Nitrogen fixers and nutrient accumulators for fruit trees?

from reading a few permaculture books it seems that planting nitrogen fixers and nutrient accumulators under fruit trees would be beneficial. i was wondering if these specific nitrogen fixers (strawberry clover, lupines, blue false indigo) and nutrient accumulators (parsley, dandelion, yarrow, comfrey) would be good to plant around the base of fruit trees or would they cause competition? does anyone have experience planting these with their fruit trees? thanks!

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I have 3 apple trees planted in a food forest bed… with goumi bushes planted between them.

Apple-goumi-Apple-goumi-Apple.

I keep the goumi bushes pruned for height at 6 ft tall… they are all getting along just fine.

In some locations (hot, sunny) many fruit trees need protection from the hot evening sun on the trunk area… a goumi would work well for that… if planted on the south/west side.

Goumi produce good early fruit and are nitrogen fixers.

I have not tried any of those that you mentioned.

Good Luck.

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Im happy with white clover…its a nitrogen fixer and brings the bees to the show. Keeps weeds at bay and is just a good overall thing to have in an orchard.

If you have sandy poor soil like stephan sobkowiak and his permaculture orchard he has some great videos on nitrogen fixers…

My soil is fine so i dont need them…plus i dont want big trees… or alot of growth to prune… so im not wanting excess nitrogen for trees myself…YMMV.

Some folks use hay or mow onto their trees for nitrogen boosts i think.

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i planted several goumi bushes a few weeks ago in between my fruit trees

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i followed Stephans lead, planting autumn olive, goumi, pea shrub, sweet fern, clover and false indigo near but not under my fruit trees. i also under plant with bush fruit and fruiting groundcover. comfrey is nice for chop and drop but rhubarb is just as good and gives you something to eat and the leaves are huge and can smother a 30in area of weeds with 1 leaf. like comfrey, they need 0 care. i also plant stuff like walking onion, chives, marigolds and herbs that deter pests around the trees. buffalo berry is another one i want to get.

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Hi Jamie

You are in the Florida panhandle, correct? If so, that’ll have a fair bit of bearing on the extent to which those principles will be applicable to you.

Permaculture design carries with it certain assumptions about nutrient cycles and soil building that may or may not be true in high-rainfall, high-humidity wet subtropical climates. Organic matter, for example, is an excellent soil builder in temperate climates and in some Mediterranean climates. In the Florida panhandle, organic matter is likely to break down fast enough to have a very noticeable N-binding effect, and it tends as well to not be especially persistent in the soil, lessoning its soil building properties.

Beyond that, it’s useful to also keep in mind the benefits, and limitations, of these systems. So for example goumi is a nitrogen-fixing plant, one of the non-legume ones. However, as a perennial shrub, it’s going to be contributing very little N to your soil, especially initially. Leaflitter, and a marginal amount of root growth/dieback cycling, is going to be the pathway from N and other nutrients back into the soil. Which, if you consider how much leaf litter it takes to make a cubic yard of compost, and then consider that an entire cubic yard of compost (a pick-up tuck load) will have about 8 lb. of N total, it begins to be pretty clear that it’s going to be years and years of leaf litter before you see much of a fertilization effect, especially since not all of the nutrients in the leaf litter are going to be recycled. A lot of the N will boil off into the air, and given your climate a non-zero amount of the free P will leach away into the nearest creek.

Now, that’s not at all to say this stuff is useless. It’s not. But arguably, the ground cover and leaf litter stimulating microbial activity are the primary benefits, not the nutrient fixation and mining.

All that being said, if white clover will persist in your microclimate (in the South it likes part shade and consistent summer moisture), then that’ll be nice. The various annual clovers like alike and persian could be doable during the winter, but you’d have to cultivate the ground each fall to plant them, which might injure your trees, and the sudden addition of dead plant matter in late spring would have to be carefully managed. With the others, I’d consider whether or not they will cause logistical issues (8 ft tall sun hemp is great for building soil and smothering weeds, but it’s also 8 ft tall.).

As for competition, it really depends. Stone fruits are often best when a little bit constrained, especially late season. Citrus on the other hand, while it appreciates very-light shade once you start getting as far south has Florida, probably doesn’t benefit from root competition seeing as when it ripens. Subtropicals and true tropicals are beyond my limited knowledge, so probably a mixed bag. Overall some degree of living ground cover is almost certainly a good thing, just as a degree of soil building, and a degree of chemical fertilization, all have their proper place.

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my clay-based soil also holds in nutrients like water, so very little leaks out. why i need so little imputs in my food forest. i also have been mulching in between my bushes and trees with woodchips annually until i fill in all the spaces. then ill stop putting it as everything is doing its thing, keeping the weeds to a minimum.

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Oh I wanted to add: building the soil and improving it’s structure is good, but can only be done up to a point.

The total organic matter in your soil is going to depend on how much you’re adding, of course, but it will be at some equilibrium point between addition and decomposition determined by your soil temperature, moisture, texture, and a few other things. As mentioned before, you’d probably not be advised to shoot for an especially high equilibrium point given your climate. A few % organic matter is perfectly reasonable, especially from growing fruit rather than vegetables.

But in addition to that, the actual aeration, chemical activity, and moisture retention of your soil, the fluffiness and carrying capacity of it, can be improved with things like organic matter, deep rooted plants, etc. But only to a point. After all, it’s ultimately the physical properties of the mineral content of your soil that are going to decide things in the end. Fluff it all you want, sand will collapse back on itself in short order, for example. So while you do want to try to improve things, just keep in mind that once you’ve eased any serious compaction, and perhaps drained away an excessively high water table, there’s only so much your can do that will actually have any major effect.

Which is why it’s a lot easier to do the soil building and conditioning beforehand. The ideal depends on your situation and growing needs, but generally in our region doing some deep aeration and incorporating a large quantity of expanded slate in heavy soils, and/or a large quantity of fine material with a high CEC in light soils, is one of the few things you can do to permanently improve the chemical, hydraulic, and mechanical properties of your soil.

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I have hairy vetch and white/red clover growing all around my trees and fields. I know Dale Hendricks grows hog peanut around his pawpaws for the nitrogen fixing and the extra cushion it provides to ripe, falling fruit.

Someone mentioned comfrey…I grow bocking 4, but not around the trees because of how deeply it roots. I just chop it, shred it, and drop it.

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@jamie

This may be good for your area.
I saw the test plots at the University of Georgia in Tifton. They look great.
.

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perennial peanut popped up in my lawn out of nowhere last year

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i feel like i have to constantly add amendments because i have sand for soil

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i was also thinking about planting moringa in between trees? i have seedlings that i want to put in the ground come spring. of course it would die back in the winter but would be good for chop & drop during the warmer months.

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check out permaculture pasture farm on you tube. i believe Billy uses moringa as well as others. his channels a great resource. you have the exact opposite soil that i have. i wish i had a couple dump truck loads of sand to add to mine. instead, i use fine river gravel to help with my drainage.

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Nitrogen-fixing plants use the nitrogen they produce for themselves, but when a piece of root or a dead branch decomposes, that’s when other plants can take advantage of it. I don’t like the pseudo-science shared by permaculture. Fruits tree need very little nitrogen, too much and no flower. Best things for your fruit tree is ramial wood chips.

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i agree. there’s a lot of good info. with some hopeful unrealistic expectations thrown in. diversity and companion planting has its merits but it will never be as productive as a orchard will be. i like it because i dont need to do much once its matured. i have so many fruit trees and bushes, even if they dont put out huge harvests i still get plenty. I’m a big proponent of woodchips esp. arborist chips.

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Yeah I don’t really try to nitrogen fix. I just let the clover and vetch do their own thing. I’ve thrown a little extra clover seed in the pawpaw grove, but those are nitrogen hungry anyway. Everything else just gets a little compost and mulch and I try not to fuss too much with them.

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Can anyone recommend a source of plants for this peanut as I’d like to give them a try?

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Broad leaf N. fixers tend to attract fruit attacking plant bugs in my region, especially towards peaches and pears- and especially white clover. When you are mowing, the bugs tend to jump on the trees, which makes it worse. I would love to see research showing they can be beneficial to established fruit trees. They also tend to suck a lot of water and may not compete for N with fruit trees but probably for other nutrients.

Once fruit trees begin to bear adequately, summer N. may do more harm than good by inspiring excessive vegetative growth, although I haven’t any reason to believe this can become a problem with N. fixing plants but I’m pretty sure it can be with too much organic matter in the soil from year after year of mulching. Of course, this also causes the release of a lot of N at the wrong time for fruit and provides more available water, which can be beneficial or harmful depending on how much rain you are getting on any given season. .

N “feeds” the fruit in spring and vegetative growth in summer- I bet N-fixing bacteria is most active in summer and not spring. .

Ideas need to be evaluated with real-world comparisons.

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Biodynamics is pseudoscience. I was under the impression that Permaculture was all science. Granted, there’s an overabundance and over-reliance on theory with comparatively little math to serve as proof-of-concept. But outside the biodynamic sphere, I haven’t seen any whacky stuff that would suggest permaculture to be a pseudoscience.

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