there’s a commonly held belief, ie @a_Vivaldi, that nitrogen fixers only provide N to their neighbors via leaf drop, chop and drop and so on. but there’s plenty of science documenting that plants trade their resources with each other via fungi…
goumi is good at producing N, while its neighbor rotheca myricoides is good at storing water. so they trade N for water. they benefit from each other’s differences. obviously this applies to markets in general. we all have different skills and information.
The paper here didn’t measure N, just phosphorus and carbohydrates. I don’t doubt that plants might also pass some form of N to fungi, or the other way around (probably more likely, plants usually are providing carbohydrates as they can produce it easily).
I’m not sure a market is necessarily the best analogy. The measurements they got could just as aptly be described as “healthier plant and fungal symbiosis was characterized by higher amounts of nutrient exchange, whereas low functioning symbiotic relationships were generally abandoned quickly and saw less nutrient exchange.” It’s always a bit messy to anthropomorphize nonsentient behavior, describing it as a market makes it sound like conscious choices are being made, when really it’s no more conscious a choice than the tips of branches “deciding” to reduce their water demands by dying during a drought so that the main stem can survive. It’s a “purposeful” activity, insofar as there’s a real reason why the branches die first, but it’s entirely mechanical, not intentional behavior.
Plant to plant or plant to soil to plant or plant to fungi to plant nutrient transfer surely happens to some extent or other. I don’t deny that. It’s just not something I’d count on as an effective and reliable method of fertilization.
I have degrees in science, and I have a diploma of permaculture, and can say that permaculture is not all science. I wish that it was, and I paid to study it in the hopes that it would be largely science driven, but by in large it isn’t.
I am not saying this to dismiss permaculture out of hand. There are certain concepts that work well in certain situations. The way I grow things organically using IPM and integrate animals into the system would probably be considered ‘permaculture’. I am saying that you need to be careful with anything claiming to be permaculture and to research any claims.
Science and research through the pressure of ideology can get warped. Permaculture undoubtedly has many different schools of thought within its roster of adherents. The idea of using N. fixers is emotionally appealing, especially when we imagine cooperation between plants almost like a loving alliance. Vivaldi may be right that it is risky to anthropomorphize plants but often that is exactly what the most inspired gardeners do- not so helpful when discussing the science, though.
I used to think of gardening in general and orchard keeping in particular as best done in harmony with nature, but nature taught me that it really doesn’t care if I harvest ripe fruit or not and certainly isn’t interested in providing me with the very best tasting fruit that stores well.
I get that by conning and manipulating nature and mostly outright fighting it. Love and respect your enemies when you are trying to grow fruit- at least here in the challenging humid region. Nitrogen is the least of my worries
However, if anyone has anecdotal or scientific evidence that companion planting helps to either establish or maintain fruit trees, I’d love to read about it. My experience has been more along the lines of allelopathy, where herbaceous perennials stunt fruit tree growth with chemical warfare- it must be fear of being shaded out by an establishing tree- I can smell the adrenaline . At any rate, meadow species probably don’t tend to ally with forest dwellers.
In one of my viticulture courses in grad school, we tried to calculate if a vineyard’s nitrogen needs could be obtained solely through cover crops. Juice nitrogen content is a parameter that is routinely measured in wine grapes as yeast needs a certain amount for fermentation, so it’s easy to estimate how much nitrogen is removed during harvest each year. Using average nitrogen yields and release rates for common cover crop species, you can get kinda close, but it’s not possible to completely replace what is lost annually. I don’t think we even factored in nitrogen loss through leaching.
For me as a fairly small-scale grape grower, my experience has been mostly negative as well. And some of the benefits are impractical on a commercial scale. We have a lot of mustard that comes up spontaneously in the vineyard, and while it’s great for reducing nematode populations, for maximum benefit it has to be tilled into the soil in late winter before it flowers. Our soils are far too wet at this time of year to even think about getting a tractor out. Mustard also hosts false chinch bugs, which, as the mustard starts to die back in late spring, move en masse to grapevines, stunting or killing newly planted vines.
Leguminaceous cover crops host the three-cornered alfalfa hopper which vectors grapevine red blotch virus. Because of this virus, we have had to remove nearly 25% of our acreage over the last decade. Research is still going on to determine whether having more legumes will increase alfalfa hopper populations in vineyards or encourage them to stay away from grapes.
I don’t doubt that there are enormous benefits to planting cover crops, but the benefits need to be weighed against the negatives, and especially in the wine industry, people can be blinded by ideology and pictures of pretty vineyards.
Biodynamic agriculture … is like magic, with no scientific basis.
A few permaculture pseudoscience…
You have to make mounds of Hügelkultur and you plant tree on top. I’ve so often seen people find themselves with trees that grow lean after a few years because the mound has been washed away by water or the dead wood has decomposed, or trees that seem to sink into the ground. I know that Hügelkultur mounds have nothing to do with permaculture, but it’s like a fashion to add all kinds of things to permaculture.
Use invasive plants, it’s ok… It’s not a good idea to plant comfrey in a small garden and have it grow everywhere. Saying comfrey is a bio-accumulator, but all plants are bio-accumulators, and if you compare grass with comfrey, you’ll get a similar NPK and trace of minerals.
I have nothing against the philosophical side of permaculture, maybe just the section that says to share with nature, no it’s not sharing when in winter, a few rabbits eats the bark of all your fruit trees. No, it’s not sharing when 5 or 6 raccoons come to eat all your grapes in 2 or 3 nights. Or the birds that come and take a bite out of each of your apples. Animals are sometimes really hungry and don’t care about sharing.
Having plants scattered all over the place increases harvesting time, cost more than conventional. Saying that a permaculture farm generates more money than convetional farming. But when you ask them to see the book, you dig a little, and you see that they hire woofer (work for free) or that training takes up a large part of their income.
I don’t see conventional agriculture is better, i just say, permaculture is not the magical solution.
OP, you can probably grow crimson clover in your area. It is very good for producing nitrogen. But it needs to be planted in late fall. It reseeds itself.
Do you plan to have any animals like chickens, duck in your food forest? Comfrey has very deep roots and they do bring up lots of nutrients.
However, chickens will totally decimate them in a matter of minutes [they are VERY fond of comfrey.]
As you grow other things near your trees, you may want to be mindful that they must be good companion and not have requirements that put them at odd, like growing too big under your tree and getting in the way of harvest, or have thorns, like some gooseberries.
As a Permie myself, I’d want to have 2 crops otr more in the orchard. Let’s say you would want those gooseberries, it is ok to plant them nearby but probably not right next to a tree.
Into the nitty gritty of science, ‘theory’ is hypothesis tested many times and found to be ‘true’. In a non-science discussion the word obviously means something different to most people, but I just wanted to clarify/qualify your intended statement. I think I understand what you were going for. Math is based on mathematical theories, after all
I would say the closest comparable scientific areas of expertise which should be studied alongside permaculture are soil science, hydrogeology, and botany. Covering those things one would understand how soil works, how water interacts with soil, and how plants grow. Astronomy isn’t going to help with using the sun any better, but understanding the photosynthesis part does.
Where permaculture appears to intersect is vaguely acknowledging the hard science with incorporating slope, water retention, soil building, and guild fabrication. Everything I’ve read related to those topics so far seem to get it ‘close enough’ to remain valid and in line with hard science.
Many people who put down permaculture and biodynamics insist that they aren’t science. Almost always, when I hear people saying this, they are really describing outdated Newtonian science. This is as if the 20th and 21st centuries never occurred. Come on people! Niels Bohr. The Heisenberg uncertainty principle! Albert Einstein!
Permaculture and biodynamics are exploring the effects that happen when you consider that your observation of the experiment actually affects the experiment. Many of the practices have too many variables to really completely measure on a minute basis. I mostly do permaculture and I use some biodynamics practices. I acknowledge that the biodynamics practices are really quite bizarre sounding. I think that permaculture and biodynamics open us up to see things in a different way. Maybe don’t spend all day killing those weeds. Did you know that everything that you killed was edible or medicinal? I find that combining many of the practices makes it really hard to measure precisely in a Newtonian physics way, but they all work together. I can’t really tell what is from compost tea, biochar, deep mulching, biodiversity, nutrient accumulators, nitrogen fixers, underground mycelium, tree exudates creating a soil food web under the tree, or attracting beneficial insects, but they all work really well together.
My chickens steer clear of it when free ranging. They nibbled it a few times when I first started growing it, but they were not impressed. This is Bocking 4 though…maybe 14 would be different.
its controversial if this is truly beneficial but its is still beneficial to have another different species growing near it as it helps spread out the pest/ disease load. ive never read anything that completely debunked the benefits of companion planting N fixers with other trees. there are many that do and swear it works and show the results as proof.
All the Agricultural scientists around here encourage growing clover in pecan orchards. They claim up to 100# per acre you save or add to your nitrogen up load. It has been well documented in numerous articles and studies.
I do have Bocking 4 also so I’m not sure why there is a difference between your chickens and my chickens in this respect. Mine are Sapphire blue chickens and they have a reputation for being excellent foragers. Maybe they will go for my comfrey just because they are really good foragers?
Perhaps it is like deer who won’t come close to eat my hostas as long as there is plenty of food they can get to in the forest without risking getting shot at?
That’s a bit of a leap to suggest my girls aren’t good foragers. I consider them very good. They’d just rather eat the grass, clover, plantain, and other “weeds” growing in the yard or overgrown areas. I think the somewhat fuzzy leaves are a turn off for them. The deer will eat it though.
ive had the same experience. they will eat it only if there’s nothing else. makes a great tea to help plants get established or 1 that is struggling. i also grow rhubarb that i can eat and use the big leaves similarly so i prefer them over comfrey.
. At any rate, meadow species probably don’t tend to ally with forest dwellers.