazing good reactions!
As permaculture is only a few decades young, it still needs to grow more educated. My thoughts went to the native nations use of beans in the ‘three sisters’, especially when not planted together in a guild, but in a sequence. I was told (…) that in this case the beans were always grown in the year before the maize was grown on the same spot. This might hint on some advantage of the nitrogen fixer to later crops. Centuries of trial and error or, better, observation could bear some knowledge or practical science. As I work in gardens in Amsterdam, NL, it is hard for me to go and check this kind of knowledge, but you might.
and to be clear, I'm not saying nitrogen fixers don't work. There is a long history that they do work. Even if they can grow leaves and get their nitrogen from the air (leaving more soil based nitrogen for other plants), then they are a benefit.
The point of contention is that the nitrogen nodules themselves help other plants, and also that some people claim that the nitrogen fixers pump nitrogen to all the surrounding plants.
There's a section in Dave Jacke's 'Edible Forest Gardens' book that talks up the importance of nitrogen fixers for a while and then ends by saying something like "we're not sure how long it takes for nitrogen fixers to actually translate their nitrogen stores into benefits for surrounding plants, could be 10 years, maybe longer. Don't ditch the compost early on." When I read that I remember thinking 'huh, that's a disappointing ending to that nice sounding principle' Honestly though, it just makes the design easier - grow a diversity of plants, let them do their thing, it doesn't have to be complicated. Thanks for the video, good to question everything, especially the things that make us feel warm and fuzzy
Great conclusion 👌
I highly appreciate you sharing the information, experience and knowledge! Big thumb up to you for doing your own research and study then speaking out your mind frankly. As humanity stepping into the new Aquarius age, this is exactly the spirit that people need ～ collaborate and help each others, yet speak out your own idea/mind 👍👍👍🙏🙏🙏❤️🌹
Nitrogen fixers do work, but they of course don't shed their nodules... The benefit is that they can grow fast without outside input of fertilizers and they produce high protein biomass (for legumes at least), biomass rich in protein decomposes into nitrogen rich compounds (nitrates, nitrites, ammonia) which in turn benefits other plants around...
Fantastic video. So many good ones lately (and I always love the geek-out science moments!). My "nitrogen fixers", you are right, may work for different reasons. Shade is a big thing here in dry PNW summers and my main "nitrogen fixers", Comfrey, Goumi and Sea Buckthorn, all grow fast and provide good shade. The Sea Buckthorn and Goumis I would also grow just for the fruits. The Comfrey (yes I stupidly grew 'True Comfrey' from seed so yank off the flowers early and often) is so hearty via that taproot that I can constantly yank off those leaves to cover soil so have to water less in our dry summers. At least for the Comfrey, a big X factor for me is laziness. It's just so easy to drop those Comfrey leaves at the base of the plant and tree and not have to haul anything (I usually do it while watering). So, even if they don't "fix" nitrogen as I think you are probably right, they still tend to work for me. ...and totally agree that more plants of any kind help the soil. I have seen that working for sure!!! ....and also part of the lazy X-Factor....I always pee on plants in the yard rather than go to the house and waste water (in Spring and Summer anyway when the leafed out trees/shrubs keep the neighbors from getting an unwanted show.). Sometimes you have to be your own nitrogen fixer!😜🤷♂️
Yeah, and reading through all the comments (such as yours and many others) there are just SO SO Many reasons to do these things still, even if some aspects of them are in "myth" territory. Deep rooted plants provide low resistance water and air pathways down to the ground. SO they are still something we should include in guilds. Chopping and dropping things, even if it doesn't disassociate the root tissue, still shrinks them, doing the exact same thing, low resistance pathways get created. So many factors at play. The best thing we can do is just replicate nature as often and accurate as possible.
I pee on root zone of my plants as well.
I think you are correct on sacrificial plants. There is a lot of sound science with nitrogen fixing for cover crops (beans, peas, buckwheat, etc.) for fixing fields. Many of our farmers here in Kansas grow soy bean as a cover crop for this reason. The proof being in that the soils are not needing fertilizers in the coming years. Also, one big challenge commercial farms have currently is the lack of crop rotation and cover cropping. Where regenerative techniques are in place and planting multiple species they are increasing the interaction of nutrient exchange.
The key difference is there is a lot of good research on optimal time to till the beans/alfalfa under in order to maximize Nitrogen addition. Without the till, the beans are really just growing without taking N, which in itself is pretty good. Most of the N replenishment then comes from rains.
@@CanadianPermacultureLegacy In the regenerative fields they are not tilling the fields and increasing the yields without fertilizer. The fields they are tilling are having troubles. There are a lot of grant programs encouraging regenerative techniques and avoiding no till. I'll look for the studies and post.
In my experience, the benefits of comfrey are overstated. I'm glad I didn't plant more than I did. I'd rather give the space to a diversity of appropriately-sited native wildflowers/shrubs. In addition, the dictate to plant a nitrogen-fixer with every fruit tree seems tenuous at best, so I've generally ignored it (even on initially infertile soil). Observe, study, then ask yourself what would be growing on your site if humans had not altered it; plant your "useful" plants into a matrix of historically local plants (many of which are also actually "useful" to humans, and all of which are ecologically useful). It will thrive.
I've been planting rhubarb instead of comfrey because it's similar in function and... rhubarb pie tastes better.
@@OakSummitNursery Seriously, strawberry-rhubarb pie is the best pie ever, and I pride myself on baking a fine one! But how much rhubarb is enough in the landscape? A handful of vigorous plants provide more than we can possibly eat. After we eat/preserve our fill, I let them flower for the insects, but as is the case with comfrey, I won't be deliberately multiplying my rhubarb. Instead, I'm searching out and adding in a diversity of native plants for wildlife/insects, e.g. wild senna, NJ tea, dotted St. John's wort, shrubby St. John's wort, steeplebush, buttonbush, figworts, etc.
My bunnies eat comfrey and they leave great fertilizer for me so I value it.
Permaculture is a fairly new concept however the methodology has been around for centuries trying to ascribe a scientific backing is always going to be more complicated than necessary as we still don’t fully understand the human body let alone the extremely complex systems in place for growth of plants that said Mother Nature provides us with examples ie an unregulated and un manipulated forest the compact and diverse ecosystem with no waste that is self sufficient. Great video.
Centuries? I was thinking Mesolithic... It may pre-date the Invention of Agriculture as we know it.
@@jcrockett870 maybe I know it predates my grandad because everything he taught me about gardening is now the new thing. Lolz
@@ponypetedm Good for him.
We have alfalfa and weeds in our organic orchard. We let the plants grow as much as possible and then chop it up with a flail mower. There are drip lines that feed the trees and they are buried up to 10 cm of soil that has been created by this process. All of our peaches are softball size and sell every one. Over time the soil gets deeper and richer. When one walks on it, the orchard floor is very soft.
I love how you have a marker to measure the soil building (the previously installed drip hose). That lets you know it's working and you are on the right path for soil building. Love it.
Thanks for this. I think it's important to know what I'm talking about too.
Thank you so much for this video. I've wondered about the scientific nature of the memes around nitrogen fixers in the garden for a long time. I didn't track my source on this but I read once that you can tell if the plant is fixing nitrogen from the air if the roots have nodules. Last year I pulled up my pea plants and didn't see any nodules which, as I read, indicates that the symbiotic bacteria are not present in the soil. So, I bought an inoculant and will test for myself with pea seeds I have left over from last year's planting... I can't wait to see the outcome this year.
Thanks for stepping back and taking a critical look at some of the tenets of permaculture. They often sound good but that bioaccumulator label on comfrey always seemed suspicious to me. I’ve also never wanted to plant something that is so hard to eradicate that you may need chemicals to get rid of it.
To be clear though, the bioaccumulator label is actually likely true. See linked research in the video description. The contested point is "where" those minerals came from: the deep tap root (deep down), or the lateral roots (surface soil). There is no evidence that the minerals are mined from deep below.
However, there IS research showing just how many minerals it accumulates.
@@CanadianPermacultureLegacy good clarification, thanks
unrelated: the biggest advantage of annual seed saving is over your life and lifetime you are cultivating your own gene pool of stable superior crops. i suspect how most crops were domesticated was just that humans and other animals ate what tasted good and ignored what didnt, slowly domesticating them. If you collect data on each plant then in 50 generations of selective mass breeding you could COMPLETELY change the plant.
Nice a little section about media use knowledge.
I always wondered about the root shedding, why plants should do that.
Regrowing needs a lot of nutrients the plant probably has to get from the soil food web. So it converts the nitrogen into exudates, "feeds" it to mycelium and bacteria, which feeds higher soil food wen beings
I listen to what people have to say about their own experiences and, as you say, actual scientific evidence, but tend to be a little skeptical of anyone who seems to think they can significantly improve on nature. After all, nature has been doing this for, literally, millions/billions of years. In developing my front yard into garden space, my goal is to reach a point where most plants reseed and/or perennialize with little to no input from me.
It's honestly such an important way to think. As soon as we start radically departing from what nature has done for billions of years... and each organism has slowly evolved to excel at... and the orchestra of billions of them all working together in this intricate web... it really makes it questionable when we start doing things that doesn't COMPLETELY mimic what nature does. Amazing comment.
I have to say, the loud buzz and drone of leaf blowers every fall makes me despair at the ecological illiteracy of my neighbours. All those leaves are the food for the trees they love having in their yards.
Plant Nutrients in Municipal Leaves (1998). Joseph R. Heckman, Ph.D., Extension Specialist in Soil Fertility; Daniel Kluchinski, Mercer County Agricultural Agent; and Donn A. Derr, Ph.D.. Rutgers Cooperative Research and Extension. Fact Sheet FS824
I'd be such the annoying student in a PDC because I already know all the techniques, so I'd have my scientific skeptical brain going strong, not having to absorb the techniques. Never yet have I heard anyone explain the dynamic part of dynamic accumulators. Maybe you have? Elaine Ingham does tell a story of measuring the rate at which nutrients move from the roots to the tree tops, by having some researchers hike down into a cave and injecting into the tree roots, while other researchers stayed at the top looking for the markers to appear in the sap. I forget the tree and the timing, but it was extraordinarily fast.
I'd also point out that there is always leakage in nature. No nitrogen nodule is going to be able to contain 100% of the nitrogen it fixes. So some of it is clearly going to be found in surrounding soils and plant tissues. In a forest situation the roots of trees are all intermingled. I figure there's a lot of give and take happening. People have this mindset of tree root structures as this perfect dendritic sphere, but then when you look at the drawings that researchers have done of tree roots, they are much more irregular.
All great points. No barrier is 100%.
Also if we want deep roots, we can look no further than native prairie grasses!! They have some insane roots.
don't forget the mycelium networks!
@@ediblelandscaping1504 artificial fertilizers? But the statement "There is zero soil biome" is a bit strange. there is an aerobic environment from the water constantly being stirred. this facilitate microbes, so there should be something.
it's similar to how till agriculture fertilizer systems work, or pure chemical based hydroponics. It's all capillary action that drives the water and nutrients into the plant. This can happen with no microbiology, but chelation cannot happen, so the fertilizer must be chelated, ie. in a plant available form.
our hay meadows are primarily timothy clover. yields timothy predominance one year, then clover the next. the family has done this since (and probably before) 1800. one meadow, in particular, has been in production since 1980 with no addition of nutrients (including manure).
I’ve definitely heard the about shedding nitrogen from the roots, whether that’s beneficial who knows. There is the release of gibberellic acid when pruning which is said to help neighbouring trees grow. As for chop and drop depending on how fast the material decompose I’d assume that a lot of the nitrogen could just off-gas, the same way there’s a difference between nitrogen rich green grass and carbon rich dried grass.
What's cool to me is that we don't really know how or why it works and yet we can still help have a positive impact. I think that natural systems are so complex that we will probably never fully understand it all and they are so regenerative that as long as we aren't taking too much, nature is always working harder than we ever could to restore itself
A brilliant point.
Anything in this area needs to be approached this way. The natural world is so complex and we know so little about it, that the absence of proof isn't proof it itself.
So get out there and try it, see what works, and operate in the empirical space of trial and error. We may always know EXACTLY why something works, but we can control as many factors as possible and isolate good practices, and do those. And the best way to start is to look at nature and replicate what nature does.
I love your honesty and your desire to only promote concepts that have scientific backing. I do believe that Nitrogen can be transferred to other crops by stripping off leaves and twigs from Nitrogen Fixers and then INCORPORATING the leaves into the soil near the other crops. As these leaves rot down, the Nitrogen in the leaves should become available to the other soil. This seems to be working in alley cropping systems here in Zambia (see Gliricidia sepium a Wonder Tree for Small Scale Farmers, on You Tube). As far as recovery of nutrients from deeper down in the soil by deep rooted plants, I wonder if trees (as opposed to shrubs like Comfrey) might be more effective at recovering nutrients from deeper down? Under our conditions, I believe the trees (in an Alley Cropping system) are definitely providing photosynthetic energy year around, compared to the 100 days of a typical summer season maize (corn) crop. BTW I'm also an engineer (civils) and so am also very skeptical about the unsubstantiated claims made in many regenerative agricultural circles.
Yes this exactly. Even just the leaf fall and decomposition, that also. Most of the nitrogen came from the air, and is then put into the soil in the fall and winter.
@@CanadianPermacultureLegacy I'm looking for a different system, suitable for the Small Scale (almost subsistence only) Farmers of Africa. We have cheap labour, so stripping the leaves off new growth twigs and INCORPORATING them into the soil, is an option for us that you would not be able to afford. I believe that (a) leaves dropped in your Fall are probably much lower in nutrients (including Nitrogen) than mature leaves in their spring/summer peak condition (by Fall, I suspect that most trees will have tried to withdraw as many of the nutrients in each leaf (to be stored in their root reserves), prior to allowing them to drop) and (b) I believe that, left to decompose on the surface, most of the Nitrogen in any leaves (stripped or fall dropped) will return to the Atmosphere, rather than be absorbed into the soil. Horses for courses; we each have to find a system that is economically suitable for our conditions.
Watching this video, I realized that I have been parroting the nitrogen taking points. However, I do have some anecdotal evidence based upon my experience. I have a lot of Gliricidia sepium on my farm. Each year, I make some really great, fungal-dominated compost using it. I trim branches and then chop them in a woodchipper. I get a good-sized pile and allow it to compost, turning it regularly and adding moisture (if necessary). The wood chips from the branches provide the "browns" and the leaves the "greens". Once the material has passed through the composting cycle (~18 days), I lay it out in a bed about 4" thick, give it moisture, and cover it. After a week to ten days, it is loaded with lines of fungi. I have used this directly to grow healthy vegetables and fruits. You could say that this is a type of "delayed and processed" chop and drop. In my experience, I have found that chop and drop has value in adding organic matter, specifically carbon, to the soil. I have not found that chopping and dropping a nitrogen fixing plant is any better than chopping and dropping one that does not fix nitrogen. After all, there is nitrogen in the leaves of both types of plants.
100%
Just discovered the channel and love your vibe/mission, so thanks for all that you do! I think it's really admirable for you to admit we might be wrong about these common claims and to get the discussion going. I'm curious though, when you say that there isn't much (if any) scientific evidence to support these claims, is it that there aren't any studies that have been conducted to test these hypotheses? Or is it that studies have been conducted and seem to suggest that these claims are untrue?
Your point about the taproot vs feeding roots makes a lot of sense for why the nutrient accumulator claims could be false, since there doesn't seem to be a causal mechanism. But I'm wondering if there might be a mechanism by which the bacteria harnessing the atmospheric nitrogen for these plants could benefit other root systems inhabiting nearby soil, without the need for the host plant's rhizomes to die off. I'm 100% out of my depth on this topic lol, but just wondering if there is still something to the anecdotal evidence and we just lack the understanding to explain or identify the causal mechanism.
Just genuinely curious. Keep up the great work!
For the first thing, no I don't think there are studies to demonstrate it. But also I think there are some misunderstandings that are being repeated and parroted about 2 main things: that roots sever when a plant dies back (they don't, they mostly stay intact and just shrink) and second, that the nitrogen nodules are nitrogen fertilizer pellets. They arent, they are just homes for the root bacteria.
Infact, the nitrogen nodules themselves are more akin to a factory, than a warehouse, if that helps explain it a bit.
The main benefit of a nitrogen fixer is that it is self sufficient, and grows organic material without drawing down soil nitrogen reserves. It then makes plant matter (stems, branches, and especially leaves), and in the fall the leaves fall. A lot of this nitrogen was taken from the air, and is therefore a soil input.
Then when the plant completely dies, the entire plant mass (above ground and also the root mass) will be consumed by soil life and turned into soil, and a lot of THAT nitrogen was also "free input".
So overall, the process is much slower than permaculture books may have you believe. It's still a valuable member of a guild, it's just not this immediate fertility battery that it is sometimes sold as. It is a long term fertility play.
@@CanadianPermacultureLegacy Wow, thank you so much for taking the time to write out that amazingly thoughtful response! I really appreciate it and that makes a lot of sense. Stay awesome my friend!
Suzanne Simard has shown that the transfer of carbon between trees is mediated via the mycorrhizal systems. She shows intimate communication between plants via this same system. Likewise, we know that the breakdown of organic material in the soil occurs as the result of soil bacteria and fungi and that these nutrients are passed along to plants. Although we may not know exactly how nitrogen, carbon and other nutrients are passed between plants in a guild, we can only establish the optimal balance of plants in guild. Once it can be clearly established that certain plant combinations are beneficial, the next phase would then be to determine why and then to determine the how. The myths are in the how say a nitrogen fixer is beneficial to a guild. However, the scientific role of the horticulturist is to clearly show that a nitrogen fixer is beneficial or not.
It's always good to have that big picture in mind for sure. I always want to know "why" but sometimes we're decades or centuries from being able to figure out the answer. Sometimes we may not even be capable of understanding something as different to us as plants. I talk about this a lot in my "plant intelligence" video. We know just so little about plants.
So often the best we can do is an empirical approach. Try something, see how it works. Try to control all the variables and only change 1, then see how that works. Rince and repeat for the million or so variables and see if we can learn anything at all. But when it comes down to it, we just do our best and try to mimic nature as closely as possible. That's the way to get as close to the mark as we can.
Interesting to hear your thoughts on this, it is a very important topic. I find it almost impossible to whether most garden advice is based on actual facts/research or merely hearsay, especially as a lot of advice is conflicting regarding planting times, pruning, pollination etc.
I am so glad you addressed this and shed some light coming from a scientific perspective. Thank you! Since you mentioned a total sacrifice of nitrogen fixing plants would be most beneficial, I'm wondering if annual native nitrogen fixers are perfect for this job. For example, partridge pea is a nitrogen fixer that's an annual and grows from seed again each year. It also self sows very easily so should be pretty hands off. Bonus that it's native, at least in my area. Keith, I'm curious to hear your opinion about whether this would work as a yearly auto-sacrificial nitrogen-fixing plant. One thing I'm wondering is if it's not ideal for fruit trees to get the flush of nitrogen at the end of the season when the partridge pea would die off since the trees are about to go dormant...
I think its very possible. The only thing that may need to be answered first, is WHEN do the nitrogen nodules swell.
If they swell in anticipation of flowering and fruiting, and the plant then uses that nitrogen to grow fruit (most N is used for leaves though), or if the plant uses that N towards its end of life, to ensure fertility for the seeds it drops, then it may change things.
In short, I don't know, and there is no evidence that supports it scientifically. However, that also doesn't mean it's not potentially true, because if there is no money in the science, then it won't be done. But that doesn't mean it may not be factual.
Long answer for.... I don't know. But it sounds feasible and makes logical sense.
I've this bad habit of questioning everything, regardless of source :) resulting in a constant string of experiments, most of which seeming to confirm the "known facts" - and every once in a while I stumble across a new nuance, which I'm not in a hurry to explain, but rather catalogue under "yet unexplained facts" .
Take sunchokes, for example. I cultivate in 2 shadow locations and 1 sunny locations. One shadow location does much better than the other shadow location. The sunny location has mixed results, as well. Next to a great, vibrant plant, I have this stunted, struggling one.
Daylilies. After 13 years of neglect, (and thriving), one of the patches shows signs of "rust"..
Anyway, my nitrogen fixers of choice are legumes. Yearly and edible, what's not to like? And garlic and chives are my pest control :) Currently working on establishing garlic chives - why is it so difficult?
Sea buckthorn - it is the height of the summer - gazpacho should be on the weekly menu - especially if the cucumbers are starting to produce like crazy - a handful of berries will bring it to the next level!!! Savory smoothie, is it not?
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Looking at the city with fresh eyes, I can see a lot of trees with sea buckthorn-like foliage, but too tall and rather trees than shrubs - any idea what can they be?
russian olive?
great comment as always, and a great attitude to have in my opinion.
For the shrub, I agree it's highly likely either Russian Olive or Autumn Olive, but without a picture it's hard to know.
Autumn olive, I did a video on them, so you could find that and compare. Russian Olive is very similar but has beige dusty berries and more of a beige color leaf.
My own thoughts are in a similar space to yours. But I have been interested to read some more recent science on nitrogen fixing bacteria residing in non-photosynthising cells in leaves and stems of plants. Basically the group of "nitrogen fixing" plants may be far broader than traditional permaculture currently realises and explains why some crops outside of those traditionally considered nitrogen fixing (the study looks at hemp) do well in poor soil. Look at a recent study at Rutgers University, "Historical Evidence for Nitrogen- Transfer Endosymbiosis in Non-Photosynthetic Cells of Leaves and Inflorescence Bracts of Angiosperms". Catchy Title. I think the implications may really question a lot of what we have considered the basics of guilds. Although bio-accumulation of matter on the surface of soils is great for so many other reasons that maybe it doesnt matter.
ooooh this was extremely interesting, thanks fot posting it. I'm going to have to reread that tomorrow to make sure I understood it properly.
I love your videos, and so appreciate your honesty, and willingness to rethink your plan as you research & find new information (or not)!
What do the pups think about the chickens?
They are all nuts around them. Lucy is the best, she sits and watches them kindly. If they freak out and flutter about, she will get excited, but if they don't run and if they stay calm she does too.
Harry and Ginny are nutso maniacs. They bark and circle and scratch the cage. They get the chickens all riled up and stressed out. So we are trying to work with them one on one. Sit them out there, hold them and pet them and force them to just watch them next to us, without freaking out. It's going to take some time for sure.
With respect to tap roots, I remember a geology prof explaining the fluctuations of calcium in the soil with the variations in the local water table. Tap roots plants like dandelions compared to grass with a fibrous root system would be at an advantage in times of drought for the collection of such an ion (amongst others). Anecdotal observation of my lawn mower clippings with dandelions amongst them suggest plants whom get this mulch look happier.
Thanks! Love this info. I have cowpeas planted all around my baby fruit trees. I guess that will be the sacrificial method
Isn't the taproot also a great fallback in a drought? I don't think a comfrey plant, no matter if it's 3-5 feet tall, needs a 50-foot taproot for stability! I expect that its longevity may be assured by access to water deep in the ground.
I am of the same mindset---let me see some data! While not necessarily addressing "tree to tree" nitrogen transfer, this article appears to have studied nitrogen transfer from tree to cereal crop interplantings, using N isotope markers. I've only read the abstract, but what I gather from the study is that "it depends". Its not a single variable that can be controlled. The study suggests that under the right conditions, yes it does occur. I'm still digging for more studies.
I understand it a little differently. N-fixer as example: you chop off thin branches full of leaves (high N material) and mulch a different plant with it, then the nodules in the root zone give a sort of 'food storage/grow juice' bump to the coppiced N-fixer, compensating it back to balance and re-accumulating N for itself for next time. Also the mulching inherently just adds organic matter to support microbial life which is doing a lot of things to make N and other stuff more readily available and with higher storage capacity for excesses from things like animal pee for example.
This is the real and best way to think about it.
My key principle is to observe what is functioning in the native ecosystem and enhancing and expanding that. The best think I’ve done for my soil is to buryi the wood, leave the leaves and direct the water.
This is the way
Confused! I have gardened very successfully for over 40 years and I listened to this and think what hell? Good on u and anyone else who gets this, I don't, I will just grow my food and apparently Mother Nature just takes care of me. 😏
Autumn olive is a nitrogen fixer. The USDA found "Analyses of black walnut tree diameters 13 years after planting showed that interplanting autumn-olive, black locust, and European alder increased walnut tree growtb, but only at certain locations. Interplanting autumn-olive resulted in increases of 56 to 351% at four of five locations and all species resulted in doubled walnut growth on an upland site. The interaction between treatment and location indicates that a fuller understanding of site and nurse species characteristics is needed to obtain the potential benefits of mixed plantings."
I think it‘s great that you look for scientific backing of the things you spread and in doing so encourage us to do the same. Based on my research, I do think that tap roots on certain plants make nutrients available to other plants that plants near the surface might not access. Mineral ions like calcium are dissolved in the water that plants take up over their roots. Calcium has been shown to pass through root tips, including tap roots. Although there are more nutrients in the top soil than in lower layers, if the water flowing in the lower layers manage to dissolve mineral nutrients from rocks they pass over, then these nutrients can be picked up by a tap root as it takes in water. These nutrients are then stored in the root until the plant needs them. The nutrients are not available to other plants until the plant with the tap root dies and the nutrients are made available to the microbiology in the soil at the surface (provided the nutrients have been used to build plant matter above or near the surface. Nutrients that are available in this way need to be ones that can actually be found in the lower layers, like calcium ions.
dandelions are a great case study for this exact phenomenon. I wish more research was done on them and their ability to capture calcium and return it, and exactly how deep they do this from.
Thanks much for the video! Neat comments to read too.
Chop and drop is a lot more about feeding the overall soil food web. Obviously compost, especially vermicompost is proven powerful stuff. It’s the byproduct of all the organisms in your food web that you’re feeding and sheltering with chop and drop
There's a few things I would like to clarify:
- The benefit of the nitrogen fixers could also be this giant pump of carbohydrates into the soil food web. If the fungal network is supported by these fast carbon pathways, there is more capacity to in turn support the productive species.
- There might not be much evidence for where the nutrients are coming from in comfrey and I agree it might just be the feeder roots. But I have certainly seen scientific evidence for the soil around comfrey plants to be higher in plant available nutrients than surrounding areas without comfrey.
100%. This video isn't to debunk nitrogen fixers in general. They still produce root exudates and leaves which drop, both of which taking the nitrogen they use from the air. They absolutely take that nitrogen and put it into the soil. The mechanism for it however is what I take contention with. There is very little to no evidence that chopping them causes dislocation of root nodules, despite many many people claiming that's what happens.
@@CanadianPermacultureLegacy And yet Geoff Lawton has said it in the past and as far as I know, never retracted it. Though he doesn't seem to say that it any more.
Love your videos, especially because of your scientific analysis of everything, i’m the same way. That’s the only way we make progress, as older theories are disapproved or improved. I’ve wondered the same thing about tap rooted plants extracting large amounts of nutrients from what is often poorer quality deeper layers of subsoil, but I also wonder if deep taproot serve another purpose, other than the obvious one of added stability. Wouldn’t deep taproots also allows those plants to access water at much deeper levels and outcompete less blessed plants during times when moisture becomes scarce. What are your thoughts on this?
Yes, and more specifically they provide the pathway itself for water to reach deeper into soils, which then allows life deeper into soils. And when the plant dies (deep taprooted annuals), there is now also organic material deeper in the soils. Very important plants!
Exactly, they break new ground into compacted subsoils to the benefit of all forms of life
The idea that plants share nutrients has been varified scientifically. You can look up the work of Susan Simard on youtube and elsewhere for that. I do very much agree with the gist of what you are saying, and there is always a good reason to be careful with what we say or write as it may be passed down information that has not been varified scientifically. The part about the tap root not being a feeding root is possible but also not varified from my understanding, but your statement that it is all about stability might also not be accurate. Many plants with a deep taproot are doing so because they search for water at greater depths, like many desert trees. It would be interesting to know under what circumstances someone was able to find a comfrey root at 100 foot depth, and what was happening in that area in terms of water issues. I don't write this to naysay what you were on about in this video, because your way of reasoning is very valid and well thought out. Great content as always.
Great video, Thanks.