plant type as compost ammendment
Lets say you wanted to add certain nutrients to compost by growing certain types of plants to add to your compost. Is there an authoritative guide that list plant type and expected or possible nutrient value when added to compost. And I do know this differs based on the state of growth in which the plant is composted and weather or not its composted right after fresh cutting or after it has dried out etc.
Pretty much if you know what the plant is high in that is what it will add to the compost.
Comfrey and borage are alkaline and add calcium to the compost. Comfrey is the only plant I know of specifically grown just to add to compost
Citrus fruits are acidic
bananas, papaya, acorn squash, beans, potatoes, and green leafy vegetables are high in potassium
Nitrogen rich ingredients are the greens, grass, green leaves
Green manures like cowpeas, alfalfa, sun hemp, clover, hairy vetch, sorghum, buckwheat add biomass, the legumes will also add nitrogen but that only for the ones that produce nitrogen fixing nodules and then are tilled into the garden at flowering.
We did test our finished compost it was alkaline because most of the nitrogen was gone, it was high in phosphorus. Since we add kale, gynuura, and comfrey to it often it was high in calcium (also adding to the alkalinity). The rest of the numbers were within range.
I don't think it matters much what you add as long as you get your ratio of greens, brown, and water right and it is best to use a variety of greens rather than from a single source. The NPK of compost even under the best of conditions is low. The true value of the compost is that it feeds the organisms in the soil and ultimately it is they who convert most of the elements into nutrients for the plants.
What might make a difference is if your soil is already very high in some elements. Phosphorus in particular can be very high and take years to come down. Organic nitrogen sources like manures and composts can be high in phosphorus, so you may need to balance the good it does vs the harm.
Comfrey and borage are alkaline and add calcium to the compost. Comfrey is the only plant I know of specifically grown just to add to compost
Citrus fruits are acidic
bananas, papaya, acorn squash, beans, potatoes, and green leafy vegetables are high in potassium
Nitrogen rich ingredients are the greens, grass, green leaves
Green manures like cowpeas, alfalfa, sun hemp, clover, hairy vetch, sorghum, buckwheat add biomass, the legumes will also add nitrogen but that only for the ones that produce nitrogen fixing nodules and then are tilled into the garden at flowering.
We did test our finished compost it was alkaline because most of the nitrogen was gone, it was high in phosphorus. Since we add kale, gynuura, and comfrey to it often it was high in calcium (also adding to the alkalinity). The rest of the numbers were within range.
I don't think it matters much what you add as long as you get your ratio of greens, brown, and water right and it is best to use a variety of greens rather than from a single source. The NPK of compost even under the best of conditions is low. The true value of the compost is that it feeds the organisms in the soil and ultimately it is they who convert most of the elements into nutrients for the plants.
What might make a difference is if your soil is already very high in some elements. Phosphorus in particular can be very high and take years to come down. Organic nitrogen sources like manures and composts can be high in phosphorus, so you may need to balance the good it does vs the harm.
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rainbowgardener
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Second imafan: The NPK of compost even under the best of conditions is low. The true value of the compost is that it feeds the organisms in the soil and ultimately it is they who convert most of the elements into nutrients for the plants.
when you are doing organic gardening and composting, you are not doing chemistry, you are doing biology. Nothing is so simple as saying this plant adds these elements to the soil. Everything you are dealing with is dynamic processes, constantly in flux. And the compost does not directly feed the plants, it feeds the soil web which feeds the plants.
"why couldn't a person make a basic compost, do a soil test on it, log that, compost something with it, retest and
then figure the results to see what nutrition was added" Because for example, putting a given plant in an active compost pile is not the same as putting the same plant in a bunch of finished compost. The finished compost is much less biologically active. Also the same kind of plant may vary widely in its nutrient make up depending on the conditions in which it was grown.
when you are doing organic gardening and composting, you are not doing chemistry, you are doing biology. Nothing is so simple as saying this plant adds these elements to the soil. Everything you are dealing with is dynamic processes, constantly in flux. And the compost does not directly feed the plants, it feeds the soil web which feeds the plants.
"why couldn't a person make a basic compost, do a soil test on it, log that, compost something with it, retest and
then figure the results to see what nutrition was added" Because for example, putting a given plant in an active compost pile is not the same as putting the same plant in a bunch of finished compost. The finished compost is much less biologically active. Also the same kind of plant may vary widely in its nutrient make up depending on the conditions in which it was grown.
During the decomposition process most of the nitrogen added to the compost pile is used up or taken out either through volatization, denitrifying bacteria, microbes in the compost that use it for food, and through leaching. By the time it is finished, unless you added a lot of nitrogen, most of it is gone or in the bodies of the microbes.
We tested compost a couple of times. It varies depending on your feed stock. So no two compost batches will be exactly alike unless you add the same components in the same amount. Even if you could do that, there will be some variation from plant to plant and in different seasons. Generally, the pH, and basic phos and K will be about the same. You are talking about numbers in the 1-2 range.
Compost does more than supply nutrients. The organic matter helps the soil to hold on to moisture, feed the microbes living in the soil, add air (at least temporarily it does fluff the soil), and organic matter helps to buffer the soil pH.
The best things you can do for the health of your soil is to
keep adding organic matter to feed the soil
Plant a variety of crops and preferably balance your rotation corn, a high nitrogen feeder, with beans which with inoculation and incorporation replace the nitrogen
Incorporate the crop residues from healthy plants. Recycle the nutrients.
Scientifically it is the conservation of matter. The principle that in any closed system subjected to no external forces, the mass is constant irrespective of its changes in form; the principle that matter cannot be created or destroyed.
The garden though is not a closed system. Some losses do occur as a result of harvesting, some are lost to other two and four footed critters, and some elements like nitrogen are leached out or back into the air (a bigger system than the garden). That is why organic matter and fertilizer is added to replace those losses. The real trick is to only add what is needed. That is where the soil test can really help in determining what is needed. What came out of the soil went in to the plants, so recycling the plants back into the soil it came from replaces some of what was taken out.
If you grow a crop of beans and you eat the beans and pull the plants and either throw it away or compost it, those nutrients that went into the beans will be lost to the ecosystem of the soil it came from. You replace that with compost and fertilizer for the next crop. If you don't over time the systems losses will result in less crop productivity.
We tested compost a couple of times. It varies depending on your feed stock. So no two compost batches will be exactly alike unless you add the same components in the same amount. Even if you could do that, there will be some variation from plant to plant and in different seasons. Generally, the pH, and basic phos and K will be about the same. You are talking about numbers in the 1-2 range.
Compost does more than supply nutrients. The organic matter helps the soil to hold on to moisture, feed the microbes living in the soil, add air (at least temporarily it does fluff the soil), and organic matter helps to buffer the soil pH.
The best things you can do for the health of your soil is to
keep adding organic matter to feed the soil
Plant a variety of crops and preferably balance your rotation corn, a high nitrogen feeder, with beans which with inoculation and incorporation replace the nitrogen
Incorporate the crop residues from healthy plants. Recycle the nutrients.
Scientifically it is the conservation of matter. The principle that in any closed system subjected to no external forces, the mass is constant irrespective of its changes in form; the principle that matter cannot be created or destroyed.
The garden though is not a closed system. Some losses do occur as a result of harvesting, some are lost to other two and four footed critters, and some elements like nitrogen are leached out or back into the air (a bigger system than the garden). That is why organic matter and fertilizer is added to replace those losses. The real trick is to only add what is needed. That is where the soil test can really help in determining what is needed. What came out of the soil went in to the plants, so recycling the plants back into the soil it came from replaces some of what was taken out.
If you grow a crop of beans and you eat the beans and pull the plants and either throw it away or compost it, those nutrients that went into the beans will be lost to the ecosystem of the soil it came from. You replace that with compost and fertilizer for the next crop. If you don't over time the systems losses will result in less crop productivity.
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toxcrusadr
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Of course we do know some of that info, such as manures being fairly high in phosphorus. NPK is not all that hard, but if you want to get into minor nutrients (Ca for example) and micronutrients (Fe, Mg, Mn, Cu etc.), that's a lot of analysis.
Getting detailed data on a large range of plants not a bad idea theoretically, but in practice, it would be very expensive to do all those tests, for limited gain. I say limited gain because most gardeners compost what they have available at any one time. It's not like you can go out and find a cubic yard of comfrey when you want it. If you could it would not likely be free, so the cost of making 'nutrient managed' compost would be high. Therefore, having detailed nutrient info for various feedstocks is not likely to benefit the average gardener.
Not only that, but what your garden may need will vary by soil type, climate, what you grow and how much you harvest, what you use for amendments, etc. So there is an *endless* variety of situations, combined with an endless variety of compostables. A complex system that would be very time consuming and expensive to manage at this level.
Luckily, composting and gardening is very forgiving. Plants do well within a range of conditions. Over time, as you compost various materials and add the compost to your soil, you get an 'average' nutrient addition, which is a good thing. Clearly the system works as is, and the only time you really need to pry into the details is if you have a major growth problem due to a nutrient deficiency.
Amazing how nature can pull off growth and productivity in a system so complex it would take a huge amount of effort for us to describe it mathematically.
Case in point: The Bio Dome, an artificial habitat created a few years ago, which several people inhabited for some months, totally enclosed. After less than a year, the ecosystem began to collapse, air quality declined, nutrients were unbalanced, insects got out of control. Millions were spent developing it, and all that money could not create an artificial ecosystem that could support six people for even one year. Think about that.
Getting detailed data on a large range of plants not a bad idea theoretically, but in practice, it would be very expensive to do all those tests, for limited gain. I say limited gain because most gardeners compost what they have available at any one time. It's not like you can go out and find a cubic yard of comfrey when you want it. If you could it would not likely be free, so the cost of making 'nutrient managed' compost would be high. Therefore, having detailed nutrient info for various feedstocks is not likely to benefit the average gardener.
Not only that, but what your garden may need will vary by soil type, climate, what you grow and how much you harvest, what you use for amendments, etc. So there is an *endless* variety of situations, combined with an endless variety of compostables. A complex system that would be very time consuming and expensive to manage at this level.
Luckily, composting and gardening is very forgiving. Plants do well within a range of conditions. Over time, as you compost various materials and add the compost to your soil, you get an 'average' nutrient addition, which is a good thing. Clearly the system works as is, and the only time you really need to pry into the details is if you have a major growth problem due to a nutrient deficiency.
Amazing how nature can pull off growth and productivity in a system so complex it would take a huge amount of effort for us to describe it mathematically.
Case in point: The Bio Dome, an artificial habitat created a few years ago, which several people inhabited for some months, totally enclosed. After less than a year, the ecosystem began to collapse, air quality declined, nutrients were unbalanced, insects got out of control. Millions were spent developing it, and all that money could not create an artificial ecosystem that could support six people for even one year. Think about that.