I see your point and agree in terms of leachable nutrients. OTOH, humus can and does build up and is relatively permanent, at least compared to nitrogen. I would certainly take the 'cows' comment with a grain of salt if someone said that to me, but then I'd take a shovel and take a look. :-]

Change is the only permanent. If nutrient input is stopped the fertility will be gone too.

So, when someone does a soil analysis for organic matter in the deep, rich top soils of Iowa or southern IL, what do they find 8' down?

I like to imagine that my compost laced gardens attracted earthworms and that they remain there defecating and living on the corpses of their kind. The richest soil on this property is a lawn that my father seeded with night crawlers 50 years ago. I still come upon huge night crawlers here and I always imagine they're descendants.

Dave, I presume you mean that they find ancient OM 8' down, right? Indeed, the OM in bogs can be extremely old. Such things occur. It isn't because some ancient peoples made compost, however.

In the SE US archaeologists and some soil scientists have recovered and radio-carbon-dated humus material from deep soils. The dates go back thousands of years; wish I had saved reference to the article.

I've been adding farm-made compost to my vegetable fields for over 20 years and have grown many crops without additional fertilizers for some years. The heavy feeder get fertilizer as preplant with the compost. The deciduous orchard of mixed varieties have been surface composted annually and mulched with coarse wood chips for years, some for over 20 years, other more than 10 years. I am finding diminishing need to fertilize these trees, perhaps a quarter of recommended rates.

And we could mention the terra preta phenomenon in Amazonia. Apparently the evidence for a connection to ancient human activity is there. Was it achieved via Indore-type composting?

hi
interesting discussion but curious if this doesn't work what does?? "Permanent" is there such a thing?? Obviously if "recycling" was not taking place and obviosly rather stable
the world would be covered in dung and waste products ??
I must be missing your point?? gary

Gary, I'm musing about man-made compost. Obviously there are many decay cycles that operate and always have with or without human activity.

In nature, given enough time(like a few thousands of years) all nutrients of soil will be washed and leached away by rain into rivers and ultimately into the sea, and never the other way round. So it is safe to say that fertility of soil can be preserved because of human activities of farming, because we bring a lot of nutritious things out of the sea and utilize them in-land so the whole circle of soil nutrient can be maintained. Even the terra preta thing, if left to be weathered enough for a long enough period, will become nutrient-depleted like a desert.

"In nature, given enough time(like a few thousands of years) all nutrients of soil will be washed and leached away by rain into rivers and ultimately into the sea, and never the other way round."

Right, but we can and do take advantage of that by using the fertility where it accumulates on that journey: bottom-lands.

Of course there are some very powerful forces that counter leaching/erosion, namely volcanic action and glaciation.

I'm thinking about buying some ocean in part of the world where the sea bed is rising. In a few million years I might have a nice piece of fresh land with all the nutrients I got from the rest of y'all. :-D

A phenomenon I see around here is the long-term physical geography changes and ecosystems set up by beaver dams - the actual structure is barks, sticks, and mud holding it together, maybe a rudimentary compost. They also build little mounds of underwater twigs/barky bits of wood - another form of rudimentary compost, and the dams catch a lot of silt and organic matter that washes in.

Could one consider a beaver dam, over, say, 100 years, one big compost pile?

This all builds up and flattens out the stream channels and creates productive meadows. But the real action is in the aquatic food chain - Its amazing how much fish biomass these undisturbed systems can hold.

". I think there is an idea that compost and manure can "build up" soil to such a level that it is permanent fertility for human food production"

Pnbrown, you do make a good point.. You need constant recycling/decomposition of nutrients in order to have a healthy garden.

"It's worth noting that soils do not accumulate "naturally" via compost piles. Very few animals other than humans make piles of OM in such a way as to experience heating from thermophyllic microbes."

Another very good point.. So, are you inferring we should find other more natural ways to build/mantain soil? So where in nature does constant nourishment/decomposition occur? Several places. The first that comes to mind is a forest, with a nice blanket of leaves and decaying wood. Should we try to mimic nature and compost on top of the soil?

Indeed, mature forests seem to sequester and cycle nutrients in a nearly stable system. And even immature ones may.

However, if we try and grow our common crops directly in forest duff in little clearings we will likely find production is very poor. Nutrients are not in sufficient supply for most annual crops in such systems. Often Ph will be out of range in these natural systems.

Adjusting macros and micros, planting crops and providing fertilizer on occasion, while keeping a constant mulch on the ground is not at all "mimicking" a forest.

Don't forget that we, the humans, are also part of the NATURE, some of the hands of the nature. So whatever we do is also NATURAL. We take advantage of our bigger brain and higher intelligence and do/make things that benefit us in much shorter time frame. I am all for science and human ingenuity. Some of the things we do might be harmful to us in the short run but in the long run things will be corrected and their benefits outweighs the harms.

JMO

Your approaches to these issue are too "conventional", as in conventional, scientific chemical agriculture. You forget that most of life exists in the rhizosphere, billions of organisms dancing a life's rhapsody in ways were are just beginning to discover. NPK is a human construct.

Everone knows that.

Well did you know momma alligators were systematicly making compost for over 2 million years before humans did so ?

There is a great misunderstanding about the fertility of forest soil(at least some of the forests). I live in a tropical rain forest. The soil here is definitely nothing like what one would assume a forest soil should be. The word "rain" in the "rain forest" will give you some idea about the nutrient leaching rate of the soil here. With such frequent flood and sandy soil texture, what is left in the soil simply cannot amount to much in terms of agriculture.

Soil nutrients do not simply fall down from the sky with the rain. Of all the 16 essential soil elements required by plants for optimum growth, how many of those can withstand thousands and thousands year of rain?

Yeah, I think I saw the same tv show about the mother alligators :) And point taken about beaver dams.

Ceth, at least a couple of nutrients can fall with rain (and more with snow), S and N. As we know, C comes from the atmosphere and so can N. The ability of those to remain near the surface of the soil largely depends on soil type, I think.

Seysonn, yes, humans do what they do. One of the big things we have done is breed food plants that do not thrive in 'natural' conditions. That is mainly my point here.

Marshall, I'm not sure if you were talking to me or someone else?

Pat, mine was a general reminder. We humans are "edge creatures" adapted to and replicating disturbed habitats. As our technology grew, we proceeded to eliminate as many competitors as possible and replaced them with useful replicants: farm animals the crop plants, for example.

Now we are in the age of engineering the microbial base of life for our benefit.

Seysonn, yes, humans do what they do. One of the big things we have done is breed food plants that do not thrive in 'natural' conditions. That is mainly my point here.
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We, the humans, have always fought the elements that are unfavorable to us and have created ways and means that benefit us more and faster (from bare foot to the jet planes ..). Composting is just a small portion of that. Discovery of NPK, cholesterol, .. have been great advanced we have made.

My point/views, might be unconventional in the common convention but its is part of a new greater science -based philosophy . To say that, eg, honey made by the bees is NATURAL but if we make syrup from corn is UNnatural is not correct. Realizing that we have a short life, we the humans, speed up the things to make it happen in the short run, because, in the long run we all be dead.

Natures_Nature says " So where in nature does constant nourishment/decomposition occur? Several places. The first that comes to mind is a forest, with a nice blanket of leaves and decaying wood. Should we try to mimic nature and compost on top of the soil?" and Mr. Brown agrees on the forest system! Where some who have tested forest soil and found it seriously lacking in nutrients go wrong, is that they don't consider the mycorrhizal contribution - that is, in untilled soil, the network of mineral distribution that is more heavily spread beneath the soil surface than in cultivated land. This tends to even out the playing field, such that nutrients are traded between plants and fungi, the plants providing C, O, H and the fungi providing the other minerals from far and wide so that they are more abundant right at the plant's roots than anywhere in a given, small sample of soil.
I'm almost finished reading "Restoration Agriculture" by Mark Shepard. It is a sustainable approach, and continually points out that "modern", annually-planted agriculture, is very inefficient compared to a forest based, sustainable agriculture that includes some surrounding grassland. With annual planting, not only does the soil start out bare at Spring planting, and continue mostly bare even when solar energy is maximum in June, thus converting very little energy into useful and marketable crops, but in order to even start a planting of annuals, a whole, natural ecosystem had to be completely destroyed (prairie or forest). This system was multi-layered, and had a huge number of mammal, insect, reptilian and bird species that continually enriched the soil. All this is gone in modern agriculture. Thus, yes, we need compost.
Shepard's book hasn't convinced me to abandon my garden of annual vegetables, but it has made me thankful that I have pasture, grapes, chestnuts, pecans and blueberries growing around the place, and that I have a functioning woodlot that is a great resource that actually can be improved in efficiency if I introduce some other crops in the understory. The whole idea of restoring some land to forest is worth looking into. Forests can also feed pigs, sheep, turkeys and chickens, and they will in turn feed the forest.
Glenn

Glenn, I didn't read all of your post due to the lack of paragraphing.

You seem to be saying that a forest is a fine example of a place to grow our common food crops. Have you tried it? I don't know about where you are, but around here there would be a number of problems that would limit production severely. A few crops might do well in little forest clearings - notably sun choke.

Also, mycorhizzial fungi exist in many soils, not just in established forests.

Pat, I haven't (yet) tried any changes to my land to incorporate the ideas of the book I mentioned. It's all laid out there in Mark Shepard's "Restoration Agriculture". It's intriguing though. I recommend it.

As I said, I haven't even finished the book. But Mark is "living" his plan on some acreage in Wisconsin. As any alternative, sustainable, carbon-minded farmer would do, he bases his book on proof that what we (meaning American Ag. in general) have with our annual crops of high-carb, nutrient poor foods is basically a lose/lose, cheat the Earth system. I like his approach, but am not ready to give up my garden of annual veggies yet! I may plant berries at the edge of my woods though!

No, I (as well as Mark) am not saying to grow our common crops in the forest. It's totally different crops he suggests. A total life-style change for the farmer, which conserves minerals, water, fuel and human effort, with better production than we get from our monoculture of annual crops.

As I see it, and as he depicts it, there's no down side except the farmer must look at many things, instead of just a planting, cultivating, spraying, harvesting schedule. It takes a bit of intelligence, just as heating with wood (in my other discussion with you) takes more intelligence and planning than just setting a thermostat. It doesn't make a system wrong just because it is different.

Yes, I used that fungi argument as a preempt on the argument that forests generally exist on poorer land than what we use to grow annual crops now. All I wanted to say is that a normal soil test can find deficiencies in a forest soil which actually don't exist right at a tree's roots, thanks to mycorrhizae providing sometimes an abundance of minerals right in the roots. And of course, this can happen in any environment, but is more limited the more plowing and poisoning that is done.

I'm in S. Carolina, right at the edge of zone 7b / 8.

Glenn

Glenn, thanks for re-organizing.

I don't find anything to disagree with in what you have just written, in fact it is all along my own lines of thinking.

I think Mark Shepard is the guy who is growing hazelnut and chestnut food-forests in a big way? A number of people here have read the book and have talked with him, I believe. And bought trees from him. Sadly our soils here are very poor and thin compared to most soils in WI or most other regions, for that matter - whether forested or not. It sounds like a good book, I think I'll read it soon.

Pat, I am not sure in which direction this thread should go, but there is one natural soil which is germane to well kept agricultural soils, and that is alluvial soil. Nile Valley, Sacramento delta, but even where I grew up, fat heavy rotting muck, with so many layered deposits as to make it look like its fertility is permanent, perhaps with the exception of nitrogen. A small fraction of the world's cultivated area, no doubt.

Indeed, alluvial soils are the bomb. Maybe someday I'll get to use some..

Unfortunately, with rising sea levels and the growing frequency of flooding, these deltaic features will not likely be available without major engineering projects.

That's true. Earlier deltas upstream exist, I suppose. Plus the bottomlands on most river systems.

Maybe another way to look at this is concentrated nutrients.

I have a raccoon latrine on the far side of the pond - imagine the concentrated nutrients that add up over a few decades.

Right now we're having a wind storm, blowing leaves and dust, accumulating the two in any hollow or spot the wind is less.

For that matter, the whole western half of this county is loess soils, dust and organic matter blown in from the SW deserts.

I know this is a few months old but deserts actually have some of the most fertile soils in the world, chock full of nutrients because there's no water to leach them out. The reason most of them seem so lifeless is that they are limited by the amount of rainfall they receive, so the nutrients are locked in the soil. If you go out to the desert after heavy rains you'll see all of the plants spring to life and flower since they were waiting on the rains to make the nutrients available.

On the other hand, the equatorial rain forests have some of the most barren soils in the world. All of the nutrient value is stored in the vegetation and cycled on the soil surface. Chop down a stand of trees and try to grow crops there without adding in a lot of fertilizers (natural or synthetic) and you won't produce much. Let that plot lay fallow and it will never return to its former glory in our lifetimes, or our descendant's lifetimes.

Yes, that is why growing crops in the desert with fossil-water is huge business: the very mineralized soils grow great plants with less fertilizer, and the dry air reduces mildew problems and some other diseases, as well as generally lower pest pressure overall.

"Chop down a stand of trees and try to grow crops there without adding in a lot of fertilizers (natural or synthetic) and you won't produce much. Let that plot lay fallow and it will never return to its former glory in our lifetimes, or our descendant's lifetimes."

In my experience working in Latin American tropical forests that last statement does not really ring true as far as the old traditional slash and burn agriculture was concerned. With nothing but hand tools the people would clear not much more than a couple of hectares (5 acres more or less) at a time, burn the slash, plant crops like corn and beans for maybe a couple of cycles and then move on to clear more. Nature may abhor a vacuum but in the tropics it REALLY abhors bare land and pioneer species leap in to cover it. Within a few years more tolerant secondary tree species establish under partial shade, and by fifty years or so you'd see a new multi-species, multi-storied forest where once there had been bare land.

Today, where machines do the clearing and wipe out vast areas at a time to establish grass, you are right. It will take a long, long LONG time to recover, if indeed ever. How long is ever, by the way?

everything decays-everything returns to the biomass-composting merely accelerates the process-to claim that one part is more natural, more real, than another is to be blinkered by anthropocentrism. as for forests not regenerating in a lifetime go online and look at photos of abandoned farmland east of the miss. when the farmers go away the trees come back immediately.nature and the earth are a lot more powerful than we are-if something has to go it will be us.

There is a lot of talk about forests recycling nutrients, but of course a prairie does too. This may have been mentioned as well, I haven't read every word of the thread. Our goal might be stated as, rather than emulating a forest, to try to achieve sustainability by putting in as much as we take out of the soil, with minimal fossil mineral or fuel inputs, regardless of what or where we're growing.

One way in which we could do better is the disposition of manure, both human and animal. Confined feeding operations, for example, at least in the US, treat waste with the goal of minimizing it (making it go away) as fast as possible. So a waste lagoon gives off a huge cloud of nitrogen containing gases, which in some places fall back on waterways and pollute them when it rains. Then the remaining material is spread over much too small an area of farmland. If we went back to spreading manure before half the nitrogen is gone, over a larger area, the soil would benefit.

Same is true for municipal wastewater treatment plants.

If we saw this as nutrients instead of waste, the soil would be better off.