How do we maintain adequate phosphorus and potassium levels for crops?

How do we maintain phosphorous and potassium fertility, as rock-based supplements become in shorter supply, and fossil fuels for mining and transportation become less available? A Penn State University website says:

Most forage crops remove between 15 and 20 pounds of phosphate per ton of hay equivalent and between 45 and 60 pounds of potash per ton of hay equivalent.

One way of maintaining fertility is not to remove plant residues in the first place, unless absolutely necessary. This study talks the importance of leaving wheat crop residues in order to maintain phosphorous levels. Burning biomass residues for heat or electricity or converting biomass to biofuels seems like a step in the wrong direction.

In this post, I will talk about a few ideas I have run across regarding maintaining phosphorus and potassium levels in the soil. I would like to hear what approaches you have been using.

According to the same Penn State website, manure is an excellent source of phosphorous and potassium. However, some plants may not need the nitrogen it supplies, and in fact, adding nitrogen to legumes "can greatly increase the competition from grass and weeds", according to the same website.

From Penn State website.

Clearly, if animal manure works, humanure would work also. According to this Energy Bulletin post, humanure is composed of 6% nitrogen, 4% phosphorus and 2% potassium.

Besides animal manures, there are various kinds of green manures. One I have come across recently is nitrogen fixing trees (NFT) which are trimmed, and the trimmings used as a green mulch. These trees seem to also provide phosphorus and potassium. According to Nitrogen Fixing Tree Start Up Guide:

In farm systems using NFTs, it is estimated that 100-1000 lbs. of nitrogen per acre (50-400 kg per hectare) are accumulated every year by the NFTs, depending on species, soil, and climate, Rhizobium efficiency, and management.

Incorporating nitrogen fixing trees in certain kinds of farm systems can enable the farmer to grow almost all of the nitrogen fertility necessary for crop production right on-site. Fertility provided by nitrogen fixing plants can promote healthy plants and soil life naturally. One study in Hawaii, for example, found that by using 15% of the land for NFTs, approximately 10 tons of mulch could be produced per acre per year, containing 185 lb nitrogen, 11 lb phosphorous and 72 lb potassium.

There seem to be quite a number of nitrogen fixing trees for various climates, including red alders, mimosas, and many others. Besides being used as a green mulch, NFT can be mixed in forest gardens to maintain soil fertility.

This organic gardening publication of the extension service of West Virginia University provides the following list of sources of phosphorus and potassium:


Sources include manure, bone meal, fish and poultry meal, and rock phosphate.


Sources include manure, alfalfa meal, kelp meal, greensand, wood ash, potassium sulfate, and granite dust.

Some of these will be more available long-term than others. The ones that need to be mined and transferred long distances would seem to be particularly at risk of disruption.

I found one letter to the editor at Scientific American (October 2009) intriguing. It is by Norman T Uphoff, Cornell University. It talks about the use of phosphobacteria for maintaining soil fertility. It says:

David A. Vaccari’s “Phosphorus: A Looming Crisis” usefully called attention to the critical role of phosphorus as a plant and crop nutrient and to possible future scarcities and constraints. But his focus on it as a fertilizer neglected its abundance in most soils. There is usually 10, 20, sometimes even 30 times more phosphorus in the soil than the amount in “available” forms that plants can readily utilize. The large amount of unavailable phosphorus is continuously, though relatively slowly, converted into available forms through the activity of soil microorganisms, many of which are known as phosphobacteria.

Without these microorganisms, plants could not have been growing in the earth’s soils for more than 400 million years. Ironically, the use of inorganic fertilizers can suppress roots’ and microorganisms’ production of the phosphatase enzymes that are essential for making phosphorus available for plant use. This inhibition is similar to the way that adding inorganic nitrogen to the soil diminishes the production of nitrogenase by plants and microorganisms to sustain their fixation of atmospheric nitrogen, which becomes available for plant nutrition. . .

I notice when I Google phosphobacteria, there are a number of websites that come up, selling such bacteria, such as this one. They seem to be mostly in India.


1. What approaches are you using for maintaining phosphorus and potassium levels?

2. How scalable are the approaches you are using? Could they substitute for the current rock-based fertilizers?

3. How do you deal with the issue of too many of some nutrients in manure--for example, for sweet potatoes, when you don't want the tops to grow too much, and for legumes, when you don't want to encourage the weeds?

4. Have you tried using nitrogen fixing trees? How about phosphobacteria? Is there an expert on either of these subjects that would be interested in writing a post?

5. Are you using humanure in your fertilization program?

6. Are there approaches I have missed?

Burning biomass residues for heat or electricity or converting biomass to biofuels seems like a step in the wrong direction.

It actually makes more sense to harvest biomass for cellulosic ethanol so that the potassium or phosphorus
can be chemically recycled/extracted for fertilizer. If you leave it on the ground it will end up in runoff and pollute the surface water as it does now.

It seems to me the phosphate from vegetable decomposition is a bit more likely to remain in the soil long enough for the next year's planting (compared to the soluble phosphate from an animal feedlot). Though your point that it may be feasible to recover phosphate from an ethanol operation is well taken.

Absolutely vital for understanding soil fertility and the issues of phosphates and nitrogen is an understanding of soil micro-organisms. I highly recommend this book, one of my all time favorites: Teaming with Microbes: A Gardener's Guide to the Soil Food Web.

Yeah that book is pretty good, but the authors are not soil scientists and it shows a bit. The copy I borrowed from the local library had the description of pH backwards.

Speaking of soil science, or any other peer reviewed science for that matter, It's a shame that all of the great journals of work funded by taxpayer dollars in universities is off limits for free to the taxpayer beyond a paywall of Elsevier or some such publishing house.

On my copy, page 41, the description of pH is perfectly accurate. You can see it at amazon by previewing the book too (click the link in my post above). Maybe you saw a very early copy ... ?

No, it is not perfectly accurate. The description of pH in terms of H+ ion concentration change as described on the bottom of page 41 is backwards in the Amazon edition.

It makes more sense to take the residue off the field for a non-existent process than reapply it to the field it came from? Sorry, don't agree. Do what you want with your own fields.

If you have that much phosphate/potash running off your fields, you need to figure out a better water management / fertilizer system.

Make no mistake, the cellulosic biofuel technologies are coming. There are dozens of cellulosic biofuel technologies that are being tested in pilot plants all over the world and many of those in the United States. In about 10 years, we will see many new cellulosic biofuel plants built which will be demonstrating these technologies. Some of them are likely to be very innovative designs which will be cheap to operate and can readily replace gasoline or diesel fuel.

So using the cellulosic material to make biofuels and returning the minerals back to the soil is a great idea for sustainable cellulosic biofuel production.


I have been excited about this possibility in the past, but I am now dubious.

How much water will be needed for this process? Where will this water come from?

To what extent will the source of cellulose be native grasses? If this is the source, how does the farmer protect against fire?

Even if the source is all from non-food crops, it will inevitably compete with arable land or pasture land that could be used for food production. How do rationalize feeding SUVs rather than people in a world where a billion some people are chronically underfed?

And a problem for all of those looking for new sources of energy for humans--we have not used the enormous amounts of energy that we have been bequeathed very wisely (vast understatement, that). If you are providing humans with more power, you are at least partly responsible for what they do with it, just as you are responsible if you hand a live chainsaw to a six year old.

Even before the effects of gw, humans powered by ffs, as well as some nukes and hydro, were responsible for the sixth great mass extinction, destroying habitats around the world and under the sea. How can you be sure that new energy will not be use to further such destruction?

Answer: You can't, and it will be.

Individually, many humans can be quite wonderful, but collectively we are more rapacious than swarms of locusts.

Everyone in this mini thread is mis informed on the relationship between nutrient retention and crop production in the modern world.

The absolute worst case scenario, from a nutrient standpoint, is what we are doing today.

Producing any grain (corn, soybeans, wheat, etc) and shipping that food away from where it was grown is the largest depleter of P & K from the land. By exporting food out of where it was grown your are exporting your most concentrated nutrients the plants have stored. The process essentially is mining the soil.

You want to be exporting only C,H,O,and N off the land. They are all replaced via gases in the atmosphere. A century ago most of the food was recycled where it was grown via animal or human consumption and waste. Not so today. Exporting food from the "interior" to the major cities on the coasts moves P & K away from productive land, essentially into water systems.

This is why some want to use much more arable land to produce liquid fuels, i.e C, H and O only for export. The nutrients then would be cycled back to the land where they came from. You break the export cycle which results in much fewer nutrients needing to be shipped in. A much smaller % of the base is needed for human and animal feed in the "interior".

The small problem with this approach is what do people be eat that don't live on highly productive land?

Perhaps they need to reconsider where they are living...

At least near the ocean, seaweed is a traditional source of plant fertilizer. It has been used in the past and will no doubt be used in the future. Actually, Acadian Seaplants in Nova Scotia is still making fertilizer from seaweed. They use FFs of course but unlike the Haber-Bosch process, their operation does not directly depend on FFs as a feedstock (before anyone else points this out, I know that the Haber-Bosch process can theoretically be run from renewables).

It is interesting that 5 years - to the month - after I learned about PO I am seeing this come up again. I learned about PO due to a high school project where I learned about why mining NPKs and flushing them into the ocean is not sustainable. I was much more worried by the NPK issue then because an industrial economy without oil is theoretically possible but NPKs cannot be conjured out of nothing.

As we begin using seaweed to fertilize our fields, and start allowing plant matter to rot in our fields..., I'd suggest we get serious with our population problem.

End all immigration.
Encourage other countries, such as India and Bangladesh, to follow China's one child policy.

Otherwise, we'll just be spinning our wheels.

"Bangladesh endorses one-child policy"

A little late in the game, non-enforceable (which doesn't mean it won't be effective), but nonetheless displaying intelligence and foresight.

Meanwhile, as birthrates fall and population ages, the world as a whole is on track for a population implosion.

Hi toilforoil,

I have a hard time feeling optimistic about studies that use birth/fertility rate to argue that population growth is no longer a concern. The real number is growth rate and the global population is growing. All the credible estimates I've seen put the global population at 9+ billion between mid and end of century.

Growth rate takes into consideration net immigration and death rates. If an affluent country has lower birth rate but lower death rate and uses immigrants for it's labor force - then the actual growth rate is still positive - as it is in the US.

9+ billion humans later this century does not sound like a comforting scenario.

I would like to see every country - starting with the US - adopt a formal policy regarding population growth. Hopefully, it would not be a policy that advocates having more people!

A few miles from my house a man maintains horses on his farm for wealthy cliental. The horses crap a lot. The farmer gives it away to my son who brings me several trailer loads a year for my garden.

The man with the horses is buying in fertility in the form of fodder for his horses. He is then exporting the fertility from his land and giving it to you.

To quote the song 'The very thing that makes you rich makes me poor'. It's not really a zero sum economy, because the slow break-down of bedrock which creates the soils in the first place and supplies P and K (and other essential minerals - magnesium, manganese, sulphur, various trace elements) will replenish supplies that are lost by erosion in natural ecosystems. But agriculture/horticulture/horseyculture take out far more than natural weathering and root activity can supply. Also, different bedrocks give different availability of plant nutrients. Some clays give rise to nutrient rich soils, sandstones generally rather poor soils, chalk and limestone may be rich or poor, but availability of nutrients is also pH dependent. So recycling of all nutrients is essential.

Recycling sewage is a priority. In rural areas this is/may be relatively simple. The problem is with cities and industrial areas (and half the world lives in cities) where sewage is contaminated and cannot be returned safely to agricultural land. In the UK sewage can no longer be flushed onto the sea, and increasingly (as we de-industrialise) it can be treated sufficiently well that it can be returned to the land, but more than half still goes to landfill.

great, important topic; thanks gail.

1. i use composted horse manure that is closeby. i started with hard clay so lots has been required;' on the order of 50 tons over ten yrs. this is for a 120x75 plot.

i also collected bagged leaves; several truck loads in beginning my enriching the soil process.

i have had 10 tons of sand added + small amounts of my chickens manure. i add wood ashes in moderation. i add some rock lime as our soil is too acidic.

2. with lots of fuel we could haul/load & manure available???? not really scalable on todays amounts of acreage, but ok on smaller scale with lots of work if limited/expensive fuel.

3. crop rotation for less nutrients; though this got my sweet potatoes one year.

4. no.

5.starting dog/humanure composting currently. used dog do straight around my one very old pear tree a few years- got good harvests.

6. none i know of . i'm all ears too.

The Humanure Handbook is at available at It is the most simple way I have seen and costs little to set up. You can collect urine separately and dilute and distribute daily to whatever plant you want to get a bit of nitrogen. Since most plants have a wide root area you can pour it near to the plant but not so close that you splash it on if you are squeamish.

We compost chicken manure with leaves as well and rotate, and get leaves in town. Feeding 100 chickens will likely eventually be impossible for us as well as driving to town for pre-bagged leaves. So I invested in a rake for when I need to gather my own leaves. By the time I am doing that my soil should be in pretty good shape.

First, why does burning the biomass for energy seem like a step in the wrong direction? If you reapply the ashes to the field, they contain the potash and some of the phosphorus in the original plant. If you let these materials break down in the field, you have to have a good source of nitrogen, since except for legumes, the plant residue has a high carbon/nitrogen ratio. Right now we're leaving most plant residue on the fields, but composting some of it with horse manure. We're in our second year of organic transition, so most of our residue right now is either legumes or some form of weeds.

However, we're starting to burn some of the woody wastes for heat, and returning the ashes to the field. The eventual plan is to char about 5% of the field residue and return it to the fields, and use some of the woody waste for wood gas to run equipment and char for the fields.

Our soil tests showed that we don't need phosphorus, but we bought and applied a good deal of rock phosphate before those tests. I suspect we're set for phosphorus for a while. The tests said we need potassium, however, so we bought a pallet of some OMRI-certified potassium sulfate. That clearly could be a problem in the future. We're applying a good amount of manure, mostly horse manure to deal with that in the long-run.

We do a small amount of humanure, which we apply to a comfrey patch, and put the comfrey in our compost piles.

We've planted a few dozen black locust trees and will be planting alder and more locust this year. Unfortunately, the deer have developed a taste for black locust this year.

I think the question with biomass is whether anyone will actually spread the ash in practice. Spreading the ash adds at least two additional step--transporting the ash back to the field, and then distributing the ash over the field. Both of these require fossil fuel and human labor, so add costs.

Does anyone have experience with an organization burning biomass for power, and then also taking the responsibility for sending the ash back and paying to have the ashes distributed over the field?

There are a lot of people burning wood for heat (and have over the ages). I doubt very many of them are distributing the ashes back to the fields.

The situation is worse than that. Ignoring trace elements, burning biomass drives off all the organic matter, all the nitrogen, most of the phosphorous, and some of the potassium. From a nutrient stand-point, the ash is only a pale shadow of the biomass you started with. Ash should be returned to the soil, but lets not mistakenly believe that doing so closes the nutrient loop.

Digesting bio-mass for the production of ethanol (pretty dumb) or bio-gas (less dumb), then burning the resulting fuel, are more attractive processes from a nutrient stand-point. They don't drive off nearly as much nutrients as burning bio-mass directly, but neither is a silver-bullet technology.

re burning or carrying off crop residues;

plants need air/oxygen and this can only happen if the soil is somewhat porous. this is one of the purposes of the biomass, to provide continuing 'loam' to the soil.

i was told the info on oxygen by an irrigation consultant who sized a system different than i wanted. Due to low well water capacity i wanted to max out the well by a little water almost all of the time. he insisted i needed a 'dry' cycle for the air/oxygen to get to the roots. i've not researched this, & would welcome more info. the 'drying cycle' made sense to me though, as a natural process.

Um, why don't you look up the nitrogen content of dry straw and firewood and get back to us? What carbon neutral fuel do you use?

And we should switch terms. I think most people hear 'biomass' and think straw or cornstalks. I don't know of anyone burning those things. I'm sure someone is, but I've never seen it. Most people burn biomass in the forms of wood or maybe corn cobs. I suppose I'm also biased in that I don't call it burning biomass when someone has a corn stove. That strikes me as burning food.

And if anyone thinks that significant amounts of biomass are being used to make cellulosic ethanol, they should check out some of Robert Rapier's posts.

Um, since nitrogen is supplied, ultimately, by the atmosphere, it is the least of our worries... Well, right after CO2. For the problem nutrients, search the title of Gail's post.

But I'll humour you. Dry firewood has little nitrogen, about 0.09%. Straw has significant amounts of nitrogen, about 0.4% for wheat straw, 0.7% oat straw, and 0.9% for barley. There's enough nitrogen in barley straw that my mature sheep do pretty well on it for much of the winter. It will compost nicely if it gets moist and is given a chance to breath.

The carbon neutral fuel I use is wood. (Of course, the non-neutral carbon fuel that I'm absolutely dependent on at the moment is natural gas. The house we are building will be actively heated by wood burnt in a masonry wood-stove and passively heated by active and passive solar.) To supply this fuel, we have about 10 acres of poplar at the moment, but have fenced around it so that it can expand. (Around here, it expands out at about 12 feet per year and starts being worth harvesting in about 8 years.)

But my point was that returning ashes to the soil in no way closes the nutrient loop as you have lost phosphorous. Unfortunately, phosphorous isn't easy to replace.

But my point was that returning ashes to the soil in no way closes the nutrient loop as you have lost phosphorous.

What happens to the phosphorous?

That is a really excellent question. I suspect, but haven't been able to verify yet, that there wasn't much phosphorus there to begin with. Here's the best I've found so far.

"The effect of whole-tree harvest on phosphorus cycling in a northern hardwood forest", Ruth D. Yanai, Forest Ecology and Management, Volume 104, Issues 1-3, 12 May 1998, Pages 281-295.

"The amount of a nutrient removed during a forest harvest depends not only on the combined biomass of tree parts removed but also on the distribution of the nutrient among the various tree parts. At the HBEF, as elsewhere, concentrations of most nutrient elements are lowest in heartwood and sapwood, intermediate in bark and branches, and highest in leaves and twigs (Likens and Bormann, 1970). Most of the mass of the trees in the 70 yr-old forest was in stemwood; the mass of leaves is relatively small (Table 3). Branches are the greatest reservoir of P in the aboveground biomass of this forest, comprising 56% of the total. Leaves plus twigs, because of their small mass, and stemwood with bark, because of its low P concentration, make up only 13 and 31% of aboveground P, respectively."

The study goes on to point out that removal of whole trees (all 10cm or greater diameter trees at breast height were removed) removed 50kg/hectare P, removing stems (trunk) only removed 6kg/hectare. That was largely because there's little P in the main trunk. (Presumably P is concentrated in growing tissue.)

However, firewood is mostly from the trunk. The smaller the branch, the less worthwhile it is to use it for firewood.

From the study:
"When compared to ecosystem stores of P in all forms, organic and mineral, the loss by all mechanisms of P in whole-tree harvest was slight. The amount of P exported in streamwater and particulate matter was negligible (Table 5 and Table 6). The amount of P removed in whole-tree harvest, although much higher (50 kg P/ha, Table 4), was still only 3% of total ecosystem P stores (1700 kg P/ha; Yanai, 1992). Calculations of nutrient losses from six sites in the eastern United States, including this site, showed removals of P, K, and Mg by whole-tree harvest to be ≤3% of total ecosystem stores (Federer, C.A., Hornbeck, J.W., Tritton, L.M., Martin, C.W., Pierce, R.S. and Smith, C.T., 1989. Long-term depletion of calcium and other nutrients in Eastern US Forests. Environ. Manage. 13, pp. 593–601)."


"Thus the whole-tree harvest removed 32% of the most readily available P stock. When viewed in this light, the fact that whole-tree harvest removed five times as much P as the adjacent stem-only strip cut suggests that the intensity of logging removal may affect the rates or pathways of P supply to the regenerating forest. To restore living biomass to its pre-harvest state would require a P supply equivalent to 58% of the P remaining in the forest floor and in stumps and roots in the case of whole-tree harvest but only 4% in the case of stem-only harvest."

What I haven't yet been able to find is how much P is in dry firewood and in ashes. My suspicion now is that not much P is lost in burning. It just wasn't in the firewood to begin with, since most of the firewood comes from the low-phosphorus trunk. Perhaps MarkinCalgary or someone else who claims phosphorus is lost can find a reference for that.

Um, since nitrogen is supplied, ultimately, by the atmosphere, it is the least of our worries...

The nitrogen in the atmosphere (N2) is unavailable to plants. It needs to be "fixed" into a nitrate before it becomes bioavailable. It is energy-intensive to break the strong double-bond of molecular nitrogen. This is done industrially using natural gas (Haber-Bosch process), which is obviously non-sustainable.

So if we don't take care of natural nitrogen fixers (primarily, legumes), then we'll be in a hurt when natgas runs out.

Come join us in nitrogen farming!

Wow, never heard of feeding straw to anything. I'd say you win the argument on barley straw and lose on the wood and other straws. If it's not at least 10:1 C:N then you need nitrogen to break it down, which was my point.

So let me get this straight:
"Ignoring trace elements, burning biomass drives off all the organic matter, all the nitrogen, most of the phosphorous, and some of the potassium. From a nutrient stand-point, the ash is only a pale shadow of the biomass you started with. Ash should be returned to the soil, but lets not mistakenly believe that doing so closes the nutrient loop."


"The carbon neutral fuel I use is wood."

So you think that burning wood for carbon neutral fuel is acceptable enough to do, but you think it's a bad idea because you lose some phosphorus in the process. And I wrote "If you reapply the ashes to the field, they contain the potash and some of the phosphorus in the original plant", but that was wrong somehow. And you're doing basically the same heating scheme as I am (though it sounds like you're using more natural gas), but I'm doing things wrong? Why do I feel like I'm arguing with an alternate universe version of myself?

One thing that gets left out in the discussion about minerals in the soil is creatures in the soil.
These include:


Bacteria from all four groups perform important services related to water dynamics, nutrient cycling, and disease suppression. Some bacteria affect water movement by producing substances that help bind soil particles into small aggregates (those with diameters of 1/10,000-1/100 of an inch or 2-200µm). Stable aggregates improve water infiltration and the soil’s water-holding ability. In a diverse bacterial community, many organisms will compete with disease-causing organisms in roots and on aboveground surfaces of plants.

Worms which break organic material down and aerate and loosen soil among other things

Sugar-Water/Mineral exchange

This mutualistic association provides the fungus with relatively constant and direct access to carbohydrates, such as glucose and sucrose supplied by the plant.[4] The carbohydrates are translocated from their source (usually leaves) to root tissue and on to fungal partners. In return, the plant gains the benefits of the mycelium's higher absorbtive capacity for water and mineral nutrients (due to comparatively large surface area of mycelium:root ratio), thus improving the plant's mineral absorption capabilities.[5]

Plant roots alone may be incapable of taking up phosphate ions that are demineralized, for example, in soils with a basic pH. The mycelium of the mycorrhizal fungus can, however, access these phosphorus sources, and make them available to the plants they colonize.[6]

That's for starters and I am sure there is much we still don't know about the living soil. However without organic material returned to the soil life gets hard for these beneficials. I say living soil because one way of looking at soil is not all the component parts separately but the soil itself as if it was an organism. While that might not agree with the definition of an organism I think it is useful. It is a living medium (full of living things) that makes possible the life of other plants, that feed us. A healthy soil full of life is beautiful to feel and smell.

I mostly use my own variation of Ruth Stout's no till garden by keeping it under a continually replenished mulch and disturbing the soil as little as possible (tilling throws aerobic bacteria under and anaerobic bacteria on top which is not good for either and therefore upsets the soil balance, tilling also chops up earthworms). Having started with soil that is mostly clay in spots I have worked in some composted manure, but hope to soon just put compost under leaves and put the seeds in without doing any digging.

BTW Darwin wrote a book on earthworms available at or

Certainly what earthworms do isn't simple in ecological terms. The great naturalist Charles Darwin, after making a careful study of them, wrote this:

" may be doubted if there are any other animals which have played such an important part in the history of the world as these lowly organized creatures."

Good post, these are solid points.

I am burning deadfall wood on my property in a catalytic converter equipped outdoor furnace, and returning the ashes to my orchard.

That's funny, all of our ashes either go on our fields or in our compost bins. We're burning biomass for heat at this point, however. The power will come later. Do you know what people do with the ashes, or are you surmising this? I was under the impression that most people burning for heat are spreading the ashes somewhere, but that's from my limited knowledge of the other people I know who burn wood for heat. I also know that in the past, everyone who didn't live in a city either spread their ashes or used them for making soap.

And people seem to be forgetting that heating/power/CHP with biomass is a renewable form of energy that doesn't contribute to climate change. Certainly in places with good solar, wind, hydro, geothermal, etc. potential, it makes more sense to use those other renewable sources. We don't happen to have good opportunities for those other power sources here, however, and wood is plentiful and grows quickly.

As for improving the organic structure of the soil, yes, crop residues are vital, but again, you have to have a good source of nitrogen or your residues will leach nitrogen from the soil while breaking down. Same for composting. That's why you don't want to put woody residue on fields or in compost bins; there's far too much carbon.

I throw charcoal leftovers from my woodburner in the compost but not the ashes as i dont want the soil becoming to sweet. I throw the ashes on nearby land where nettles grow thick and fast each year. I then pulls these up and throw them in the compost.

We sift the charcoal out of our wood heating ash. The charcoal is then added to compost (terra pretta) and the fine ash is carefully, thinly distributed to keep from making the soil too basic.

Come join us in making terra pretta!

you have to have a good source of nitrogen or your residues will leach nitrogen from the soil while breaking down.

Every human produces nitrogen every day and in most cases it gets flushed down the toilet. Diluted urine is a fine source of nitrogen. I cover my garden with leaves. I never have a problem with my plants not getting enough nitrogen.

We have a contract to sell 50 tons per day of wood chips for the production of electrical power. Tonnage is supplied by fast growing nitrogen fixing trees. The contract requires that the ash is returned to us and we do in fact spread it in the field. In my opinion, not doing so is incredibly stupid.
As to what is lost in the burning process, the temperature of that process is the key. If the process is high temperature burning then certainly some of the nutrient value will go up in smoke, so to speak. However most gasification processes and certainly pyrolysis processes leave most, if not all, of the minerals in the resultant ash or char. If it is char, then the nutrients will not be as liable to wash away due to rainfall as the biochar surface area holds on to those nutrients, as well as water, quite tightly. Fortunately plant nutrients can be grabbed back by rootlets of the plant. Cycle complete.

kjmclark, if it's a problem that deer have developed a taste for your black locust then perhaps you should develop a taste for venison

You know it! I'm trying to get my relatives to slowly develop a taste for venison as well. This year I plan to "harvest" two of my tree eaters. This past year I figured out the best place to get close enough to actually kill the first. We skinned and butchered it ourselves.

In that vein (wow, that's a really bad pun), I plan to reduce our groundhog garden destruction force this year as well.

And BTW, another source of nutrients for the fields is the parts of this harvest that we don't eat. Everything we don't eat goes in the compost bins, buried under a good amount of horse manure. Bone meal is a great source of phosphorus, though I expect it will take a long time for bone to break down in the compost.

I have trained some of the neighbors to come with their carcasses and "gut piles" and put them in my kitchen garden compost pile.
So do drop those rodents in the field and in the compost pile! Admittedly my neighbors use some gas on the atv's, but we usually swap stories, and sometimes vegetables and meat, and scaveneged materials at the same time. Lots of "peak" missionary work goes on.

I made the decision to keep all organics other than human waste on our property. Our lot has a large number of mature pine trees and an acre of farmland. We rake the pine needles from the areas around the house and spread them as pine straw over the farmland; it makes a annual layer about 4-6 inches deep; this requires an 8 hour day for two workers. I have planted red clover and hairy vetch on the farmland as nitrogen fixers; the pine needles let rain percolate through and keep the birds from eating the seeds. All other leaves are put in wire bins and used to mix with kitchen waste for compost for the vegetable gardens and fruit trees near the house. I have started separate bins far from the house for dog waste composting; this will be used after it is well rotted to supply some nitrogen back to the pine trees on the periphery of the property. All water is channeled to a pond we dug a couple of years ago. This can be dredged as needed and the mud can be spread on the fields so no nutrients are lost from the property.

You needn't be so worried about the dog waste...or human waste for that matter. Just this morning, my wife and I gathered up our dog's waste that accumulated over the winter (in, under, and on snow). The gatherings went right into the compost bin. A properly functioning compost bin, especially one of sufficient size (on the order of a cubic yard), will make short work of dog waste. Just dig an 8" hole near the middle of the pile (ie. where the biological activity is most active), put it in, and cover. You won't smell a thing. Honest.

Composting human waste is very similar. The only trick is in gathering the waste to begin with and, again, to have an appropriately sized pile. Joseph Jenkins goes into great depth on the subject. As someone with some experience in this area, I can say it isn't as bad as one might think. If things got dire, I wouldn't hesitate to go this route. The only reason I don't plan on using our Jenkins-style humanure composting system is that we are having a composting toilet installed. Rather than compost our waste in a far corner of the property, we'll be doing it right in the house.

You may already know this, but I would be careful spreading pine needles. Conifers will tend to acidify soils, which may not be conducive to what you're growing. That's why you rarely see earthworms in the soil underneath conifers. If you're on a limestone soil though, probably not an issue.

Re. pine needles and acidity, in our area we have to add sulfur because the pH is so high. If only pine needles were enough to lower it, I'd be delighted. It's somewhat controversial whether pine needles change the pH at all; I have never been able to grow acid-loving plants in spite of having plenty. Pine straw is becoming the mulch of choice over much of the south, and doesn't seem to be harming plantings at this point.

Earlier today I drove past some high yield farms with low input yet which make a profit. The crops were hops (for beer flavouring) and black cherries. The key elements seemed to be
- overhead 'fertigation' whereby fixed sprinklers deliver water and dissolved nutrients
- small machines such as 30kw/40hp tractors because there is little digging and easy harvesting.

Cheap water and deep alluvial soil no doubt help. Many of the places that enjoy those benefits are now paved over as suburbs and will have to be converted back to farms. Water could come from dewatered sewage albeit at some energy cost. Nutrients in liquid form could come from compost tea or worm pee and solids could be added to the soil each year. Sources of those solids could be humanure, ash from gasification processes and sewage sludge. While the liquids and solids will contain NPK they will also contain dissolved metals, hormones and pathogenic microbes. Crops harvested since the last rain will need washing.

Thus vegies could be grown in furrows created and mechanically weeded by low powered machines. Overhead sprinklers could deliver water and organic nutrients. Skilled growers could detect the need for crop rotation and minor supplementation eg with superphosphate. A higher proportion of our diet will come from root crops and we will eat less meat and dairy. Example instead of a steak we'll eat burgers made from potato, onion, carrot, beans and just a few grams of meat or cheese. Suburban farming will become a major employer; the workers won't get paid much but they won't starve.

That reference is great for NFT. Didn't know about the red alder opportunity, I will have to add them to the land now.

For potassium I've been growing Russian Comfrey who's deep roots extract it I bought an
old book printed in England on the cultivation of Russian Comfrey. I use type 14 which does not seed, and can only be propogated
through root division. To date I am only using it for my "kitchen garden", which is all raised bed with some experiments like
"bucket peas & beans"

I am covering about three of my 60 acres with free range chickens (60 going to 200) through mobile coops and temporary electrical
fencing, I can't imagine raising that much comfrey. While we have considered rabbit tractors to bring this up to scale, we consider
the hens too valuable at the end of the day to be in the nooks and crannies of our rolling land. We love the brown eggs of the Rhode Island
Reds and New Hampshires.

So, I am building my first rabbit tractor, their fecundity and growth is so fast compared to the chickens that we feel that we can risk
them "out there". Their ability to eat pruned apple and other fruit tree limbs also enters into this consideration as our orchard continues
to grow. we're hoping that the rabbit droppings through the tractors will scale up to a 5-10 acre per year solution with no "feed" for 8 months.
This would require extensive "harvesting" of rabbit meat in the Fall.

Alder is also good for coppice. It's not just red alder, which has a pretty limited range; black (european) alder fixes nitrogen as well, and it's naturalized most of the northeastern US.

The Bocking 14 comfrey is the recommended comfrey for one form of humanure processing. That's the one we use too at the barn.

PA's DCNR considers black alder an exotic invasive species.

Good thing I don't live in PA. Some states consider black locust to be invasive as well, though it's native to the US. It's funny how many of the nitrogen fixing plants are considered invasive. Vetch, kudzu, scotch broom, mesquite, black locust, alder, white clover, sweet clover - there are probably many more I don't know about. There must be something about fixing nitrogen that makes those plants unruly.

this is a monoculture ag state. pour on the inorganic fertilizers, use hybrid seeds, now GMO seeds with notill and lots of roundup

everything will be fine for the next 3 days, life is good.

Being an EE/CS/MDiv background I remember the day when I found out that all the fertilizer for the miracle of agriculture was based on
NG, I had a panic attack, I couldn't believe it. What do you mean, no feedback loop, open systems are inherently unstable!

My dad, my great uncle, and the Amish had camoflaged all that for me.

We live in Alabama and have a number of autumn olive trees which are nitrogen fixing - it is an import from china and considered invasive. I don't find it excessively so. I am always glad when I find a new one popping up. The berries are a bit astringent but make a jam that tastes like cranberry sauce. Most of our chickens think they are just fine. And I am starting to harvest them for fire wood. They don't grow straight but I cut most of our wood with a hand saw so that doesn't really bother me. I just take out the largest oldest branch and let the plant keep growing. Many also make nice perches for our chickens where they grow out rather than up.

I thought I would address a major misconception here.

The term "nitrogen fixer" is a subjective label that describes the ability of a plant to grow in the absence of organic nitrogen in the soil.

The fact is nearly ALL green plants are "nitrogen fixers".

Second, it is not a property of the plant but the property of the bacteria in the soil that the plant has a symbiotic relationship with.

Legumes and other "fixers" you mentioned will not necessarily work to fix inorganic nitrogen. Lets say you have some N in the ground, and you plant legumes. For as long as that N is there, those beans are using it (instead of working with the bacteria). The Alders are referred to as "nitrogen fixing" only because they take advantage of the bacterial relationship to a relatively greater degree than any other green plant around. And how? possibly because they do grow tall and rapidly, and are skilled in finding the sun perhaps better than other plants. This gives them more roots and more bargaining power by providing the starches the bacteria like to eat. The weeds that you mention propigate in areas without any oversight beyond the initial land rape. You're right, they are selected for because they do well in poorly managed land (which I consider most farm and civic land to the degree they have less general biodiversity than a complex, "wild" area.) Disturbed land is disturbed land.

Other plants (annuals for instance) aren't considered "fixers" because there is a net loss of N because they are removed from the ground. Not to mention the fact that the roots rot underground (which removes N), or is probably tilled/compacted (which removes capacity to convert N).

So if you want "nitrogen fixation" to cycle in your field/garden/whatever, you need to let things grow so they have that bargaining power. You need to have good tilth, air, water, bacteria, fungi, and worms. And all of these things need "settling time". Adding too much manure/N just means the chemical breakdown "burns" the balance.

The best source of nitrogen is properly mixed and cured compost or worm castings.

You'll have to take up that argument with botanists or chemists. The term "nitrogen fixing" is usually defined the way the Wikipedia defines it:

Nitrogen fixation generally refers to the natural process, either biological or abiotic, by which nitrogen (N2) in the atmosphere is converted into ammonia.

What you're describing sounds to me like a combination of nitrogen fixing and nitrogen scavenging.


sorry red alder does not coppice. Best choice is scouler willow.

Richrd, you'll have to take that up with the US Forest Service:

Vegetative Reproduction- Red alder sprouts vigorously from the stump when young. It can be repeatedly coppiced on short cycles but rootstock mortality increases with each harvest (17). Age, time of year, and cutting height influence the likelihood of obtaining stump sprouts and the vigor of the sprouts (15). Stumps will sprout best when trees are cut in the winter and when stump height exceeds 4 in (10 cm). Older trees rarely sprout and coppice regeneration cannot be expected after polesize or saw-log-size material is harvested (15).

I personally only know about black alder.

Any BBQ ash plus charcoal is distributed in the yard. Also chipped tree/brush/grass debris. The ash is a source of potassium and some phosphorous, perhaps nitrates as well (gee, we could Google ash composition to check). The charcoal bits help to hold some nutrients in the soil, ala the Maya slash & burn jungle methods. The soil microbes are so active in Hawaii that much of this plant debris is consumed in only a few months. Also, a cut on the foot area is very serious because of a subset of these microbes. I've had friends here who have nearly lost legs from gangrene because of a simple ground scrape that wasn't tended to properly. Wood in/on the ground is also termite bait.

As Dr. Frankenstein once said, holding a handful of dirt: "It's alive!"

I am wondering how long our wood frame houses will hold up, in termite country (like Atlanta, where I live)!

If you aren't afraid of the chemicals necessary and they haven't yet been outlawed, just about forever as far as termites are concerned-but this is a problem that absolutely requires attention-beginning with inspection at regular intervals.

There are ways to modify houses, particularly the foundations and crawl spaces, that offer a lot of protection, but this is only practical during the initial construction most of the time.

I hear that some of the termites that have gotten into this country recently can live w/o a source of moisture such as a tunnel to the earth, which is usually damp.This may or may not be true; if it is, we are in a whole new termite ball game.

I understand one set of chemicals was outlawed in the US. Now they are using a chemical used in flea treatments for dogs and cats.

This is something I haven't been able to find information on.

Our property was treated for termites more than 20 years ago (the soil around the foundation), and has been inspected twice in the 7 years we have owned it. I have grown nothing edible in the backyard on the basis that there could be pesticide residue.

We have two dead trees at the back of our property, one is common to three properties, the other to two. There is a termite population here, and the exterminator has recommended that we remove and stump the trees and treat the soil to "weaken the colony."

Would the pesticide have dissipated after 20 years? Will the new pesticides make the soil unsafe? Is there a safe distance from injection sites for growing food?

Anyone out there know?

Use a biological weapon.
Metarhizium anisopliae
or bassiana

(Paul Stamets, Mycellium Running, "How Mushrooms can help save the World". pp114-123 isbn978-1-580-08579-3)

Not only will ash be low in nitrogen and phosphates (both acid forming elements tend to burn, leaving pH lowering elements such as calcium and potassium, which is why ash will lower your pH), but any charcoal will have the effect of absorbing nitrogen such that plants can't use it. As the charcoal decays, the nitrogen will eventually be released, but straight charcoal will effectivel suck the nitrogen away from plants.

I grow Bocking 14 Russian Comfrey as a green manure - wish I could keep small livestock, but unless I want to raise rabbits that's not an option in my subdivision.

Permaculture expert Peter Bane explains that human urine is a good source of both nitrogen and phosphorus. It must be diluted for use as a fertilizer, and one must be careful to avoid a build up of salt in the soil. (Lay off the nachos?) There's a book on the subject (haven't read it): . There are also many links to information on the subject, such as this one: Go a-Googling to learn more. At any rate, in a pinch, fertilizer is not as hard to come by as we might think.

InKyDo, I've read the book, and it's pretty good. Yes, urine is an excellent source of phosphorus (0.7-1.6 grams per adult per day) and potassium (1.5-2.0 grams per adult per day) as well as nitrogen. One key for using it as a fertilizer is to add plenty of carbon -- the bacteria that break down the nitrates into plant-accessible forms need a carbon to nitrogen ration of 8 to 1. Sawdust, dry leaves, and other low-nitrogen organic matter works well.

Thanks - I didn't know about adding the carbon at an 8:1 ratio. Liquid Gold is one of those books sitting in my Amazon cart, saved for later. Another is Paul Polak's "Out of Poverty." Polak notes that, in the form of fresh urine, an average adult produces "the equivalent of twelve hundred pounds of totally soluble 12-4-4 fertilizer a year."

Given our high sodium diets, isn't there a problem with salt build up in the soils if urine were used in very high quantities?

Here's my personal tale of salt damage, which appeared last Spring.

More or less, I collected a large pile of tree leaves in the fall and emptied buckets of urine on in it all Winter, for like five months. In the Spring, the pile was turned a few times and tilled in as leaf mold, or applied as mulch in a clay garden soil of about 1500 square feet of elevated ground. In two previous years the soil had also received some urine.

All of the Spring crops were stunted, the English peas in particular grew as tiny plants.
Summer crops however, produced well following a wet spring, so the effect was short lived.

I attribute the uniform acute effect to the quick release of salt from the leaf mold during Spring rains, exacerbated by the high sodium content already accumulated in the clay.

Interesting. Do others have similar stories?

Dohboi, that depends on your local rainfall and water table. If you're in a dryland area where evaporation is where much of the water ends up, yes, that can be a serious issue. A lot of people dilute urine before putting it on soil; of course you can also just mix the urine into humanure and compost it, or stir the urine-and-carbon stuff into a freshly made compost pile and let it go through the composting cycle, so any salt will be well diluted in the finished compost.

Thanks. I do, however like the idea that people will eventually move to lower sodium diets, not only because it is better for their body, but because it is better for the soil that the effluent from their bodies will ultimately reach.

I think if we had a stronger ethic in this direction, people would be more hesitant about putting all sorts of things into their bodies. Our bodies ARE the earth and the earth is our bodies. We need to start treating both with more care.

For the past century or so, ever since we ran out of South American bird guano, the energy to manufacture N-P-K fertilizer has come from natural gas, with the P & K mostly mined. On one hand, the cornucopia of unconventional gas discoveries will keep the wolf from the door with regards to providing the energy and catalyst for fixing N-P-K into usable fertilizer.

What that leaves us with is the issue of actually sourcing the P & K feedstock, as global supplies. From earlier readings on this site, global supplies of these two key elements have either peaked or look set to do so.

I doubt that better recycling of human waste, biomass, etc. can keep up with population growth and per capita meat consumption in the developing world (every extra kg of meat consumed requires about 10kg more of grain & oil seeds).

For those of you who think that we can all just be vegetarians, the amino acid and essential fatty acid deficits inherent in such a diet are just as problematic as eating junk food --and I speak from 8 years experience as a vegetarian (1994-2002).

What makes the impending N-P-K shortage all the more frightening is that essentially, top soil has been 'mined' of its nutrients. This means that in the absence of fertilizer, not only would crop yields drop, they would fall below pre-19th century levels, when the world was capable of feeding no more than 2 billion people.

Anyway, all that is food for thought. If we are talking about long-term, eco-friendly sustainability, a population reduction of at least 80% is the only real long-term answer.

"For those of you who think that we can all just be vegetarians, the amino acid and essential fatty acid deficits inherent in such a diet are just as problematic as eating junk food"

I hope you're joking.

As anyone who has paying the least amount of attention to the issue in the last fifty years should know, eating a variety of grains and legumes takes care of the amino acid issue. And many seeds and seed oils (sesame, pumpkin, flax...) have high quantities of EFA's, as do leafy greens, brazil nuts, avocados...

I'm sorry to hear you had a bad experience as a vegetarian. Next time try doing two minutes of research first.

And anyway, increasing sustainability does not require everyone to become pure vegetarians. Just cutting meat consumption back to what it used to be (and still is in much of the world)--a luxury, not a staple--would cut down greatly on waste we can't afford.

Having said that, I am essentially in agreement with your larger point. We are in for a very tough go of it, at lease, and that's even before factoring in the almost entirely harmful effects of GW on world agriculture.

Two strikes on tropicalcactus

For the past century or so, ever since we ran out of South American bird guano, the energy to manufacture N-P-K fertilizer has come from natural gas

The "past century" is a big overstatement, which would mean that we ran out of surface deposits in 1910. Why make such a statement when you can simply say that it has been declining rapidly recently. You can still make your point and not have to use dubious facts.

You speak as a first worlder with first worlder experience. Finding the correct blend for an exclusive vegetarian inputs in most countries in say Africa is very difficult, finding them at a cost that is affordable (life sustaining) to the bottom 1/3 of the populations
is impossible. There is plenty of really ugly experiences in Africa with an exclusive vegetarian input.

I actually was a vegetarian during college, I could not imagine an ability to construct in a post peak world in my town the
necessary inputs without a 30 year head start for an exclusive vegetarian diet. Sustainability is more realistic with chicken
and rabbit inputs, and a little farther south with tilapia. (though i have raised tilapia in a greenhouse using a solar pool heater
inside the greenhouse to concentrate the heat in the tanks).

Finally, the last time I looked the California nut business was being sustained by the use of 50% of all hives in the US this includes the hives from the East Coast. In my estimation the sustainability of nuts as a vegetarian input is ZERO unless you have them in
your yard (i have about 30 so I could go back to vegetarianism I guess), the energy to trailer those hives to california will not be there, and the energy to bring them from the far corners of the earth will not be there.

Flax grows readily in many environments, as do green leafy vegetables.

Again, I was not saying that vegetarianism is the perfects solution to all. Only that the particular problems raised about it were not necessarily huge problems for most of the people who would be reading these forums.

I dont think we should ignore synthesized N fertilizer either. The Haber process is energy intensive, about 10 times the energy invested compared to the mining of P and K.

And the creation of all the excess fixed nitrogen has been enormously damaging to ecosystems--huge and growing dead zones in the Gulf of Mexico and elsewhere...

The stat I've heard is that we now create artificial the same amount of fixed nitrogen that all natural sources produce. This over production has recently been rated as one of the top ten environmental threats in the world.

'6. Are there approaches I have missed?'

Start from a soil test. Then develop your strategy. Our soils have excessive potassium and calcium, due to nature of parent material. Organic matter content as percent of potential in your soil type is your report card.


Are there and farmers reading this list, ie know people who are working 60, 100, 400 acres of land. Questions and Responses should be different. For example, weigh decision to purchase and haul in manure versus cover cropping versus metered fertilizer use. As cost of fertilizer increases efficiency of use becomes more important. This is what is happening now why not report.

'India' and biological fertilizers

I have India envy, not only phosphobacteria but also selections and blends of microbes tailored to specific crops, regions. Seems to be result of directed government research, private public networks and public service. I have attempted to import these materials but alas not possible to import soil microbes.

The thing I worry about is the breakdown of our system of doing things--more or less because of losing international trade, or electricity, or both. To me, all this could happen as a result of all of the world's debt problems, so may not be as far off as many assume.

It would be very good to have all these things worked out before the lights go out, because it will be too late afterword. Even if it turns out to be 20 years away, research takes a long time, and scaling it up adds more time.

Some of the things we need to know are what kinds of supplements are needed where--what kinds of phosphobacteria are helpful--what crops work best without targeted fertilizer amounts/types and without spraying for insects?

Some of the things we need to know are what kinds of supplements are needed where--what kinds of phosphobacteria are helpful--what crops work best without targeted fertilizer amounts/types and without spraying for insects?

We know these things quite well already. We have become quite advanced in areas of science that encompass these fields. We have advanced degrees available from universities in Soil Science, Agronomy, Biology, Ecology, Microbiology etc... etc... Now getting this knowledge to the people who will need it the most, trying to survive in a post PO world by farming the vast dead zones created by industrial agriculture, well, that's a whole n'uther can of nematodes. Good luck with that.

But I don't think we know what to do this without our complex system supporting it.

I expect that quite a few crops would not be feasible in their current locations, if we did not have all of our current mechanization, irrigation, herbicides and insecticides, and soil supplements.

If we are relocalized, we will need to know how to grow a suitable mix of crops in each local area, with minimal inputs. I think we are quite far away on that.

But I don't think we know what to do this without our complex system supporting it.

My uncle has a small farm in the interior of Sao Paulo state in Brazil and two of my cousins are Agronomists. I also have a good Brazilian friend who is a soil scientist and has done a lot of work with detoxifying and bringing dead soils back to life and fertility. So I think that I can say with some confidence that we do have this knowledge. Unfortunately transitioning from the industrial systems of food production which we have adopted is probably not going to be smooth or painless.

I expect that quite a few crops would not be feasible in their current locations, if we did not have all of our current mechanization, irrigation, herbicides and insecticides, and soil supplements.

I'd agree 100% with that statement!

If we are relocalized, we will need to know how to grow a suitable mix of crops in each local area, with minimal inputs. I think we are quite far away on that.

Again, I'm quite confident that we do have this knowledge already and slowly but surely we will see more and more of it being applied out of simple necessity and the fact that mechanized fossil fuel dependent farming methods won't continue if fossil fuel is not readily available. To be clear I'm referring to all the inputs such as fertilizers, herbicides, pesticides etc...when I say fossil fuel dependent.

Perhaps Jason Bradford would chime in here with his expertise and practical experience.

I think we know what should be done in theory and a lot of practical know-how is available too. The trouble is the scale and pace of the transition required. Will this be a slow adjustment based on less costly and more efficient methods overtaking the current system, or will current ag practices fail spectacularly over a short period of time?

I can see how a slow transition could be managed.

1. Start by reducing the acreage in annual seed crops for animal feed and put pasture back. This will help a great deal in keeping soluble nutrients from running out of rivers and creating the thousands of gulf dead zones (not just the big one in the Gulf of Mexico).

2. Make sure the pasture is a diverse mix, including legumes, and managed to be as nutrient self-sustaining as possible. The microbial life will return as fungal hyphae recolonize the roots of perennial plants and manure from grazing lifestock innoculate the topsoil. If needed, bring in compost teas and related biological inputs to jump start this process. Compost teas can use finished compost and forest soil duff as the innoculant. Remnant natural ecosystems are the repository of the biodiversity needed to bring life back to ag soils. Most of the minerals exist in large enough pools in prime ag soils that they will become available to plants once the biology is working right again. This may take a few to several years.

3. When doing annual seed crops (e.g., grains, legumes and oil seeds) work towards reduced and conservation tillage methods and always rotate with green manures for nitrogen balance. Don't export the straw. Periodically rotate animals back onto annual cropping land by fallowing in short-lived pastures for a year (e.g., with species such as annual rye, red clover and forage brassicas).

4. Use edges and marginal growing areas for beneficial uses, such as hedgerows and nitrogen fixing trees. Restore riparian corridors and allow for more natural flood regimes to occur.

5. Over the long-term, transition to more perennial seed crops. These are under development and could use more support. Researchers are looking to perennialize relatives of major small grains, corn, sunflower and some legumes.

6. Over the long-term, sort out how to bring humanure back to the land. While 1-4 buy us time, 5 & 6 are required eventually.

"5. Over the long-term, transition to more perennial seed crops. These are under development and could use more support. Researchers are looking to perennialize relatives of major small grains, corn, sunflower and some legumes."

OK, but then how do you deal with perennial weeds?

find a use for them,

compost them,

plant a more desirable plant in the area that crowds them out,


Mash, let me rephrase the question. How do you deal with perennial weeds in perennial crops? The big crop scientists are working toward is perennial wheat. If you happen to get canada thistle in your field of perennial wheat, how do you get rid of the thistle? The usual way is to sweep the field repeatedly, dump herbicides repeatedly, mow repeatedly, or plant a smothering cover crop *and* mow repeatedly. All of those will prevent your perennial wheat from fruiting.

I'm betting that you'd have to treat your perennial wheat like alfalfa and just expect it to be bi- or triennial and plan to deal with the weed buildup later. But your yields would decline each year as the weeds increased. And how would you deal with hessian fly in a perennial wheat crop?

I would think that Jason will have thought of problems like these, so I'm just curious what his answer is. It's kind of nice having annual small grains; they help create good rotations. If we make them perennial, we gain some things, but we also lose the benefits of rotations, like weed and insect pest management, and the fertilizing effects of green manures in the rotation.

1. Switch from grain-fed to grass-based livestock (dairy and meat), rotating the grazing and haying fields.

2. Prohibit industrial dumping into sewage systems and recycle treated humanure. Or people employ the Humanure Handbook methods at home in their large garden.

Any thoughts by farmers? I realize rotating between grazing fields and hay fields means more fencing, and not all grazing fields are suitable for haying (outcroppings, slopes, blind ditches, etc), though this certainly reduces manure/urine collection and redistribution costs in energy and labor.

Your first idea definitely sounds good. Would be better for those eating the meat and dairy also.

Won't all the pharmaceutical products still be a problem with recycling human waste--perhaps the high salt content too? or is that only in liquids, not solids?

That would depend on which pharmaceutical and the conditions under which they break down. Part of the problem is the effluent from sewage systems that are used by pharmaceutical companies to dump byproducts, sludge, or batches that fail quality control.

While my greater concern has been with heavy metals, dangerous viruses, dioxins, PCBs, and pesticides from industrial effluent, the subject of pharmaceuticals has certainly attracted scientific attention, so merits further investigation. Good point.

Separately, the home practice of humanure should be safe, given that the residents should have an understanding of their prescription profiles.

I don't think people realize that one of the major mechanisms of energy transfer within the human body is ATP, adenosine triphosphate. It is also called the "molecular unit of currency"

and also that phosphate production within the United States is currently trending down, following a hubbert curve of it's own. Does anyone know if a hubbert linearization plot has been done for phosphate production?

Less phosphate means fewer people.

Hubbert linearizations have been done for phosphate and have appeared on this site. However, they do not agree with the USGS phosphate reserves, which shows more P.

K can be obtained from sea water as a byproduct of sea salt production in solar evaporating ponds, although I doubt this has good economics as long as high concentration KCl is available for solution mining.

Phosphate was more heavily applied years ago when it was relatively less expensive. Now the tendency is to do more soil testing. Also, there is a lot of fluctuation in fertilizer prices; when market tightness develops prices rise sharply until new supplies come on line. There is a worldwide excess of nitrogen capacity with the price of natural gas determining the price of N. Asia in particular overapplies N while it is used in more efficient amounts in the US.

I used to worry about the USA phosphorous supply, which is estimated to be about 25-30 years left at current extraction rates. Since we will have bigger problems with oil and energy way before we run out of phosphate, and we in theory could buy/steal it from foreign suppliers like Morocco-Sudan, it's not that close to any top worry at this point. Canada still has lots of potassium to mine and export. Nitrogen fixation seems covered by natural gas.

Less consumers in the future will take the pressure off many resources. Too bad we didn't see that coming and stop population growth and excessive consumption voluntarily.

I don't think people realize that one of the major mechanisms of energy transfer within the human body is ATP, adenosine triphosphate. It is also called the "molecular unit of currency"

Of course they do... ;-)

There isn't any way to prevent the loss of nutrients when farming the same plot of land year after year. I can do a pretty good job of keeping my garden's soil fertility up by composting all plant wastes and composting my own humanure. I also add animal manure from my cows mixed with straw bedding. This works fine as long as there is a functioning industrial agriculture system in place. When that becomes no longer possible the guy I buy hay from won't be able to produce hay without adding fertilizer to his fields. I would need to put the manure from the cows back onto the hay field. And the straw wouldn't be available either.

When fossil fuels, rock phosphate and potash become exhausted agriculture will be only possible in a few locations like flood plains that receive regular nutrient replenishment. Humans are going to have to revert back to nomadic herding, slash and burn agriculture, and hunting and gathering like we did for millions of years. Of course only a tiny remnant population will be able to survive this way. But I'm sure you already knew that.

For all of agricultural history up to the last 100 years or so, we didn't have or use fossil fuels and mostly got by on manure and crop rotations. For most of that time people didn't even know to rotate in a nitrogen-fixing crop. That was a late middle ages innovation.

Nitrogen, potassium, and phosphorus are pretty much everywhere, but the processes that fix and free those elements for plant use are much slower than haber-bosch and mining. We would probably have lower yields without chemical fertilizers, but it we wouldn't have to revert to nomadic herding and slash and burn agriculture, much less hunting/gathering. And there's nothing involved in mining that couldn't be done with electricity, natural gas, and human/animal labor. Mining was also done long before fossil fuels.

Not saying we aren't headed for problems, but I think we'll run low on energy and money for NPK long before we'll run out of viable sources of NPK.

Thanks for raising the topic, Gail. I'm sure we're going to be hearing more about it (even more so our children and grandchildren.)

From what I can see, the problem of nutrients for agriculture is not one that is "solved," for example, with a clever industrial process. Rather, it is an ongoing dilemma for humans, one that is met in many different ways: humanure, seaweed, fossil fuels, compost, bacteria, etc.

A simple way to get humanure is to put your urine in the compost pile. The concentrated N really heats up the composting process!
The only reason I stopped was that our compost was on shared property and I was uneasy about being seen pouring the suspicious looking liquid on the pile. Plus, you really can't leave urine in a container for too long. It does get rather rank.

I think Energy Bulletin published the first recent article on peak phosphorus:

Also see the background readings:

There's a group in Australia that's devoting itself to the issue:

Energy Bulletin

A whole mindset change is needed. Could we feed all the people on earth today by going back to something on the order of Forest gardening? Yes, and No. Yes if we had the time to set up the designs all over the world and stop how we are currnetly doing things. And No for that same reason, we don't have the time to set up the designs for everyone.

Plants do a good job of getting most of their own NPK, by living in whatever mixed system they lived in before we went about changing it by tilling and making fields full of a monoculture, which distroys the land's ability to sustain crops.

The only way we will be able to make a dent in the problem is to change how people get their food.

NPK is not the biggest elephant in the room, Water is!

The need to change where and how we grow food, will be the game changer most likely even before peak oil sets in really good and strong.

No easy answers. But one thing people can start doing is growing as much of their own foods as they can, finding out what plants can grow in their areas and what plants will help build their soils up from whereever they are now. Reduce the amounts of water they use now, thinking about how they do things water wise, and using water saving methods. harvest rainwater from their roofs for plant use is another method to look into.

Lots of little things that over time add up.

BioWebScape designs for a better fed future.

Gail and all,

1. Composting all garden and kitchen wastes, and gearing up for humanure.

2. On the backyard garden scale I'm working on, absolutely.

3. I've never had a problem with these -- my understanding is that a compost-centered organic approach tends to mitigate difficulties of this kind, since you're not dumping nutrients in highly concentrated bioactive forms.

4. No, I do my nitrogen fixing with legumes, including cover crops.

5. We recently bartered for a composting toilet, used but clean, and in need of a few spare parts. Now that the weather's better and punching a hole in the roof will be a good deal less of a mess, that's going in soon.

6. Urine. See my comment to InKyDo below.

"...and gearing up for humanure."

First step would be to get the population off pharmacuiticles.

Enigma, I don't use pharmaceuticals and neither does my spouse, so our humanure supply will be pretty safe where that's concerned. Of course you're right that drugs in humanure and urine can be a concern; still, as the industrial economy unravels and industrial medicine goes with it, that's likely to be the least of our worries.

Where to start? First, phosphorus is marginally water-soluble, moving only an inch or so per year into the soil. If phosphorus is leaving the field with runoff, that means it's leaving with a substantial amount of soil or manure. Save the soil, save the phosphorus. Water-solubles, such as nitrogen and potassium leave the farm or garden with just water runoff. That's a problem in wetter climates, 25+" of rain a year. Holding the water turns your ground into a swamp (even more problems), losing the water loses the nutrients. If you have enough land, you may be able to build a pond at the low end of your place, seal it with clay, and pump the water back in dry weather.

Dr. William Albright, University of Missouri, showed years ago by using radioactive phosphorus so he could measure it, that when it is bonded to organic molecules, i.e., is part of decaying plant matter, phosphorus is about 100 times more efficient in the next crop in moving nutrients from the roots to the leaves than mined, acid-treated phosphorus. In other words, one pound of P from last year's crop equals 100 pounds of purchased P. A very good reason to hold onto your crop residue and manure. Plants keep reusing the same P molecules to transport other minerals all season long. Also, if you are one to buy acid-treated P, know that almost all of the P gets bound up with calcium within 3 weeks of application, so apply it near the seeds when you plant. Once it's bound up with Ca, applied P won't be generally available for 20 years, when microbes get around to releasing it. That's why farmers are usually told to add some P every year. The exception is legumes; they can break apart the Ca:P bond making it available to the legume and to next year's crop that feeds on the rotting legume. On our farm, we can actually see the effect of one yellow sweet clover crop on the next ten crops.

It is my hope that mankind can retain enough science knowledge to be able to do soil samples and leaf analysis. All soils are out of balance in some way, some worse than others. My soil is extremely heavy in potassium, due to large deposits of volcanic ash, inhibiting even calcium uptake. Wood ash is a no-no, and some of my fields should not have manure, fresh or composted, on them. Do the soil tests and, as I've written before, I highly recommend Neal Kinsey (, because he is so thorough and sells no product other than his expertise. Actually, I dream of a national crash program, before we run out of oil, to remineralise and balance our nations soils so we can eat healthy for years to come. We have so wasted the oil on trivial things.

I know a man, retired now, who spent his life researching and developing microbes to aid agriculture. We tried some of his stuff and it works most of the time, although it often doesn't do well with chemical agriculture. It does help heal up over-chemicaled soils. His sons are carrying on the family business ( I have seen tremendous results using their Ocean Trace minerals as a foliar feed on garden crops. He told me some time ago that he had microbes that could pull phosphorus out of the air for their own use, thus adding it to the soil, and he's dealt with non-rhizobial, nitrogen-fixing bacteria for decades. It has been a long, hard struggle against the large ag corporations with their scientists-for-hire.

My cousin, a missionary in rainforest and open savannah Africa, used leguminous trees there, with good success. The rotation is: Year 1) plant trees (they grow 30 feet a year), Year 2) chop the trees back and plant corn, using the leaves for livestock feed or starter for an algae bloom in their tilapia fish ponds, and the wood for building or cooking. Cut back the regrowth during the corn season, Year 3) Let the trees grow up again. Rotate with other plots so there's always corn growing.

I'm not using humanure yet. I don't trust it, even from the nearby small town--too many small batteries get flushed, also too many meds and estrogen from birth control pills. Early settlers, of course, had the outhouse. When the pit was full, they'd move the outhouse to a new spot, fill in the old hole and plant a cherry tree. The trees did well and lived a long time in this harsh, high plains climate.

Long term, the earth goes to an acid bog unless volcanoes erupt and continents churn and ice ages grind rocks to powder. We are thinking beings. I see nothing wrong in redistributing minerals ourselves in a careful, knowledgeable manner, even if it's by mules should we have no trucks.

There is almost no way to pin down all the variables involved in a freewheeling forum discussion such as this one when you are talking soil fertility.

One person considers that he is operating sustainably if he expects to be able to garden and farm "his way" for the next few years or decades; others are talking in terms of historical time,centuries or milleniums;others are talking in terms of evolutionary time , or even geological time.

And time is only one of dozens of possible bones of contention, such as the definition of "organic".

Furthermore there are always those who know next to nothing but insist on muddying the water just to see thier comments in cyberspace.

It is not possible to talk meaningfully about soils on the grand scale in a few words, but I will do what I can.The first thing that must be understood is that soils are always changing over evolutionary and geological time due to plate tectonics at the largest scale , thru weathering and erosion of mountians on a lesser scale , thru being blown by wind and deposited by water, thru other scales right down to the bacterial and viral and molecular level from day to day and season to season.

Most of us here realize that "sustainable" is a word that is somewhat malleable, like chewing gum.As a professionally trained aggie, I can say with confidence that even bau agriculture is sustainable on most farms when the time scale is human generations,so long as the inputs are still available.Stretch the scale out to centuries, and bau agriculture is a recipe for disaster. We are getting close to a possible collapse of bau ag, as we have been at it for over a century now in terms of depending on imported materials, lots of manufactured machinery and chemicals, and above all energy from oil and coal and ng.

I don't have the time to go into a thorough discussion of why, but most of what the typical commenter here consider "sustainable" is probably only sustainable on the scale of human generations, just like bau industrial ag;the methods proposed depend on a set of assumptions that simply are not likely to hold up over historical time.There is no assurance for instance that manure from a horse farm nearby or bone meal or green sand from far away will always be available.Irrigation water may be diverted to other uses,and "sustainably" produced crops may lose out in the market place .

But as a practical matter we can try to talk about methods that will probably work over the only time scales that really matter-the next five or six decades.We can only do what can be done during our lifetimes.So let us talk in terms of the next fifty years or so.Given the current state of the world, ecologically and politically,trying to predict events and trends more than a few years into the future is a matter of almost complete guesswork anyway.

More tomorrow-it's getting late.

Funny you say that I've come to the conclusion that realistically you need the population low enough to migrate to allow whole regions to rest for hundreds of years.

Basically if a particular region is used by humans for say 100 years every 500 then no way do we have problems. Perhaps the math can be refined but you get my point.

In the end it seems that going back to a more migratory culture makes the most sense.

This is obviously assuming a much lower population number but the neat thing is if you do control population there really is no intrinsic reason you can become more migratory.

Certainly we probably want to keep some permanent cities but these could readily be supplied by boat assuming they where by good routes And of course parts of the world do have the natural replenishment similar to the the Nile. Your always going to have many places were flooding rivers make effectively permanent living possible.

Not a lot and I suspect closer to population levels last seen in the Stone Age however I'd argue that one thing people need consider is what population levels do we really need to be advanced. I'd argue if you took the state of California or England or France or Germany etc any one of these could be shown to be capable of all possible advances. And thats without optimizing for say research or the arts etc with most of the population toiling away at inane jobs.

A few hundred million people alive at any one time with a stable and advancing culture is more than enough to allow us to advance technically at a very healthy pace and focused also not creating a better mouse trap but real advance with longer term goals.

As I said sure some will live in basically permanent cities but the rest need not.

First you have to have the goal of population reduction but in my opinion if you take that route or probably more correct the decision will be made to go this route regardless of what we want then eventually I just don't see problems.

How fast we could get to what effectively a return to eden is and open question.
And that depends on what drives us to accept population control as a key part of our society. But also the people who solve this population problem won't be us and won't have our culture they will be I suspect very different.

Continued Ramble Part Two

A number of KNOWLEDGEABLE people who actually farm or garden in a very serious way have pointed out the inconsistencies of sustainability arguments over night.

They are mostly in the money, or dead on,and thier arguments may be summarized as "A farm is not an ecosystem".And even what we think of as a local ecosystem generally depends on the flow of some materials and nutrients into the area in question to replace those flowing out;even a stream in a pristine wilderness moves some soil, and animals living in such an area migrate and both import and export materials by doing so.

The bottom line is that nearly everything described as sustainable is only a move in the direction of true sustainability, which in terms of farming probably cannot even exist except as a concept.

All we are doing,all we can do, is delay the inevitable; but the good news is that it can be delayed for a pretty long time, maybe almost forever in terms of human scale perceptions.But the whole argument of sustainability boils down to robbing Peter to pay Paul.

So realizing the true scope of the issue, we do what we can, if we are smart, and in a position to do something; and all of us are at least able to advocate for positive change.

So on our place we mulch and recycle and we import organic materials as we can when it is economical to do so-we get spoiled hay sometimes, we get bagged leaves at the curb in the fall when we are going to town anyway, we grow cover crops and plow them in as soil builders or let them rot on the surface after mowing-it is not good to have a heavy ground cover in an orchard as it provides a fine habitat for rats and mice.

We make up the shortage the only way we can, and stay in business-we buy the necessary amounts of NPK, but we test and we use3 as little as we can and still turn a profit.Some goes into gardening simply because it sis cheaper to buy in terms of time and labor than it is to do without and scrounge enough leaves and manure, etc.

Manure and stable litter or poultry house litter is getting hard to come by, and sawdust is just as scarce.All these materials are being used by thier original owners, or sold, sometimes as is , more oftem after composting, drying, and bagging.

By careful management and judicious robbing of Peter on one's own property , it is possible to restore the fertility of a field over aperiod of time-but whatever leaves the premises absolutely must eventually be hauled back from elsewhere unless Mother Nature hauls it for you-as in the case of river deltas.

But anyone who thinks the materials necessary are going to be free over the long haul is niave at best.

Now as to human doo doo and urine, and dog and cat wastes-there are quite a few laws and regulations on the books in respect to such fertilizers, and failing to follow them can lead one into considerable difficulties with tptb.As a practical matter, I advise anyone using these materials to do so quietly indeed, if he expects to be selling any product for use as a human food.

It's one thing to blog about humanure; I assure anyone considering it that he better keep his trap shut about it if he expects to serve the produce of his garden to his prospective new inlaws or sell to the typical consumer who is willing and able to purchase premiom priced produce. Such consumers are all touchy feely about organics, but most of them think thier own doo doo comes out wrapped and sealed in cellophane , and like to think thier food is grown the under similarly sanitary conditions.Commercial operators who use sewage sludge are not usually faced with this delicate problem of course because they are selling to the masses thru middlemen.We pee in the fields as a matter of course around here , but even the scientifically educated women will have nothing to do with chamber pots , except as collectibles.

Biofuels may turn out to be one of the the final nails in the coffin of modern civilization as a result of environmental degradation even if we some how manage to get the population under control.As a matter of strategy for environmentally concerned people , I suggest that strategic efforts should be focused on killing the automobile culture and in general promoting a society along the lines of the one outlined here by Alan of the Big Easy.

Soils are an incredibly complicated substance, and the removal of the organic matter conventionally left as crop residues and allowed to rot is about as far from a sustainable practice as you can get over the term of decades and generations-it virtually gaurantees that the manufactured and purchased fertilizers will continue to be a necesary input-and the long term effects and sustainability of that model is doubtlessly familiar to all the regulars here.

If the biofuels industry really takes off, and society at large is still hooked on cheap energy, there is no reason so far as I can see that we will not run thru what remains of our soils and waters as fast and as recklessly as we have run thru our fossil fuels.

Beware the occasional idiot who posts links and proposes solutions to problems about which he obviously knows nothing at all.

They are mostly in the money, or dead on,and thier arguments may be summarized as "A farm is not an ecosystem".And even what we think of as a local ecosystem generally depends on the flow of some materials and nutrients into the area in question to replace those flowing out;even a stream in a pristine wilderness moves some soil, and animals living in such an area migrate and both import and export materials by doing so.

You nailed it you have to let the ecosystem first recover and then flourish.
In a flourishing ecosystem then humanity can live. First and foremost you simply have to get the population levels way down to allow the ecosystem to recover. Then and only then can this much smaller human presence integrate itself into the ecosystem not farming but claiming our own niche if you will like all the other parts.

If your only farming a particular piece of land every few hundred years then the issue is not really sustainable agriculture but recoverable agriculture i.e you don't want to permanently alter the land so it can't return to it natural state.

Obviously this means being a good steward of the land. Plenty of examples around the Mediterranean sea and other places where long term habitation has permanently altered the ecosystem as soils where lost to the point they will basically never recover.

What seems to be missing then is the steady creation and expansion of preserves.
Indeed this returning of the commons to Jevons seems to be the key.

Hi Memmel,

I do believe you have a pretty good handle on the fundamentals of agricultural conservation.I see only one problem with your proposed solutions, but it IS somewhat of a show stopper. :-(

How to we convince the human species ,which as Greenish so eloquently and succintly puts it, is perhaps rational on the individual level but irrational at the species level, to adopt such a radical change in THE WAY WE LIVE?

reading between the lines, I seem to detect a distinctly elitist flavor to the comments of our most dedicated environmentalists in a large majority of cases-I believe this is due to the fact that most of them are quite prosperous and believe that such changes as they advocate will not cause them any personal pain.

Most of us , however, speaking for the common run of mankind, don't have any extensive wiggle room in our live styles to speak of , and we will find it expedient to fight tooth and nail against a lot of worthy initiatives, even though such initiatives might be very good for us inthe long run; but we must survive in the short run.

there is no reason that a property can not be designed to attract wildlife (ie birds/bats etc) that will import guano for you.

Thanks Gail. This will become important in the coming years.

My food garden is in a clearing I made in the woods. I mulch with forest litter and add nitrogen with 1 part urine to 15 parts water. Water is from rain and a rain catch roof. I ingest very little salt (NaCl). There is an abundance of minerals in my clay soil but very little is readily available. My garden soil is better every year. How do I know: 1. better crop production, 2. more earthworms, 3. the smell, dirt smells like dirt, living soil has a rich aroma that you have to smell to appreciate. I use no commercial fertilizers and no pesticides stronger than marigolds and soap and water.

I don't find artificial ways to grow plants rather I find plants and varieties that grow well on my soil and in my climate as it is.

NO TILL. Pardon the caps but tilling brings deep micro-organisms to the surface where they are ineffective and buries surface micro-organisms where they are ineffective. Tilling also kills earthworms, a gardeners best friend.

Leave the roots of finished crops in the ground. The roots are food for earthworms and microorganisms.

Lasagna mulching. Put a layer of cardboard or many layers of newspaper over the ground before mulching with leaves, straw, compost, or other things. Great weed suppression plus, most importantly, earthworms love that damp paper.

"The footsteps of the farmer are the best fertilizer." So true, spend much time just looking over your garden.

This approach would not work for large farms but those days are numbered. As oil and natural gas decline "modern" agriculture will become impossible. A family with 5 acres or a clan with 40 acres will be wealthy.

I wish I could alter the coming nightmare but as the last sentence in Candide said: "We must cultivate our own garden."

6. Get rid of cemeteries. After you say your goodbyes to Uncle Jack and Grandma Doris, compost them.

But first take out their mercury-laden fillings. This is even more important if you burn them.

Let's just say I have a unique perspective in that I've been farming for twenty-five years and have experience with "traditional" farming techniques that ninety-nine percent of the people on this board don't have. My opinion may surprise you, though.


At home, we compost large piles of cow manure from our small grass-fed Devon herd. This gets mixed with leaves raked out of a nearby cemetery. We do this because we have it and it's essentially free. Who gives a crap whether it's the "right" thing to do? I want to live a good life, not save the world, which is not even mine for the saving.

Of course, the nutrients in the cow manure come from the fields down the road, so we're in effect robbing Peter to pay Paul when we use it to build up our 5,000 square feet of gardens, although we spread a whole lot of that manure right back on the fields each spring. Mixed into the field dressing is some wood ash we've accumulated over the winter, plus from our neighbor's ash pile, so we're robbing from the surrounding woods to perk up our fields. We're crooks and thieves, no matter how you slice it.

Oh wait--did I tell you that we are two over-fifty guys (who haven't reproduced), that we cut the hay ourselves with old, old equipment we have salvaged and repaired ourselves, that we collect the hay loose with an old-fashioned hay loader, that we drive it in a wagon right into the barn? No baler, no driving more than a half a mile to bring the hay to the barn. Give us a gold star for "environmental consciousness" and an appearance on Oprah's show. No wait--the truth is we're just CHEAPSKATES.


At the "organic" farm where I work, I'm in charge of a cool new composting facility. The materials are delivered by VOLUNTEERS who haul their own leaves to the site. The "green" matter comes FREE from a nearby college cafeteria, so it is 100% conventionally-grown plant matter from around the world that ends up in our compost. Then I use a bucket loader over and over and over to turn and turn and turn this compost until it stops stinking and it turns into a small heap of black matter that simply disappears into the land after I spread it. It is just shocking to watch all that organic matter dissolve down to humus, and I shudder to think of the embedded fossil energy in there from all the trucks that come and dump the stuff in the pile.

This is why, though I love this farm and my job, I don't subscribe to the "organic" rubric: it's a squishy term that allows for pineapple scraps grown by industrial farms in foreign countries to be counted as "organic" compost. God love those volunteers who do so much of our work for us out of the illusion that when they burn gasoline to deliver their leaves to someone else's compost pile it is a "virtuous" thing to do.

It seems like all nutrients must eventually be imported from somewhere else. Then we build our bodies out of these robbed nutrients, reproduce like bacteria, supply these new bodies with electronic devices, fly these bodies all around the world, drive them repeatedly across the country throughout their short lives, then bury them in copper containers after they wear out. Nothing is sustainable in the true sense of the word. We should have stayed in the trees.

I no longer even care whether what I do at home is "sustainable" or "organic" or "environmentally friendly." I've tried that shit for years, only to watch the population double in my lifetime and to watch my neighbors build large houses and buy big boats and SUVs.

F. it.

Yep, plenty of reasons to be bitter.

"Nothing is sustainable in the true sense of the word."

The things you mention aren't sustainable. And of course nothing will sustain for ever. But there are lots of other ways of living that can be sustained for a long time. Or could be, if we hadn't already messed so much of the whole planet up.

Ooops, back to bitterness, I guess.

Ooops, back to bitterness, I guess.

As Richard Pryor said, "Hope I'm funny."

Was that before, or after he set himself on fire with the crack pipe?

during :)

I know I have mentioned the connection between current organic methods and fossil fuel use.

Trying to do organic farming without fossil fuels will be a major step down from current practices, in my view.

the Organic Food Industry in the US runs on Diesel

You hit the nail on the head Mike, the only way to make ag sustainable long term is birth control.

The quicker corn-based ag goes by the way the better off we'll be - chicken should be for Sunday, ham for Thanksgiving and beef should come from grass.

Did you ever notice the same people who like to point out the due dates predicted by Malthus, Erlich, have passed are the same people who insist that since we haven't starved yet we might as well start using not only the main food crop for transportation to McDonalds but the "waste" from ag as well?

I agree with those who have said we know far, far more about the fundamental science of biology than we did 100 years ago, the trick now is to survive the bumper-sticker, book selling, gurus.

The problem isn't production, it's consumption.

ah mike B refreshing to say the least!! You know you could be using scythes to cut your hay, then you'd be eco angels!

Oops. Wrong topic.
But exciting anyway.
Laser Fusion optimism

And On Topic
Industrial strength worms

Worms eh?

The grand old man of worm'n is Edwards, Clive A. If you hear something about worms - check with Dr. Clive to see if it jives.

The 1st of (many) worm scams was back in the 1970's. One of the last ones was B&B worm farm which got shut down in 2003. Look also at the tax law - note how earthworm farming is not able to be written off.

One of the best style of bins is the OSCR
Oregon Soil Corporation offers for sale plans for their “OSCR” (Oregon Soil Corp Reactor) system

The system that has the most going for it BUT would require constant adjustment of the moisture level would be the worm gin. That level of babysitting should be checked out/confirmed before buying one. TerraCycle pictures can be seen with the gin they bought looking inactive. And they used to be sold by Jerry Guinn of What seems to be a winning path is you toss your wanna be worm food into a jet composter then in your OSCR. 3-4 feet high seem to self-regulate on the moisture.

Oxygen management in a bin matters. used to be a great resource. Now - not so much. If someone cares I'll dig up the page(s) from

The most common worms you'll find will be E. Foedita, L. Rubellus, P. Evactious, and E. Hortenis. (I didn't spell 'em right and frankly I'm not gonna spend time trying to get it right because I doubt any of ya care) L. Rub and E. Hort like a fungal diet so give them more leaves less green stuff. P. Eva are easy to spot - the egg band is quite near the head and the die at 45 or so deg so will only work where it is warm. (seems B&B worms had a lot of PEs they sold to ppl where the ground could freeze and said people lost their stocks) You can find EH's and LRs in gardens (EF's but they will be undersized) and William Kreitzer has the idea of taking LR's and adding them to the soil at time of planting.

And from vemipods a little something for ya all to regurgatate:

During World War II, the US Army Air Core sprayed anhydrous ammonia (NH3) on the dirt to make runways for our bombers. Spraying NH3 on the dirt killed all the microorganisms in the soil and made it like concrete.

After spraying it they noticed that the over spray caused the vegetation to grow. Henceforth, a new fertilizer had been discovered.

Sorry - the National Ignition Facility isn't that exciting unless you want to maintain H bombs. Which is what the purpose of that facility is. Back to topic - my personal answer, as unpalatable from a policy perspective as it is, is to stockpile compost and manure. I'm looking forward to getting several years worth delivered this spring. I'll figure out how to close the loop later - my primary goal this year is to continue expanding my gardening and canning efforts.

Keep pigeons.
They harvest nutrients from far and wide and deliver it to your garden.

Might work somewhat until "far and wide" gets hungry....

Fun to read many of the comments here. As one who grew up on a non-industrial farm, I find OldFarmerMac's comments above highly recommended. I still remember farming our 120 acres of heavy clay at Lat 55 North with horses only, except for the visit of a threshing gang once each fall. Among the things I learned: a) how little I know about what it takes to maintain such a system in a condition capable of supporting a family of 6, even though I possess sufficient facitity with test-taking to win scolarship entrance to honours science at a prestigious university. b) how hard the work is. Suffice it to say that when we boys got old enough to work summers at labour off the farm, even the heaviest labour jobs were like a vacation. c) how little most "experts" actually know about relevant matters.

Anybody making definite predictions about the future is either providing reasonably acurate statements about the odds of their predictions being completely wrong, or they haven't a clue about what they are talking.

Unfortunately, my father had a green thumb, but never passed it on to me. It wasn't his fault. Anyway, when things get really bad, maybe I'll just start carving tombstones for a living.

Anyway, when things get really bad, maybe I'll just start carving tombstones for a living.

Perhaps while you are at it, you could also convince the bereaved to bury their dead in bio degradable jute caskets and plant fruit trees above them. Then you'd have a nice little fruit orchard with decorative carved stone markers. Win win!

However, I do like the irony of carving tombstones for a living ;-)

Hi Gail,

Thanks for a very interesting topic. My brief reading of the topic seems to indicate there isn't really a lack of these basic macro-nutrients, but rather a lack of soluble or usable nutrient forms. Generally speaking, adding organic matter to soil increases availability of P and K through creation of organic acids in the soil to break down parent material, and by improving cation exchange capacity. Healthy organic soils require much less P and K inputs than sterile industrial ag soils. The process can be helped along by planting recycling plants such as bracken fern, comfrey, docks, etc. Many weeds indicate soil nutrient constituents and deficiencies.

On the topic of Nitrogen Fixing Trees (NFT) there's a great book by J. Russell Smith called Tree Crops: a Permanent Agriculture. The title was one of the foundations for the idea of Permaculture.

Here's a short list of NFTs I grow in the northeast. I'm on 0.4 acre:

  1. italian alder
  2. thornless honey locust- I live on Locust St.
  3. black locust
  4. mountain ash
  5. white ash
  6. pagoda tree / scholar tree
  7. redbud

I use a lot of shrubs and forbs as well such as clethra, siberian pea shrub, runner beans, peas, edamame, beans, alfalfa, clovers, etc.

In warmer climates there are many forms of acacia. On the west coast and southwest, mesquites fixes nitrogen. It also turns out there are nitrogen-fixing lichens that grow on bark and stone.

Also, I seem to remember reading in Pimentel about studies showing Coprosma interplants raised corn yields by 30-80%, so nitrogen fixing can be done on a large scale.

The reason this isn't done on a wide scale now is that it is cheaper to buy ammonia (made from natural gas) than it is to buy legume seed, plant it, and then till it in as green manure. When ammonia fertilizer prices skyrocketed in 2008, legume fixed nitrogen looked competitive. Mind you, this is only on a N for N comparison. Cover crops do a lot more for the soil but these costs aren't usually considered when farmers are thinking about yields in the short term.

1. What approaches are you using for maintaining phosphorus and potassium levels?

In a Permaculture approach, we are using lots of animal manure, using a paddock rotation system. We also put all residues back, sow "green manure" nitrogen-fixers like clover, and plan to implement humanure soon.

2. How scalable are the approaches you are using? Could they substitute for the current rock-based fertilizers?

Completely! Any organic farmer will tell you so!

3. How do you deal with the issue of too many of some nutrients in manure--for example, for sweet potatoes, when you don't want the tops to grow too much, and for legumes, when you don't want to encourage the weeds?

Composting. You generally don't use fresh manure. We watch our C/N ratio in our compost, so we don't go overboard on nitrogen.

4. Have you tried using nitrogen fixing trees? How about phosphobacteria? Is there an expert on either of these subjects that would be interested in writing a post?

Yes, we're starting to. We're putting in a coppice "green screen" between us and the road, of willow, maple, and alder. The alder is considered by many to be a "trash tree," unfit for building or burning, but it feeds the other trees. We plan to cut this in a 5-10 year rotation to use as heating fuel and basketry.

At the edge of our neighbour's hay field, you can plainly see a band of greener hay that extends perhaps 4-5 metres from where the alders, a pioneer species, have started taking over the hay field.

5. Are you using humanure in your fertilization program?

We are not doing this yet. There are huge social stigmas associated with this! So when we start doing it, we're going to be very quiet, and if anyone notices, we'll assure them it is for non-food fertilizer only. (And hope they don't look around and notice that we don't have any ornamentals... :-)

By the way, phosphorous is by far the one to worry about. Nitrogen and potassium are relatively easy to recycle, but as long as we sh*t in our drinking water and flush it out to sea, we're going to have a looming phosphorous crisis.

"With your intensive agriculture," he went on, "you're simply draining the soil of phosphorus. More than half of one per cent a year. Going clean out of circulation. And then the way you throw away hundreds of thousands of tons of phosphorus pentoxide in your sewage! Pouring it into the sea. And you call that progress. Your modern sewage systems!" His tone was witheringly scornful. "You ought to be putting it back where it came from. On the land." Lord Edward shook an admonitory finger and frowned. "On the land, I tell you." -- from Point, Counterpoint, by Aldous Huxley

6. Are there approaches I have missed?

I think you only mentioned wood ash in passing. It's a tremendous source of potash, but you have to watch your pH balance very carefully, as wood ash is a strong base. That can work well if you have acid soil, but it's easy to go too far the other way, which shuts down the transport of minerals.

By the way, if I might make a quick plug: our farm co-op is in a financial crisis, and we are seeking an equal partner to fund half the co-op, which will get you a five bedroom house to live in and equal access to our 30 acres of irrigated Class 2 soil in growing zone 8+, on a lovely Canadian island. More info here. (Sorry if this is inappropriate.)

"2. How scalable are the approaches you are using? Could they substitute for the current rock-based fertilizers?"

Completely! Any organic farmer will tell you so!

Well, I'm glad you asked! Although I personally repudiate the "organic" label, I do work at a very nice "certified" farm.

Your statement "completely" is completely false.

Even with compost, with have to go through bags and bags of rock phosphate each year.

Now this is "certified," virtuous rock phosphate, not the "evil" kind, super phosphate, which is damned for having been heated.

If you're not getting phosphate from rock-based "fertilizers," then where are you getting it? Animal poop? Human poop?

And where are the animals and people getting it? That is, how do you get the phosphate into the turds?

You pass a wand over it and click your heels three times, that's how.

When that fails, we can always mine Ezekiel's valley of dry bones.

Reading some of these very fine comments has got me to thinking of writing a short piece called something like "The Thinking Deer of St. Mathews Island". These smart deer, once introduced to the island, would first run around, checking the place out. Then, they'd sample all the food, including the seemingly abundant lichens growing there. Noting the spatial distribution of these lichens, and their species, the elder herd members would recall that those particular lichens only grow at a few cm per hundred years, and then they would calculate how much time it would take for each deer of the herd to go through a reasonable replacement allotment. Since the growth rate of the lichens is so alarmingly slow compared with the short lifespan and voracious appetite of the deer, they would conclude that it would be like mining a fossil fuel, oil or coal, for example, and using it for a staple food source. Or even using up a one-time gift of glacially accumulated topsoil or abundant fresh groundwater stored from the last glacial epoch. The elders would then caution the rest of the herd only to eat small amounts, if any at all, of the lichens, and instead concentrate on the faster-growing grasses and tree bark available, even though less abundant. The herd would be small but would at least be sustainable, and although it would be rough, a few of them could make it there for a seemingly long time after the kindly humans had placed them in their wonderful new home without any of the usual nasty predators or hunters. The end.


These smart deer, once introduced to the island, would first run around, checking the place out....etc.

Thank you for making my day.

Russian oil production increased in jan/feb.

It would be very helpful if we simply got the phosphates out of the detergents and thus conserved them for agricultural use. I can't believe that this late in the game, laundry and dishwasher detergents are STILL being sold that have phosphates in them. GOOD GRIEF, that was one of the very first issues that the environmental movement addressed. I remember a very big deal being made of these, and the eutrophication they were causing in lakes and streams, back in the late 60s and early 70s. That was a long time ago, and yet we still have detergents with phosphates in them!

I wish to address a couple of responses to my original comment:


I don’t mean to disagree for the sake of it but there is considerable evidence that prehistoric man ate considerably more meat than us and had the body of world class athletes. Carbohydrates, especially those from your so-called whole grains, were an utter disaster for human health on every level.

As for the two minutes of research you say I should do, I did a whole week of research in 2002, dropped my ‘healthy’ green diet for 6 eggs a day, butter, steak and all the rest. The result? A 20kg loss in 3 months and the bulking up of muscles without losing weight at the same time.

In addition, except for walnut and flax seeds, all the other oil seeds have very high omega6 levels, which will further exacerbate EFA imbalances. Wild fish is the only high quality omega 3 source and it is getting scarcer every day. Fishmeal is being rationed in farmed fish, undermining their EFA fundamentals.

Your statement that “I speak as a first worlder” is far more uninformed and ridiculous. I have lived in 4 East Asian countries over 12 years and presently live in a common man’s neighbourhood in the middle of Singapore. If you want to know how the second and third world lives, uses and wastes energy, feel free to ask without assuming first.

As for tilapia, it has practically non-existent Omega3 fat levels and in many places you will find it farmed in near sewage conditions, with antibiotic overdoses holding nature at bay.

Beyond that, critics are my greatest teachers and I appreciate your input.


I know exactly what you are talking about having done a TON of research on the topic. I know all about DHA and EPA and ALA. I realize that very few people actually get any EPA/DHA in their diets. What you have wrong is that they don't come from fish, they come from what the fish EAT, which get it from algae. Diets today are sky high on omega 6s (fall fats) vs omega 3s(spring fats). There is a reason that in those secluded African tribes that after they kill a bonobo or monkey they suck out the bone marrow and eat the brains. Both are very high in DHA omega 3s. I do think that growing algae on a wide scale in the desert could yield a cheap source of omega 3s without killing off all the fish (i believe that the omega 3s added to children formula are made in a centrifuge?) I know they are genetically working on a corn? variety that produces omega 3s. Another beef i have is with Vitamin D and how deficient large portions of the population are. We probably should have stayed in the trees, in the tropics!

Pee and Poo is food for plants...

Just ran across a report from a IISD, a Canadian environmental organization, on Peak Phosphorus.

Press release (posted at EB)

Peak Phosphorus: Opportunity in the Making—Why the Phosphorus Challenge Presents a New Paradigm for Food Security and Water Quality in the Lake Winnipeg Basin (18-page report in PDF)

- Bart (Energy Bulletin)


The role of algae, plankton, etc. in supplying omega3 is a great point I overlooked. In that respect, the questions become a) how do we incorporate algae, etc. in the food supply in a way that preserves their omega3, which oxidises easily (b) how much phosphorous/potassium does the algae require? Can we increase the omega 3 content without putting further strain on fertilizer feedstocks, natural gas, etc.

The effect of UV on vitamin D levels is real. After keeping a constant sun tan, I've only suffered colds/fevers every few years. Before moving out here to Singapore, it was every few months.

One interesting thread on the oildrum from a few years past was the possible substitution of solar power in place of natural gas in fixing N-P-K for fertilizer but I can't find it now.


Just to let you know, Monsanto is developing a type of soy that produces omega3 "without having a fishy smell" (to quote their PR statement). I did an article on genetic engineering where the Asia president refused to say if the omega 3 produced would be EPA, DHA, ALA or a combination thereof. Despite my commercial relationship to the grain and livestock industry, I do have personal reservations about genetically produced omega 3.

I'd rather we make it the old fashioned way, with wild catch, fishmeal, algae, etc., even if it uses more energy and scarce elements.

While on the subject of soil phosphorus: here's a
rather long-winded exposition that might be useful,
regarding the (apparently profound) potential influence
of termites, and ants, on the stuff:
Cretaceous Termites and Soil Phosphorus
by Charles Weber