Ground covers, green mulch, green manure

Document your results with different mulches, seeds, mutations, TC or other experiments.

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movenosound
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Ground covers, green mulch, green manure

Post by movenosound »

I've brought this up in posts before, without much response. This forum seems like the proper place to bring it up again. Since the addition of nitrogen to bamboo is so important, it seems natural to investigate the addition of nitrogen-fixing plants to a grove to add nitrogen to the soil. So far I have focused on clover, as it seems most likely to be manageable as a short, ground-cover, that will provide the added nitrogen, while still looking good. That is, clover will still look good if it is kept cut low, otherwise it will get tall, and look like a big weed. There is a huge amount of information available about legumes as cover crops, and much more information on the whole rhizobia species of bacteria that are responsible for the fixing of nitrogen, than information on the mycorrhiza symbioses. While mycorrhiza is still a subject that I am going to investigate, the addition of a cover-crop is much more practical and just more simple. I can pull up a clover plant with roots attached and see that a rhizobia is present and hard at work fixing nitrogen, because the nodules present on the roots are easy to see. Mycorrhiza, on the other hand, are not easy to see with the naked eye, so they require some microscope work, and there is simply much more intense investigation that is needed.

A good page to start learning is here: http://www.attra.org/attra-pub/covercrop.html
On that page you can find some things that will get most people thinking about the potential that using legumes in their gardens can provide. Such as:

"The contribution of organic matter to the soil from a green manure crop is comparable to the addition of 9 to 13 tons per acre of farmyard manure or 1.8 to 2.2 tons dry matter per acre."

Or that the use of leguminous cover crops can provide 40 to 200 pounds per acre. In the instance of crimson clover, an average of 100 pounds of nitrogen per acre has been observed. I know that most of us here are not growing on acres, and that this data represents a farmer cultivating these legumes in a agricultural environment, but that doesn't change the fact that incorporating legumes in your garden can help add nitrogen to your soil, and perhaps even add a significant amount, and perhaps save you a significant amount of money!

I would like to ask anyone interested in this subject to suggest experiments, ask questions, or flat out tell me I'm wrong, but I don't see any dialogue on this topic being a negative to the subject on growing bamboo.
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Re: Ground covers, green mulch, green manure

Post by needmore »

I've experimented with clover and buckwheat but to my eye they just made the areas look too messy. I did not want to till into areas with rhizomes so I ended up pulling them all back out by hand. I believe in the science but want a cleaner look personally.

BTW - I was waiting on friends in a restaurant that has books to read at the tables - I picked up one on Chinese herbal medicines and saw a reference to a medicinal fungus that grows on bamboo roots.
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Re: Ground covers, green mulch, green manure

Post by Alan_L »

I think for larger groves the shade would be an issue for the clover or other legumes, wouldn't it?
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Re: Ground covers, green mulch, green manure

Post by Mackel in DFW »

Green manures open up compacted dirt with deep root systems and supply organic material to the soil. So the big story is not necessarily nitrogen per se but rather, carbon, imo.. Legumes supply carbon without removing nitrogen, perhaps that is the key to their beneficience.

But the effectivenes of green manures over actual manure on a small scale is at least questionable. There is a rich microbial miliu in manure, while with legumes we are essentially increasing the presence of a fungus within the soil that is not symbiotic as far as I know with bamboo roots.

But, nevertheless, bamboo doesnt grow in a vacuum in nature either, it grows in the vicinity of other root systems which may or may not be helpful to the bamboo.

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Mackel in DFW
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Re: Ground covers, green mulch, green manure

Post by ghmerrill »

One possibly could plant the clover, allow out to grow out well, then cover it with material like grass clippings or wood chips, which would smother it, allow it to rot and benefit the soil. You could do that every couple of years as a booster for the soil. That would solve the problem of the weedy look.
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Re: Ground covers, green mulch, green manure

Post by movenosound »

Gonna have to call you out on a point there, Mackel. Legumes do add nitrogen, and in pretty significant amounts, in the range of 10-300 pounds of nitrogen per acre when grown in an agricultural environment. The acting microbe is actually a bacteria in this particular process, a member of the Rhizobia genus of bacteria, and the specific species depends on the particular legume that is grown. If you decide to use these guys to add nitrogen to your soil, make sure that they are inoculated with the proper species. Some local ag supply places will carry legume seed that is pre-inoculated with the proper species of bacteria. To show what this looks like, I've loaded a picture of a legume with a nitrogen-nodule on it's roots to the website.
Image
Weird looking, eh? Usually they look more like fat pieces of coral. i have found good nodule formation on some of the clover and alfalfa that I have planted so far. I have read somewhere that if you cut open a nodule and you find a pink color, like above, then the fixing of nitrogen is proceeding along nicely. If the nodule is brown or black inside, then something is wrong. I need to re-verify that, so if anyone is interested I will try to go back and reference where I read that piece of info.

The green manures as a whole do add carbon, but basically in the form of organic material. Adding compost and wood chips and all that, also more organic matter. My concern, especially on the hillside where I am attempting to establish a grove, is that the material that I add may get blown or washed away. So the plan is to add soil and compost and manure and wood chips and then plant clover, alfalfa and other cover crops including grasses such as rye and let them spread their roots throughout the soil and cover the new material and get it held in place. Then, before the alfalfa and grasses can set seed, weed whack the heck out of em, and if they survive, hit them again, and maybe lay a layer of compost or wood chips. I'm not too worried about legumes spreading, and the grasses I plant will be annual warm temp and wont survive the winter here.

One of the most important things is to not let your soil be left with nothing growing on it. The mycorrhizal fungi, which might be what you are thinking of Mackel, does form a relationship with legumes and with bamboo and nearly 85% or more of the world's plants. These little guys do not form mushrooms, and they are really important. They are also present almost everywhere, though to varying degrees due to human interaction. Chemical fertilizers, especially those heavy in P, will diminish them, and so will tilling, growing non-mycorrhizal plants, such as mustard, broccoli, kale, and some others, and a few other things all diminish the amount and diversity of mycorrhizal fungi in a soil. Want to know just how important? Check these pages out:

http://www.rodaleinstitute.org/20090806/gw1

Back in 1996 Susan Wright, a USDA researcher, discovered Glomalin, a substance that Mycorrhiza leave in the soil, and it was soon found that this stuff is basically what is responsible for soil being 'GOOD' and soil lacking it being 'BAD'. And I mean literally. This is the stuff that causes soil to form aggregates, the little clumps, and to have 'tilth' a word that people from the Pacific Northwest cant seem to use enough but which I find somewhat ambiguous, and allows water to be held along with air in a ratio that is beneficial to plants, and is in itself a huge source of carbon. In fact, glomalin is now understood to make up around a third of all carbon found in soil. That is a pretty significant fact, in my opinion, though I am pretty interested in this subject.The following website tells all about it:

http://www.ars.usda.gov/is/AR/archive/s ... il0902.htm

And if you want to learn how to produce your own mycorrhiza inoculant, this website shows a great means of creating a soil that has a very high number of propagules per square centimeter.

http://www.extension.org/article/18627

I am thinking of making a trip down to the Bamboo Garden Nursery outside of Portland to gather some soil samples from the root areas of their oldest groves to try and obtain the mycorrhizal profile that can be achieved by growing bamboo among unaltered forests for years and years and multiply the number of infective propagules by the above method and then add the soil to next year's plantings and additions of soil layers to the existing bamboo.

Also, I am trying to think of a way to do an experiment to try and gauge what the effect of mycorrhiza of different types may be on bamboo, though I am planning on giving that idea it's own posting.
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Re: Ground covers, green mulch, green manure

Post by Mackel in DFW »

I have no problem with what you are saying. What I was pointing out was that on a small scale, green manure may be more of a hassle than using actual manure. It's an established agricultural practice, however, but generally on a pretty large scale. If you're concerned about holding down soil on a slope because of a lack of roots, mulch will hold down runoff for the most part. Your idea sounds good, but note that the legumes will also pull out micronutrients and temporarily tie them up.

What I AM suggesting is that carbon may be more important than nitrogen and more of the limiting reagent which is contrary to everything one experiences or reads. I am doing large nitrogen application only once this year, in spring, in the form of fish and blood meal.

Instead, I have been focusing on keeping the soil rich in carbon and micronutrients this year, rather than nitrogen, to test my hypothesis that the plant will requre less watering and overall fertilization, with this approach.. That is becuase high nitrogen burns up organics in the soil, regardless of what form it comes in. Nitogen can cause a drastic shift in the microflora toward high carbon and nitrogen consumption mode (loss of organic material). This has been shown to be true in test after test after test in agricultural soils.

Carbon, short for organic material, helps the soil retain water, air and nutrients and is perhaps a more indispensible ingredient than nitrogen, and that is my hypothesis. We know, in fact, that in nature much of the nitrogen is supplied in small doses by rainwater, and not by dead animals decaying into the soil, and that soils if left alone become rich in organics in part because there is not an excess of nitrogen eroding the organic material within the soil.

Hence, my statement that green manures may be more important in introducing organic material and air channels deep into the soil, than it's other function of adding nitrogen. Rain water has nitrogen, and when we add a lot of nitrogen to soil, it just may be the case we are setting up a vicious cycle. Supplemental nitrogen, I am adding at no greater than one percent, as I'm interested in a very stable microflora that steadily supplies nitrogen to the plant, and hopefully I am right that in the case of plant nutrition, the tortoise beats out the hare.

My hypothesis is based on observing how nature actually works. The approach also lets the plant focus more on adaptation to the external environment, rather than the internal (soil), which should make it tougher and more disease (external factors) resistant. I got much of my inspiration from listening and reading Howard Garrett, a local organic guy that is one of the few that doesn't sound like a new age earth worshipper, which is not at all me or explains my interest in organics and optimum plant nuitrition ideas.

Good results so far, and I am only watering when it is apparent in our 100 degree summers, that the bamboo is in fairly severe water stress. So, I have given up on a watering schedule, and have learned to "read the tea leaves". The bamboo quickly recovers, rinse and repeat. The longer it goes without watering, I chalk it up as an "empiric" victory. It's been fun to tell you the truth, trying something completely different and not because I am a tree hugger, actually I'm to the right politically but that's an unrelated topic, I post about that sort of nonsense somewhere else..


Regards,
Mackel in DFW.
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Re: Ground covers, green mulch, green manure

Post by Mackel in DFW »

You might also be interested in my other experiment, not really an experiment because I don't have a control population to compare it to, but I am using a bioinocculant called "Thrive" from a Kansas company. I've done this twice this year so far, and I mix it with molasses before spreading it out. Bottom line, my main goals this year are less watering and a tougher plant. I may not be seeking maximum yield per se, but I am seeking a sustainable way to grow bamboos other than the ubiquitous aurea, a proven winner here, in the overall hottest metropolitan area in America. In ten years :D I should be able to exhaust every idea, and experimentation can be part of the fun in growing bamboo. Often, simplicity seems to triumph over complexity.

Regards,
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Re: Ground covers, green mulch, green manure

Post by needmore »

Dallas is hotter than Phoenix?
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Re: Ground covers, green mulch, green manure

Post by movenosound »

Mackel- I also have been approaching bamboo horticulture from a my ecological-based, or maybe some call it green, or organic, but I call it just creating the environment which the plant is going to grow best in. And not because my politics have me so far out into left field that it seems extreme even to me, I don't harbor any warm fuzzy notions about nature and being ecological, I am simply very interested in what I guess is the science of it, not from some moral or ethical high ground. I think that understanding all the microbes in the soil that feed plants and create healthy soil just seems logical. I think that the evidence that adding various chemical in the form of fertilizer and herbicides to soil is detrimental in the long run, though I also see the practice of organic methods and creating very healthy environments as being somewhat laborious and at times expensive in terms of cash and in terms of time, and not everyone can afford to do so, or has the patience to. I think that in the near future the economics of these things will switch, and adding chemicals will become too costly, and not just in terms of cash, and these organic methods will be the standard.

I have been reading pretty intensely on three subjects that fit this category, those being mycorrhiza, composting, and cover crops (especially rhizobia-forming legumes). Each of these subjects has led me to read a small amount on the subject of nitrogen cycling, though I do not fully understand it yet. I think that your plan raises some great questions, especially the idea that carbon should be present in higher amounts alongside a decrease, or at least a lack, of supplemental nitrogen.

Weird coincidence, after I read your post, I also came across an article from the local business journal that had a local orchardist who has started a mid-size compost experiment, and in the article he too mentioned the idea of a high-carbon compost resulting in a higher population of fungi in the soil, and thus benefiting the plants and trees.

The part of this that raises a question to me is in the part about the higher fungal populations being good for plants. The beneficial fungi in the soil that help plants are mycorrhiza, and I believe that other fungi help mainly by breaking stuff down, which they pretty much do in the compost pile. Unfinished compost would release material over a longer period, because some of it still needs to break down, but there is the whole notion of N immobilization. I know that mycorrhiza receive the C that they use in trade with plants, the fungi offering up nutrients and water and a bit of pathogen resistance while the plant delivers some of it's photosynthesized carbohydrates to the fungi for it's source of C. So I don't know how the addition of extra C in compost would effect that relationship. The nitrogen added to a compost pile is said to be used as a fuel for the microbes that break things down into C parts, and so if you add unbroken-down things to a garden, then the microbes are still going to need to use N that is present to break stuff down. Are you saying that the N used by these microbes will become available later, after the microbes themselves break down?

This could bring to light some interesting things. Perhaps the chlorosis that we have been attributing to lack of N is actually due to something else? Maybe it can be attributed to an overall lack of nutrients, maybe the scale of micro nutrients? I know that adding too much nitrogen can acidify the soil, and that having ph levels too high or low can lock up nutrients in the soil. Maybe the addition of nitrogen in huge amounts is actually a way of combating alkaline soils and thus releasing locked micronutrients to the bamboo?

I am very interested to learn what your results are. I think we should compare results. I have been adding supplements to my plantings, usually in the form of earthworm castings and meals; blood, bone, alfalfa. Also add nigh nitrogen bat guano, and manure. To the compost I have added alfalfa meal and a little blood meal, and maybe a little guano, and lately I have been experimenting with molasses added to a compost pile at make-up to give it a kick in the microbe department and raise the temp. I have also read something about adding unprocessed vegetable oil around the same time, for basically the same reason, though I have yet to find another reference that can recommend this, so I have yet to do so.

I have been irrigating pretty heavily, and have actually had to cut it back a little. After leaving to go down to California for work, I returned to find that I had planted alfalfa among the plots instead of more clover, and so the bamboo had three foot tall plants crowding them out. My friend had taken my advice to let the cover crops establish a bit before cutting back to ground cover size, and he did not realize that alfalfa was starting to bum rush the plot. When I began to cut it back, I found that the thick growth of legume was sealing in cool air and moisture in the soil surface, and I feel that we nearly soaked out the incense and nuda. Now the temps are hovering around 100 degrees, and the covers are way back, so the water is back on.

I want to re-recommend that article about glomalin to you, I linked to it in my last post. For the topic of C sequestration it is really eye-opening stuff. A third of all soil C, in fungus glue, everywhere, for anywhere from 3 to 40 years, that is just intense.

Glomalin extracted from soil:
Image

Soil with all organic matter removed:
Image
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Re: Ground covers, green mulch, green manure

Post by Mackel in DFW »

To MOS-

I promise I'll do some of your suggested reading.


To Brad-

Sand is an insulator/reflector of heat, so deserts in general tend to cool down at night due to a smaller heatsink.


Regards,
Mackel in DFW
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Re: Ground covers, green mulch, green manure

Post by movenosound »

Also, Mackel, there is a scientist in Oregon who focuses on the whole dynamic of soil microbes and the movement of nutrients and materials into and out of the soil. Her name is Dr. Elaine Ingalls, and she promotes the idea (not sure if it is hers) of the 'soil food web'. I haven't read anything by her yet, though she endorses a book called Teeming With Life I believe, which covers this subject, and which I have been meaning to give a look to. Besides promoting this idea, the company Ingalls started promotes composting, and is really big on compost tea, and provides soil testing.

I am just going to keep adding as much organic material to the soil as I can, and hopefully the environment I provide will be conducive to good microbial health. For the time being, I am more concerned with building up a healthy soil layer of sixteen to eighteen inches on top of the very rocky hillside I am growing the bamboo on. Maybe once each species of the five has covered at least a thirty-foot diameter grove, I will begin to fine tune the soils, the composting, and whatnot, or maybe sooner, but right now I need SOIL!

Last year the spread of rhizomes on the atro that I planted in May was at least seven feet in one direction, and possibly three feet the other way, and that was well before end of season, so perhaps a spread of ten to thirteen feet. If any of the species decide to do anything like that this year, then I need to get cooking on the new soil layer.
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Re: Ground covers, green mulch, green manure

Post by dudley »

i sometimes wonder if our attempts to create these amazing nutrient rich soils is actually the way to go.my soil here is sand and all the native plants have evolved to deal with that.they actually thrive in soil with close to zero organic matter.everything from the speed of growth to the way they uptake nutrients and water is influenced by that.if i were to take my native long leaf pines as seedlings and plant them in an ultra rich soil they might grow faster but in the long run the tree would probably be inferior as far as wood strength, ability to handle drought, and resistance to blow over in high winds.
most of the plants we grow are not native and so the fertilizing and such becomes necessary(collards i dont fertilize are only 1 foot tall after 3 years because they did not evolve to handle my conditions)
but all you have to do is look around and there are dozens of plants that thrive in the same condition.
maybe if I researched my bamboos native soil and recreated it i could encourage better growth and not have to spend so much time and money refertilizing, and adding organics over and over and over.
i suspect that even disease and insect resistance might increase.
just speculation on my part though.
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Re: Ground covers, green mulch, green manure

Post by movenosound »

Found a pretty cool guide to managing soil organic matter on farms, along with some other pretty good books on organic farming methods, put out by the University of Wisconsin-Madison. They are available free online in PDF format. Here is a link to the direct download:

http://www.cias.wisc.edu/wp-content/upl ... orgmtr.pdf

Also the Sustainable Agriculture Research and Education program, part of the Department of Agriculture, has a page with some really informative publications. Two that I am reading now are Building Soils for Better Crops and Managing Cover Crops Profitably, both of which have a lot of information that is very easy to distill down to the level of a backyard or acre-size bamboo gardening. I think of Farming as Large Scale Psychotic Gardening, and Gardening as 'personal agriculture.' These books are available in PDF on this page:

http://www.sare.org/publications/handbooks.htm
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Re: Ground covers, green mulch, green manure

Post by canadianplant »

I just finished reading "Gaias Garden: A Guide to Homescale Permaculture". SO ive just been introduced to the idea of nitrogen fixing plants.***** I would recommend this book to ANY gardener..

From what ive read clover is one of the best, its not only a nitrogen fixer, its a very good living groundcover, which flowers attract benificial insects to your yard. Worms, and other microbes will love the cool and shade underneeth, and will reward you with some really good soil.

Have you tried comfery, despite its reputation for being highly invasive? IT has more uses then clover over all.

As for nitrogen fixing plants... Anything related to the pea family, lupin, wisteria, beans, peas, siberian peashrub ( which is also a great bird habitat, and bees live the flowers, and the pea pods are edible, and a great feed for animals.

There are other types of tree or large shrub that are notrogen fixers, such as autumn and russian olive, and almond if i remember correctly.

Any plant can be used fer multch, personaly, im going to plant some Miscanthus, and use it as a multch. I am also not going to clean up the beds at all in the fall or spring, but leave the dead plant matter all year. This lets all the nutrients an such go back into the soil to be reused, instead of pulling iti out, and eventualy depleting the soil.

Another trick he talked about, was planting densly, so that weeds or unwanted plants dont even have a chance to grow. This works good when growing using the "guild" method- Planting plants that would be around in the main plants natural setting. A good example of this... is Trachycarpus Nanus, from Yunnan China. The guy who runs RPS, rediscovered this palm growing in pine forests in the mountains, along with a "scrubby bamboo". Everytime he seen the Trachy, he seen this bamoo. This may attract pandas, which deficate, and fertilize the palm, or attract animals, such as goats to the palm, to fertilize the bamboo. So a guild in this case, would be the native pine tree, the bamboo, and the Trachy. Each plant benefits from one another.

What im trying to do personaly, is create something if a guild, with my Phyllostachys Aureosulcata. With a bit of reserch, I found that , Bleeding heart, Lilim, Weigela and many other common garden plants are all fromt he gerneral area as the Phyllostachys.


There is another way to create a good ground cover as well, but it doesnt fit into out preconcieved "perfect" clean and organised garden. Let me just say this: Show me a place in nature, that is as tidy as our gardens? I bet you really cant find it. In nature, there are plants called pioneer plants, dandalion, clover, and other "weeds" are these. When you have bare soi, and plants pop up, these are pioneer plants. These get the soil ready for larger perennial herbs, and other perennial plants, which start to choke ou the "weeds". Then the smal and large shrubs come, which bring more beneficial animals, which in turn created better soil. Then the large trees start to bloom, casting shade, and eliminating even more "weeds". I guess what Im saying, is to leave things alone, and let nature take its course. This will eliminate almost all need for weeding, and less watering, as well as a plethora of beneficial insects, and awsome soil, filled with a foot layer of humus eventualy.
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