Reducing Fossil Energy Use on the Farm

This is a guest post by James Giese, Director, Science Communications, American Society of Agronomy.

Conventional production agriculture relies heavily on fossil fuels, particularly in its ability to provide high yields at low labor costs. However, the uncertain future of fossil fuel availability and prices point to a need to explore energy efficiencies of alternative cropping systems. Although more labor intensive, low-input cropping could substantially reduce dependence on fossil fuels while maintaining comparable yields.

Most of the U.S. Corn Belt relies on a 2-year rotation of corn and soybean with heavy inputs of fertilizer, herbicides and pesticides derived from fossil fuels to achieve high yields while keeping costs low.

To better understand energy inputs in all cropping systems, Matt Liebman, Michael Cruse, and their colleagues at Iowa State University conducted a six-year study to compare energy use of a conventionally managed corn–soybean system (a two-year rotation) with two low input cropping systems that used more diverse rotations and manure, but substantially lower quantities of nitrogen fertilizer and herbicides. The study will be published in May-June issue of Agronomy Journal, published by the American Society of Agronomy.

The two low-input systems, which use lower levels of purchased inputs such as fertilizer and fuel, consisted of a three-year rotation of corn–soybean–small grain/red clover and a four-year rotation of corn–soybean–small grain/alfalfa–alfalfa.

Did the replacement of fertilizer with manure decrease the fossil fuel energy costs? Manure prices are dependent on local economic conditions, and depending on how fossil energy costs were assigned to manure, the two low input systems used between 23 and 56% less fossil energy than did the conventional system.

During the course of the study from 2003 to 2008, nitrogen fertilizer inputs were reduced 66% in the three-year rotation system and 78% in the four-year rotation system compared with the two-year system. Herbicide use was reduced by an average of 80% in the three-year system and 85% in the four-year system.

Despite the fossil fuel reductions, corn and soybean yields in the low-input three- and four-year systems matched or exceeded levels obtained from the conventionally managed two-year system. Crop yields in all of the experimental systems were similar to, or greater than, mean yields of commercial farms in the surrounding county in all years of the experiment.

According to Liebman, the two-year corn-soybean rotation is typical of cash grain systems in the region of Iowa that was studied. The three- and four-year rotations are representative of low input cropping systems in the region that are integrated with cattle production through the feeding of crops to livestock and the application of manure to crop fields.

“Iowa has a long history of mixed crop and livestock farming, although these operations do require more management and labor,” said Liebman. “If fossil energy costs rise steeply, we may see more of them again.”

The researchers used two approaches for evaluating the energy and economic costs of manure. In one approach, manure was considered a waste product of a livestock operation and its only energy cost was the energy used for its application. Similarly, for a low economic cost scenario, manure was regarded as free except for application costs (labor, tractor fuel, and machinery depreciation).

The second approach included both the energy costs of manure application and the energy costs of manure nutrients assessed as if they required the same amounts of energy used to produce commercial fertilizers. Similarly, for a high economic cost scenario, the cost of manure was set as the application costs plus the cost of nutrients within the manure set at commercial fertilizer prices.

The researchers noted that the real energy and economic costs are likely to lie between the low and high extremes they analyzed, and will vary depending on market conditions and the configuration and management of the livestock operation generating the manure.

When considering manure as a low-cost economic input, the researchers found that the monetary return to land and management was similar for all systems, averaging $249 per acre. Using commercial fertilizer prices for manure nutrients reduced returns by $38 per acre for the three-year rotation and $28 per acre for the four-year rotation.

Most of the fossil energy input for all systems was from grain drying and handling. Conditions in northern latitudes, where farmers have limited time to allow grain to dry in the field, make it difficult to reduce this cost. The researchers point out, however, that growing corn less frequently in a rotation sequence can reduce the need for grain drying with fossil energy.

A major trade off is that the low-fossil energy input systems require more labor.

Efficiency ratios, including crop energy output and economic return per unit of fossil energy invested, were significantly higher in the low input four-year rotation than in the conventional system. Most of the variability observed among systems in energy use efficiency was due to differences in fossil energy input values, not in outputs from the systems, since productivity of the systems was essentially equal. Incorporating alfalfa into the four-year rotation was important: in all economic analyses, the four-year rotation was significantly more efficient in energy use than the two-year rotation, while the three-year rotation was not.

In this study, labor inputs followed an opposite trend to that seen for fossil energy inputs, with the four-year rotation having the largest labor inputs and the two-year rotation having the smallest. As compared with the two-year rotation, which required 41 minutes per acre per year, the three-year rotation required 54% more labor, while the four-year rotation required 91% more labor. However, the incorporation of small grain crops (triticale and oat) and alfalfa into the low-input rotation systems placed much of the extra time investment into parts of the year that did not overlap with peak activities associated with corn and soybean production.

The researchers suggest that historically low energy prices during the 20th century, along with relatively high wages in the United States, have contributed to widespread adoption of energy-intensive farming practices. The team says that their analysis shows that the conventional two-year rotation system widely used in the central U.S. (corn-soybean) relies on fossil energy to reduce labor requirements while allowing net economic returns to remain constant. This provides greater wage rates for the producer. However, the researchers claim, diversified low-input systems can provide greater returns per unit of fossil energy invested, even though overall returns from the land are similar to the conventional system.

In coming years, the market prices from cash grains will play a big role in what cropping systems will gain favor in the U.S. If demands from ethanol plants or overseas markets increase the price of corn grain faster than input costs rise or if commercial-scale production of biofuels from corn stover becomes economically viable, Midwestern cropping systems might become less diverse and more focused on corn. Alternatively, if fossil energy prices rise significantly without simultaneous increases in crop value, diversified low-input cropping systems, such as those described in this study, may become preferable to conventional cropping systems and used more widely.

“It’s hard to predict the exact details of what the future will bring us,” said Liebman. “But results of this study show that we do have options for maintaining high farm productivity and profitability while substantially reducing our dependence on fossil energy.”

The research team, funded by the Leopold Center for Sustainable Agriculture and the U.S. Department of Agriculture, is expanding its activities with measurements of effects of the different cropping systems on water quality, greenhouse gas emissions, and soil carbon and nitrogen dynamics. They will also investigate the economic consequences of integrating crop and livestock production in different ways.

Material adapted by James Giese, Director, Science Communications, American Society of Agronomy (URL: ), from:

Fossil Energy Use in Conventional and Low-External-Input Cropping Systems
Michael J. Cruse, Matt Liebman,* D. Raj Raman, and Mary H. Wiedenhoeft
DOI: 102:934-941
Published online 24 Mar. 2010 in Agronomy Journal (URL:

Excellent article, James; thank you Gail for bringing us this perspective.

A few questions James;

1. Were any of the cases you examined free of methane-based nitrogen fertilizer or was the manure offsetting just a portion (i.e., 66% and 78% in the first two examples)?

2. What are your thoughts the energy difference be between the grain-based livestock feeding approaches you identified and a grass-based livestock production approach? Studies point to the latter requiring far less net energy input and producing a healthier consumer product.

3. What do you think of the use of air and/or solar grain drying processes?

4. What do you think about the method of using nitrogen fixing cover crops between crop cycles (i.e., planting red clover post-harvest to suppress weeds and add nitrogen until the next year's crop is planted)? (along with current practice discussion)

Thanks for the links. More evidence that the most important energy flow for civilization and its continuence is in our heads.

One of the great errors of the give-up-we're-doomed crowd is to presume that the population explosion of the last two hundred years was the effect of the use of fossil fuels in agriculture. Another great error in thinking is the presumption that the inevitable decline in fossil fuel supply translates into an inevitable decline in agricultural productivity.

Populations increased with the application of innovations in science, including important new understanding of disease and how to deal with it. Farmers responded to increased demand with increased production. Fossil fuels served the production increases because they presented the most cost effective, in the short and medium run, means to increase food production. Not because they were ever the only way to increase production.

The surest route to avoiding starvation is the continued application of intelligence, while we disengage from the application of fossil fuel derived products.

The surest route to avoiding starvation is to avoid overpopulation, but for many of the countries of the world, that is too late. Agreed about the error in thinking that world population growth has been caused primarily by mechanised farming. if you look at all the countries that have had the greatest population growth (Asia, Africa) they are generally the least mechanised. They have had growth because of reduced mortality rates.

toil and Paul: the Green Revolution was a package -- mechanized agriculture, better fertilization, improved plant varieties, etc. All of these things came about since the end of the Second World War and the improved nutrition that the Green Revolution brought allowed populations to boom, even in countries where Western-style mechanized agriculture was not the norm. Cheap fossil fuels and the petro-chemical industry that they gave birth to were indeed central to population growth in these countries. Say what you will about what the future holds, but the exponential population growth of the second half of the 20th century was fueled by petroleum and the things that it made possible.

The so-called green revolution is precisely an example of using intelligence to develop techniques to increase food supply to meet demand. Doing taxes at this moment (Canadian) and can't remember the name of the scientist considered the 'father' of the 'green revolution', but check out his story and you will see that his motivation was not to expand the population, but to meet existing and anticipated demand for food.

That the architects of the new agricultural technologies assumed fossil fuel inputs, is a result of the low cost and the, then, apparently 'vast' supply of these inputs.

What I'm saying is that all else being equal, except no fossil fuels this side of the moons of Jupiter, scientific advances would have resulted in greatly increased populations (given the inertia of cultural tendencies towards large families in many regions) and that farmers would have met this demand thanks to the application of human intelligence to the problem. Folks might want to read the biography of James Hutton, the man generally credited with the discovery of deep time and sometimes called the father of geology, a contemporary of Adam Smith, James Watt and other figures of the Scottish enlightenment, who developed techniques to restore the agricultural productivity of depleted Scottish soil long before fossil fuels had anything to do with farming. Improving soil and increasing yields is work not only of the back, but also of the brain.

There is a naive idea in circulation that evolution, individual or social, is a result of a starve or evolve choice. I believe science reveals that all of nature adapts to opportunity. Farmers certainly do.

Oh, certainly, soil husbandry predates industrial agriculture. There are numerous examples of highly productive soils worldwide that have been farmed for centuries -- long before the Green Revolution. In fact, some would argue that industrial agriculture is the worst thing that ever happened to soil husbandry.

That said, you can't discount the importance of agrichemical inputs -- particularly synthetic fertilizers and lime (which, though it is a natural product, would not be widely available without cheap energy, either to mine or to transport it long distances). If you look at historical gains in grain output (and in world population growth), the big leaps came after WWII. I have to respectfully disagree with your contention that world population growth had nothing to do with a mechanized, petroleum-based agricultural system.

"In the 1960s, rice yields in India were about two tons per hectare; by the mid-1990s, they had risen to six tons per hectare. In the 1970s, rice cost about $550 a ton; in 2001, it cost under $200 a ton. India became one of the world's most successful rice producers, and is now a major rice exporter, shipping nearly 4.5 million tons in 2006. (Green Revolution)"

BTW, I think you're speaking of Norman Borlaug -- generally acknowledged as the father of the Green Revolution.

I think the problem with the Green Revolution, is that it did increase yields, but the populations have expanded such that (almost) everyone is still hungry in those places. It is the human equivalent of an algae bloom.

Also,what it has not done is made those countries any wealthier, it has merely spread the wealth amongst a greater population. Post war, Kenya was one of the richest countries in Africa, with a relatively good standard of living. Now it is an overpopulated basket case, as are many other African countries.

For those peasant farmers in India, they have to produce 550/200 = 3x as much rice to make the same living as they did in 1970 - they can never become anything other than subsistence farmers. India exports rice, but people in the northern provinces are starving, but to reduce exports reduces much needed hard currency income. The green revolution there has enable the country to make money off agriculture, and even be food self sufficient, but that does not mean everyone has benefitted.

Solving the problems you raise, Paul, requires a revolution of a different colour....

In certain parts of Africa that I have been, the growth AND lack of mechanization come from free food given out by various UN sponsored and 1st world sponsored organizations. And I would agree it is too late for them, as I've told my African friends, I'm unaware of any civilization lasting very long without truly securing its agriculture (Romans taking Egypt
would be an example).

I tend to agree with this. Science has been great at reducing child mortality and industry has been great at feeding the children so that they all grow up to have more children, who also don't die and grow up to ahve even more children etc, etc. It is an artificial and highly unstable arrangement that only works because of the fossil fules that have been avaialble and applied to the food supply, just not in the same areas as the population booms.

Without the food subsidy, many Third world populations would have had naturally regulated populations, however brutal it might have been for the individual humans concerned. By robbing nature of its main tools of population regualtion, we have created the circumstances for an even more devastating nautral cull when the artifice is withdrawn.

Do-gooders who want to cure AIDS and cancer and malaria etc are ultimately fighting the new weapons that nature has evolved to deal with the plague of humans.

This is a difficult subject emotianlally for many people to deal with and is therfore often avoided, particularly when it can be seen to come from a western ivory tower pronouncing judgemnt on the teeming masses of poor in the third world. But deal with it we must as it will only be through honest examination and compassionate assesment that we can find the safe path down for everybody that does not involve brutal racial wars or perpetual misery for many of the worlds poor. Returning to traditional local agriculture is going to be part of that mix so that all people around the world are largely occupied with farming rather than fighting. The greatest sacrifice may need to be by western farmers. My heart is bleeding already....

I agree with most of the things you are saying. Compassion can lead to unexpected calamity but don’t blame those trying to help. There must be a solution. Sterilization for those receiving gifts of mercy for population control in any country could reduce population to a manageable level. Of course China tried this and western news outlets all screamed of the cruelty.

If it were not for the western farmers the poorest nations would starve but so would those living in large cities in the United States. When that occurs city dwellers will go to the country side looking for food. It wouldn’t take long before the U.S. would have a total break down of society.

Last week a TV program was discussing new weapons developed by Homeland Security. Blinding lights, sound devices that would incapacitate people, slime that would cause a person to lose traction, and pepper spray that could be stop a large group of people. All for crowd control. Why does Homeland Security want crowd control weapons? Why so much talk about home grown terrorist? Are we on the edge of something terrible?

I think it is wrong to say that population increase of the last 200 years was the EFFECT of fossil fuel use in food production. I think population increased because the rate of growth was allowed to follow its natural progression, but in an environment that allowed for (relatively) unfettered growth. If you take an extremely low rate of growth but greater than 1, say 1.01%/year (or 1.001, I did it a while back but forget the decimal place) and allow it to expand normally, ultimately you get the population accretion you see today. You might consider our developing fossil fuels and improved agricultural technology as a form of 'just in time' delivery. But, as is very obvious, it cannot last.


I also enjoyed this article as it points to some of the adjustments that will inevitably take place when the (fossil fuel / human labor) price ratio in developed nations rises from its recent historic lows.

I'm sure many other endeavors can and will substitute human labor for fossil energy going forward but it may take some outside-the-box thinking to imagine what they will be. Lowered consumption of long-lived items with a higher quotient of 'craftsmanship' is already becoming stylish among today's urban youth.

Best Hopes for valuing human craftsmanship!

-- Jon

"Report: 'The Big Fat Lie about Doubling Food Production'
UN Based Policy of Doubling Food Production on 'Flawed Data'"

"However, using the FAO's own figures, the Soil Association says the forecast increase needed in production would be closer to 70% by 2050."

This at a time when arable land expansion is leveling off and starting to decline;

"The report also questions assumptions made in the FAO report concerning, among other things, high levels of food waste and billions more people eating western-style diets that are high in meat and dairy products, which have been linked to obesity, diabetes and other health problems."

Please note that the Soil Association is not saying that a 70% increase in food production is needed.

These claims of a 'need' for a dramatic increase in food production are coming from individuals with agendas, not the least of which are the parasites who are looking to ride corporate food manufacturing to a life of ease.

"The FAO report, World Agriculture towards 2030/2050 says world food production growth would be principally driven by rising populations, and trends towards eating more calories and more meat and dairy products, especially in developing countries. As a result, the FAO forecast an average 1.5% a year growth in agricultural production by value from 1990 to 2030, and then 0.9% a year for the following two decades to 2050."

They forecast production based on demand.

What is 1.5% for 40 years, or 10% for 40?

and if you read the other link it shows that all aspects of food production world wide are flat lining or declining; water, arable land, productivity per acre, and on and on.

Although I applaud the author and agree 100% with the methods described, what I am saying is that the problem is quite a bit bigger than the feature post portrays it to be.

The problem lies with the assumptions in the demand forecast, a point made by the Soil Association. The SA then points out that even using these assumptions, the FAO has made a very significant error.

Since we all seem to revel in predictions, here is another: within a decade or so, public information campaigns promoting moderation in meat consumption, particularly red meat, will be commonplace. Advocacy for the application of sin taxes on manufactured red meat will be heard on campus and in church. Hollywood stars will be seen with a little buffalo meat mixed with their beans.

Give me a break, we're not going to stop eating meat. People with less money will just not be able to afford eating it so much. Turning the U.S. into some sort of Soylent Green nightmare where they freak out over meat would not be popular. If the third world cannot afford food -- too bad. If people are freaking out over meat we'll be well on our way back to the Olduvai gorge.

You misread his sentence;

"...campaigns promoting moderation in meat consumption, particularly red meat, will be commonplace."

Absolutely nothing there about "stop eating meat" or "Soylent Green". Where do you get these from in his post??

I think it's worth remembering that there is a lot of money invested in the corn/beef industry in this country (USA). They won't give up without a fight.

I'm going to happily continue eating ethically-raised, non-confinement bacon, regardless of the price. If it gets too expensive I guess I'll just have to charge celebrities $10,000 a week to stay at the net-energy-producing, integrated livestock/biofuel/windfarm/crop operation. I'll have to make sure it's good bacon before I serve it ;)

Being a hick farmboy is starting to look to be quite a good thing these days.

You are the future. Good on you.

The bizzaro world of official government forecasts is certainly based on assumptions of continued economic growth AND the demographic transition--and these are related as demographic transition itself require the material gains associated with economic growth. This is not just true for energy (e.g., IEA and EIA) and carbon emissions (e.g., IPCC) but also food demand growth (e.g., FAO).

If we focus on sufficiency of food the numbers turn out very different. Even today enough food is produced to feed 9 billion people. That is one reason why population continues to rise, i.e., food supply is a carrying capacity signal and all indications are we have plenty of food.

The fact that about 1 billion people are undernourished even with this over-supply is another fascinating topic.

Rather than worrying about farm-level productivity, I am more concerned about the energy in processing and distribution, the social strains of a faltering economy and ability to invest in a transition, and long-term soil health, which could be eroded by just more of the same dumb policies in place and a greater rush to biofuels.

That last one is most important in my book. We need the soil to be in great shape. This is our natural capital base and nothing else of value in society is possible without good soil.

A lot of thought-provoking material in here for people trying to think about the future in terms of systems. The one that jumped out at me was that most of the fossil energy inputs were for grain drying and handling. Does long-term decline in natural gas supplies imply significantly higher spoilage rates (hence lower net yields) for grains?

Mr. Giese, thanks very much for the article. It's good to see a posting from a fellow Madisonian (I live a few blocks away from your old digs on Segoe Road).

Like mccain6925 and Will Stewart, I was also struck by the high inputs for grain drying and handling. How about using farm-derived biomass (straw, corn stover, whatever) as fuel to drive the drying process?

Your suggestion is alive and well in countries that have a forest products industry.

The Scandinavians, Germans and Austrians all use wood chips (quaintly named Hackschnitzel in German) for a sizeable fraction of both industrial and household heat. (Sorry, no numbers.) Organizations such as the Danish Center for Biomass Technology are promoting the use of both wood and straw as raw material to fire power plants and have excellent documents in English. All of the above nations have also embraced district heating which seems to be a natural fit for use with biomass products.

It seems inevitable that farm waste will be used in the grain drying process in the US just as soon as it becomes cheaper than natural gas. But that might take a while.

The Europeans have done well with thier combined system of power production and district heating and I hope to see this technology widely adapted here in some parts of the US soon.

It might work to some extent in some places in farm country, but my guess is that the price of gas will have to go up a lot for it to happen, as this process would require a big investment in time and capital.An individual farmer would need the system for only a few weeks out of the year, and have to look after it at a time when he is normally very pressed for time-during harvest season.There would be little point in investing in electrical generating equipment-he would not have much if any need for this temporary power, beyond driving the fans and augers of his drying equipment.

Now if several farmers could get together and build a community sized system, the economies of scale might favor success.

Bottom line , my guess is that eventually we will see combined heat and power systems on American farms, but that we won't see them for a long time.The existing gas fired systems are basically sunk cost and other than obtaining and paying for the gas,a farmer has no incentive to change to a new system.

Of course an enterprising farmer with access to plenty of dry straw or waste wood might jury rig a burner using these fuels to his existing drying equipment and thereby cut his gas bill substantially.

I'm not at all worried about starvation here in the US due to a failure of the industrial ag system,absent a mad max economic crash.Agriculture just does not require that much fossil fuel , and as the author has amply demonstrated, there are ways of substantially cutting the amounts currently used by substituting labor and changing the crop mix..

The thing that worries me, and that should worry everybody who is reading the Oil Drum, is our love affair with the personal automobile.If it becomes possible to produce ethanol, or any other biofuel for that matter, in large enough quantities to convince the public that we can continue have an ICE car culture,I have little doubt that collectively we will make the decision to do so.

If that happens, the mouth pieces of bau will convince Joe and Suzy Sixpack that corn stover and wheat straw and tree laps(the parts usually left to rot by loggers) are simply trash provided by God and the (nonexisistent)free enterprise system to meet our fuel needs, and of course the economics profession will see this as vindication of thier beloved substitution theories.The politicians will stick a wet finger up into the wind, and play along.

If the cards fall this way, it will probably be impossible to reverse course once to the biofuel and automobile culture marrige is consummated and produces a baby or two in the form of a biofuel industry with REAL muscle.Today's ethanol industry is just a bastard( er , excuse me, love child) toddler, and does not yet employ large numbers of people and does not operate except in corn country.

We have more than enough problems with maintaining soil fertility and clean water supplies as things stand today, not to mention the loss of prime agricultural land to sprawl.

We will furthermore have a hard time saying no to all the countries that want to import our food before too long ,in exchange not just for throwaway consumer junk but rather oil and other increasingly precious minerals.

A real collapse of agricultural productive capacity could occur unless we somehow manage to stop the rush to biofuels by embracing conservation, efficiency, and life style change.You can only work a horse so hard before he dies on the job.

Of course as the economist said, we are all dead anyway, in the long run.I won't be here to see the countryside stripped bare so dimwits flush with cash can burn a gallon of 200 proof in a four thousand pound car to fetch a pint of alcohol in the form of beer......

Of course an enterprising farmer with access to plenty of dry straw or waste wood might jury rig a burner using these fuels to his existing drying equipment and thereby cut his gas bill substantially.

Quite possibly, but at a substantial increase in complexity. LPG burners are such marvelously simple things by comparison. Straw or equivalent needs to be collected and transported. For a continuous-feed dryer, the burner will have more moving parts, in order to deliver fuel and extract the ash. Several of the current grain dryer designs appear to mix the flue gas and outside air to temperature and blow that directly through the grain; a biomass-fueled burner would almost certainly need a heat exchanger in order to eliminate the chance of burning residue coming in contact with the grain.

There appear to be a number of people fooling with corn-fired grain dryers. If the grain being dried is corn, it appears that you would need to divert about 2% of the corn to fuel the dryer. Some analysts have calculated that at current prices, that much corn is cheaper than the equivalent LPG.

Hi McCain,
Exactly right! Such a jury rig would most likely be useful only when the time needed to look after it is readily available, such as when the weather is too wet to continue the harvest, or after the harvest is finished.

If properly designed it would most likely use a heat exchanger to preheat the cool air entering the gas fired portion of the drier, so that the gas burner could run either at a lower constant rate, or intermittently.That way when the jury rigged burner runs short of fuel,and there is nobody around to stoke it,the drying process continues on uninterrupted by the automated gas burner.

Burning corn does seem extremely wasteful, but it can work in terms of dollars and cents.People who raise corn can often burn it cheaper than they can buy an equivalent amount of other fuel.

This is a good example of what X is talking about when he says it is not possible to compare different kinds of things in terms of energy.He hasn't posted anything recently; he is probably pretty busy right now.

But to the best of my knowledge, the people who have bought residential corn stoves and have to buy thier corn in bags at retail mostly wish they hadn't.Corn prices have a way of doubling or better between the elevator and the retail cash register. The ones who live in corn country may still be able to get corn cheaper than fuel oil or propane.

There are fireplaces and boilers made for corn (similar to pellet ones). No doubt you could find a corn "furnace" if you looked for one.
Lots of info here

Energy content of a bushel of corn is about 390,000 btu/bushel, and at $3/bu, this is $7.70 for one million btu's
Energy content of propane is 92,000btu/gal, and at a wholesale price of $1.10/gal, you are paying about $12/mmbtu

If you are trying to remove 10% of dry mass of moisture, you are removing 5.6lb per bushel. Heat of vaporisation is 970btu/lb, so call it 1000, so you need 5600 btu to remove 10% from a bushel, which will consume 1.4% of a bushel. Allowing for less than ideal efficiency, round up to 2% of the bushel, per 10% of moisture to be removed. Typically, corn is harvested at 25-50% moisture and needs to be at 15% for storage, so we'll assume 15% removal

So, if you had 1000ac yielding 150 bu, for 150,000 bu, and 15% moisture to be removed, you would need 3% of the corn, or 4500bu, costing $ 13.5k in lost revenue. With propane, if you can buy it for the $1.10, then you are spending about $21k, saving about$7k.

Not a lot in it for a harvest worth $450k!

Best way, would be to burn some of the corn stover - a little bit more work to set up, but it is "free", and has about the same energy content per lb as corn. Assuming that for every lb of corn, their is half a lb of stover, and we need 1.7 lbs of stover to dry a bushel of corn, then you are burning all of about 6% of the corn stover. And once you have the equipment set up, it's "free" from then on, and I'll bet you could probably rent it to some neighboring farmers too.

As for residential corn burning, best left to those who can get it wholesale. better still is to burn pellets made from corn stover, which is starting to become available. As a heating fuel, stover pellets sell for about $200/ton or $/bushel - more than the corn itself!

If that isn't an opportunity...

...and 15% moisture to be removed...

According to a Purdue paper, typical in the US Midwest seems to be reducing moisture from about 22% to 15%. Of course, it varies by location and year. That would take you from 3% of the corn stream down to 1.5% (in an average year).

As a heating fuel, stover pellets sell for about $200/ton or $/bushel - more than the corn itself!

Trying to handle stover that hasn't been at least partially processed to reduce its bulk seems like it would be difficult. Various papers say that the dry mass when corn is ready to harvest is about equally split between stover and grain. Also that stover has about twice the moisture content of the grain, so if the grain is at 22% moisture the stover will be at 44%. These numbers suggest (at least to me) that (a) you don't need very much of the stover and (b) you're going to have to dry the stover before it is suitable for use as fuel. Seems like it would be a lot simpler to divert a small amount of the dried corn into a hopper to feed the burner.

Not a lot in it for a harvest worth $450k!

But worth more if you can't get propane at all?


Numbers I had seen suggested "wet harvest" corn wast 28-30% moisture, but in any case the goal is 15%, so the heat input varies.

if you are just ineterested indrying the corn, I would agree that just burning some of the corn is the better way to go.

With the stover, processing that to make pellets is similar to processing grass, or even woodchips. yes, you will need to dry it - that may be possible in the field, to some extent, but not enough.
You harvest it using a silage type shredder, and then it has to be hammermilled before pelletising, and you can dry it at any of these stages, before pelletising.
My point is, that the stover represents a significant potential resource in itself. If you invest in the equipment to make the pellets, you can double the effective income per acre. And, you would likely have neighbouring farmers that you could buy stover from on the cheap.

The wood pellet operations can be profitable at a selling cost of less than $100/ton (and that includes collecting the wood waste from slash piles and transporting it), so a corn stover based operation would likely be even easier. You could also use the pellet equipment for making pellets from grass or wood waste - give the farmer something to do over the winter!

OFM, I want to go on record as emphatically agreeing. We have too little land to grow crops for food and fibers to turn that same land over to energy producing crops. My fear is that improvements in energy efficiency of corn growing will so raise the EROEI of corn ethanol that the demand for corn ethanol will skyrocket.

This article is quite positive in direction. I feel heartened to know that some agricultural researchers are asking good questions about what we can do to reduce fossil fuel inputs. This addresses reducing fossil fuel inputs through substitution of manure for commercial fertilizers, along with some concerns about labor input required. I'm sure that we will have plenty of labor available when the time arrives.


The yield per acre might stay the same, but the total production of corn and soybeans is reduced by 1/3 in the 3 year rotation and 1/2 in the 4 year rotation.
What would happen if we cut the corn/soybean production rates by 1/3 or 1/2 in the USA? It would be the end of biofuels! And - assuming the US Government would keep food stuffs here in the US during a shortage, there would be some very large areas of starvation in many other parts of the world.
If, as I believe, that farmers will begin planting enough oil seed (rape seed?) to produce all of the liquid fuels they need to run the farm right on the farm. Just like they used to use 1/2 of their acreage to grow hay and oats to feed the horse power before liquid fueled equipment became available, they will use 1/3 of their acreage to produce their own liquid fuels and continue to operate pretty much as before a fuel shortage/high prices. The shortage of corn/soybeans as farmers go to putting 1/3 of their farms to producing liquid fuels will cause the prices of corn/soybeans to rise to a level where the farmers will be making as much or more than they are now. But, there will be a lot of people who starve to death as a result. But nothing will prevent those deaths from happening as oil depletion puts oil production significantly below demand.

According to the post, the four year rotation (the recommended one) is corn–soybean–small grain/alfalfa–alfalfa. So we would get less corn and soybeans relative to a corn-soybean two year rotation, and we would get more small grain (oats?) and alfalfa. It seems like we would have to cut back on biofuel, and probably would need to reduce the number of cattle. The ones we do have would need to eat more alfalfa, and less soybeans and corn.

This is really a guess, but someone would need to look at the implications from a change in crop point of view. Grain fed meat isn't particularly good for people, and we certainly don't need as much meat as we eat today, so there are changes that can be made.

Actually, the cattle need hay anyway, so the alfalfa cycle would have come from somewhere else. That 'somewhere else' could then start the same 4 year rotation, making the overall production of soybeans and corn across both sites unchanged.

if the farmer has cattle on his property, they will be eating the alfalfa directly, and they don't need to be fed as much, if any, corn, so there is a definite offset there. Also, cattle can graze through the corn and soybean stubble, getting the lost grain and any undergrowth plants, plus dropping some manure in the fields as they go. There are some benefits to a mixed farm that a cropping only operation can't capture.

Our food infrastructure does seem skewed to produce meat and dairy at the expense of more balanced fare.

It'll be like the old days, when folks who couldn't afford the butcher's prices raised chicken and rabbit at home for their meat. But I think its clear that our current system is neither sustainable nor ideal.

"corn–soybean–small grain/alfalfa–alfalfa."

Talk about back to the future. Back in the '60s when Dad was still farming, our rotation for a dairy farm was;

Corn, oats/clover-timothy. hay, pasture, which also made a four year rotation, and worked out nicely on a 160 acre homestead-act farm.

Corn has a big seed, so it works well in the relatively coarse seedbed of a plowed up pasture. Then the oats went in the next year, where is also served as a nurse crop for the clover-timothy blend. Next year, the clover and timothy was ready for hay, and after the last cutting, the cows were turned out in it, and they stayed in that 40 for another year, when it was time to plow again.

At the time alfalfa wouldn't grow that far north, so wasn't an option. The low boron didn't help either, but I'm not sure when they figured that one out.

You could put soybeans in the mix for a five year rotation pretty well too.

You and Jon Kuz etc raise some useful questions.
Horses were essentially an 'energy crop'. If the available 'photon-capture acreage' is devoted to energy uses, including on-farm horses or any other conversion into fuel, then the carbon product is not being incorporated into food for humans (off-farm) in the form of either staple crops or meat. (The use though of inedible straws, farm residues etc. for 'energy', is a possible viable option.)

For 'soil nutrients', perhaps it is best to look at import / export balances for cropping systems. For example, exported staple crops or total biomass will typically remove from the farm relatively large quantities of soil nutrients. On the other hand, some energy crops particularly if produced and used in situ on the farm, including methane or bio-oil, will not export much if any soil nutrients. If, in yet another case, the 'soil nutrient removal' from a farm is exclusively in the form of farm-fed meat, then the soil nutrient export is relatively small compared with the case of exported 'staple' food or fodder. (It has to be said that if we compare such a farm's output of meat with a potential crop of 'staple food', far fewer calories are going to be available from any given acreage. Of course, farming a range not suitable for crop growing is something else.)

I am very glad to see these kind of studies provided by competent USA research (thanks to James Giese et al). There is good quality knowledge to rely on and I am glad that I made just that point about USA agricultural research capability in my two-part Guest Post of March last year ("How might we be fed?" placed by you as Editor on The Oil Drum)

From which corner of the 17th century Scottish highland farming operation did you extract your claim that "they used to use 1/2 of their acreage" to fuel their horses?

I expect agriculture to use less and less fossil fuel even as the proportion of the total supply of fossil fuel consumed by agriculture increases. As the price of liquid fuel rises and as electricity production in grain growing regions increases, mostly from windmills, farm machinery will be adapted to electricity. Liquid bio-fuels will be uncommon and most likely will account for less work than human labour.

The world, with Greater Chindia in the lead, will view starvation as an impetus to population growth and will act rationally to ensure its eradication.

In addition to old and painfully ill people who use starvation because other forms of suicide are denied them, starvation will largely be consigned to colonies of doomers, who, like unwitting WW2 Japanese soldiers hiding in the Indonesian jungle, are holed up in the hills but out of ammo to hunt the remaining rodents.

The barbarians will always emerge from the hills ready to rape, rob, and pillage when this seems to be the most favorable course of action from thier pov.

If I personally happen to be holed up and out of every thing but ammo ,the nearest by dwellers in the flat lands had best be maintaining a very efficient gaurd!

Of course I'm too old, and too civilized, to go in for the raping, but I guess I could still do a respectable job of robbing and pillaging. ;)

Even if the farmers start growing rapeseed (canola) for biodiesel, you still get very useful (high protein) animal feed from the press cake, so nothing gets wasted here. Farm equipment can also be adapted to be co-fueled by ethanol, or methane, or even woodgas. However, if energy is being used for grain drying, the best short term option is to use biomass for that operation first. It would be easy to work out the acreage of trees needed to fuel the grain drying operation.

As for transport of products, keep in mind that with a mixed farm, the cattle walk to work, you don;t need to bring as much corn to them. When the most profitable farming becomes one that is less oil intensive, we will see it happen fairly quickly.

If there is less corn production etc, people will not starve to death, food, and particularly meat, will just become more expensive. But the white foods, grain, pasta, potatoes, rice etc are and will remain relatively cheap to produce, buy and store. Fresh and perishable stuff is what will get cut back, as it is far more energy intensive to produce, move and store.

About a third of current US corn crop goes to biofuels. About another 60% goes to animal feed. So, the amount of corn fed directly to people is less than 10%. In fact, most of this is in the form of high fructose corn syrup and corn starch and a medley of processed food products. Similar numbers exist for soybeans.

Therefore, we theoretically could cut out 1/3 to 1/2 of corn and soy production and still have plenty of staple foods if a much greater proportion of these would go directly to human consumption and not indirectly through animal feed. And since biofuel production is has no net energy gain, we would be fine eliminating it too.

Less animal feed is not a big deal if you bring animals back into rotation on the land. We would likely have less meat, but still be nutritionally fine, or even better off.

Great post. This scenario, for the next 30 years, is a lot more realistic than the ones discussed a few weeks ago of going back to animal labor or using all solar electric tractors.

The approaches described above are still BAU-lite, however, and require significant diesel inputs (herbicide pass, planting pass, at least one more herbicide pass, harvesting pass, drying, transport to silos, transport to wholesalers, transport to food processors, transport to wholesalers, transport to retailers. The last 4 can easily be several hundred to over 1000 miles each. Don't think of food miles as just warehouse to store.

This approach might last 5-10 years, or maybe a little bit more. What then? Shouldn't we be thinking of the long term instead of just the near term?

Fred Magyar got me thinking about this last week with his comment on Insect farming to produce fish feed. It eventually struck me that we should eliminate the middleman- er, middlefish. This is a link to a site called City Farmer News:

The article of interest is "Third Millennium Farming (3MF) – Insect Farming in Cities".

I would direct you to page 14 of the PDF (sorry, I don't know how to get images into my posts, and don't have time to learn today.) Figure 4.2 shows 4 pieces of information regarding the feedstock footprint for Cattle, chickens, and Crickets. The most important to my mind, is the Energy Conversion Index. For cattle, it's 4.1; for chickens, 16.5; crickets, 25.

To quote from the article: "All things being equal, the final results show that growing feedstock for beef cattle takes 4.5 times more space than for broiler chickens; and that growing feedstock for crickets takes 0.035 times as much space as broiler chickens." (it should be noted that they are using algae as a feedstock for the Crickets.) The paper also notes that the water requirements for insects are typically lower than for other livestock.


You are right about having to think about the long term as well.

I expect part of the problem is that it is hard to figure out what to do, if you really have to give up industrial farming as it is done today. Substituting smaller sized oil driven equipment doesn't seem to help all that much (at least based on my reading of some posts we have had recently). One still has the issue of keeping them repaired, and labor input is much higher.

At some point, it seems like the equipment will need to be locally made, and the fuel (or other energy used to power it) will need to be locally produced.

Nice post. I'm currently negotiating for land to start my first hobby farm, but very skeptical it will ever actually be efficient without conventional FF inputs.

1) Is the 91% increase in labor being accounted for anywhere as energy input? It seems to me that is a whole lot of energy. Is the energy cost of supporting 91% more people in agriculture really a net energy win for a decrease in direct fossil fuel inputs? That doesn't seem obvious to me. I would tend to think not.

2) There seemed to be both the suggestion that conventional farming is so prevalent because it produces greater financial returns AND that "overall returns from the land are similar to the conventional system." Did the study get specific on money? That seems more likely to drive changes (or not) than anything else?

3) Is there enough manure to go around? It seems sort of like my friends who use fast food joint grease to run diesels--impossible to scale. But I really have no idea.

Zanzibar, given that there are so many unemployed people today, who are still being consuming food, fuel, housing etc, moving them into productive agriculture is a net benefit.

Farming has concentrated the way it has because it is indeed more profitable that way, not necessarily more productive. Clearly, for many american farmers the best route to profitability was to reduce labour input and increase mechanisation. The decline of the family farm contributed to this, as the family contributed significant free labour, especially relating to animals that needed a small amount of daily care. As fuel and equipment gets more expensive and labour again becomes cheap, things will change.

Keep in mind the farmer's first priority is to maximise profit, not production. Maintaining overall production is the government's problem, and given that they ares till paying some farmers to set aside land and NOT grow things, there is room for improvement there.

As for manure, I would agree with your restaurant analogy. Other sources are sewage sludge, and sewage effluent, if your farm is close to a treatment plant. Ultimately, the best source of nitrogen is from legumes, of which alfalfa is one. A full year legume crop can usually add as much nitrogen to the soil as would be applied to a grain crop. Again, with cheap FF, it was simply cheaper to ditch the legumes and add more fertiliser, but that pendulum is starting to swing back.

For your small scale hobby farm you actually have the best chance to avoid FF inputs, because a lot of the tasks are small enough to be done by manual labour, and some can be replaced by electricity. When I was growing up on a small farm, one of the jobs for myself and my brother was to "drag" the pasture with steel mesh to break up the cowpats. For large farms this is called a pasture harrow, and is pulled behind a tractor. It does not need a lot of power, so can be done by horse or manpower (or even a quad motorcyle) Good exercise, and not soul destroying if you do not have too much area to cover. You can also set up a tractor to run on electricity;
This is ideal for a small farm, as you are frequently doing small jobs that only need the tractor for a few minutes, or less than an hour. On a broadacre farm, it's just not an option.

So, you can do you farming with minimal FF inputs - you just can;t do conventional, large scale crop farming, that's all.

"When I was growing up on a small farm, one of the jobs for myself and my brother was to "drag" the pasture with steel mesh to break up the cowpats."

Hi, Paul. I spent a lot of time (and fuel) dragging the pastures as well. Later, I took a 2 part Rotational Grazing course (University Of NC and UGA, NC State Argiculture Dept.) and they said studies showed that dragging the pastures had no effect on productivity over time. There was some evidence that it may actually reduce production of foriage. Seemed counter-intuitive to me. The consensus was that it just made the pastures look better. I'll see if I can dig out the materials.

It also occurs to me that one needs to be sure of the sources of the manure. Any contamination will be hard to remove once applied. One case:

Last summer (2008) reports began to emerge of deformed, distorted and dying vegetable crops in gardens and allotments. It soon became clear that the problem was widespread. It was finally identified as damage caused by the weedkiller aminopyralid. The source? Contaminated manure.

I have to wonder if other contaminants (medications, hormones, etc.) can be uptaken by food crops fertilized with manure derived from factory farms. Just a thought.

Don't get me wrong, I love manure. I just cleaned the coop and added a fresh batch to my special high N compost pile.

Thanks for the nice post, James!

We had some seriously mutated carrots last summer. I mean, not just multi-legged, but sort of exploded and inverted roots.. made me really wonder what happened to make them grow like that..

The meds given to horses are the worst and will last a couple years in composted horse manure, so avoid any fresh horse manure and compost for at least two years before using on any garden.

Unemployed persons moving into agriculture to reduce FF inputs would appear to be a great improvement. I just don't think it would be fair from a net energy standpoint to ignore the inputs human laborers consume anymore than it would be fair to ignore inputs horses used for labor consume.

On reflection it also seems much more complicated of an issue. If labor rates are never allowed to seek any sort of market value, we may still be paying these formerly unemployed agricultural laborers enough that it makes food prices rise. That would just transfer money from another sector of the economy and create unemployed there. Then your right back where you started and the worthwhileness of it, I imagine, would hinge on my original net energy question.

Bit of a tangent sorry. BTW I am going to TRY to avoid FF's on my hobby farm, I'm just skeptical.

"I'm currently negotiating for land to start my first hobby farm, but very skeptical it will ever actually be efficient without conventional FF inputs."

That depends; what are you intending on raising?

I don't have a tractor at my farm, though I occasionally hire someone locally.

Our garden employs raised beds (no gas tiller or tractor), which are fertilized by chicken and sheep droppings (those that do not fall in the field, that is).

I buy baled hay, so that is one FF input. However, I also stockpile a paddock in the fall, so that I can keep sheep on pasture into early January, lessening my hay requirements.

I buy some grain supplements for late gestation and early lactation, another FF input.

I harvest small amounts of grain (and trim up pasture weeds) with a scythe, thresh the grain, a byproduct of which is straw, which I use in the lambing pens, which is then used as additional garden mulch to reduce moisture loss, suppress weeds, and fertilize the raised bed.

I'm still uncertain what I'll be raising. Believe me, I read all of these posts with my notebook out:)

Dear All,

I apologize for being late to the discussion! Doing some other stuff this morning…and just signed in to the “The Oil Drum” to see that the post was up…(Thanks! Gail…I was hoping to spark a little bit of dialogue and it looks like that is happening!)

A little background for all: I am Director of Science Communications at the American Society of Agronomy and I thought that this recent research from our Agronomy Journal would be of interest to the readers here, so thanks for the opportunity to contribute.

I have asked the lead researcher, Matt Liebman, or his colleagues at Iowa State to join in if they get a chance. Matt would be in a position to give some much more informed answers to any questions. Also, the original paper has been posted online early (non-subscribers should be able to view the abstract here: )and will be published in May issue of Agronomy Journal .

That being said, here is my take on some of the questions, and I hope Matt has time to comment on some:

Stewart: The soil fertility treatments ranged from no added nutrients, to composed manure, to combinations of added nutrients and manure.

The grain drying factor was interesting…look at some of the issues growers in the Midwest had this year on getting crops in so late…that energy input was a major factor and was weather dependent.

Yes, the cover crops you mention played a role as a “green manure.”

Hey StClair: Yep…we just moved from our long-time Segoe Rd. location to one over by PD and Fish Hatch Rd. The new building is nice…but I kind of miss the old 1960s building. By the way…isn’t Madison beautiful in the spring time! I have almost forgotten the snow…almost.

Gail: Your and other’s point is well taken: What does this do to overall crop production, if every grower switches to a three or four rotation? Is that the point…? I think some of Matt’s long term studies are looking at long-term productivity. My question: what is the trade-off for sustainability? Is that what we are talking about?

All, thanks for the chance to share some of the information from our member researchers. Also, I know that Matt and his colleagues are continuing to work on this.


James Giese
Director of Science Communications
American Society of Agronomy
Crop Science Society of America
Soil Science Society of America
5585 Guilford Road
Madison, WI 53711 * *

Hi James,

Thanks for sharing in this discussion with data from the upcoming publication in the Agronomy Journal.

I too frequented and preferred the older buildings on the Madison campus from 1980 to 1984 working on a Biochem undergrad degree. It is a beautiful campus and nothing could beat a bright sunny day in late March or early April after the lake had thawed, but the ground was covered with a fresh (and melting!) late snow. I truthfully still wake up occasionally from dreams that are staged on that campus.

Currently my wife live outside of Moorhead, MN. We hobby farm, but sell nothing at this point. [Day jobs that pay the bills are in Ag research laboratories near North Dakota State University.] It is simply interesting to see how much one can produce on a certain amount of land and with a certain amount of human versus fuel labor. As interesting has been helping an old friend who lives in downtown Minneapolis get into gardening for himself....walking him through his desires and needs for the garden, educating him on what to plant when, and seeing how it compares in relative yield to our own garden as well as his "satisfaction" quotient with this increased labor in his life. Like many I've seen, he's become quite hooked on the whole process...the opposite of the "drudgery" outlook.

With regards to rotations, when I worked on sugarbeet-soybean-wheat rotations up here there were of course those who kept trying wheat-on-wheat and tightening up to a sugarbeet-wheat-sugarbeet since beets are such good cash. Invariably, such scenarios came with bad disease problems, but they could squeak by due to the fertility of the Red River Valley soil. Sugarbeet production is high cash enough to afford fungicides for disease control, but fungicide rotation is required to prevent the build-up of fungicide resistance in the fungal this increases costs and time in disease monitoring.

The grain drying is quite a conundrum to me, since local farmers were harvesting corn here in March (planted last May) as the flood waters receded from their fields. Somehow the quality and price of what they were harvesting and drying (grain driers were operating around us after the harvest) must have justified the fuel spent and wear on the equipment. We have great photos of combines churning through mud, snow drifts, and water holes as they pull corn off the fields.

Interesting general discussion, but I must admit some disinterest in productivity per se, since so much of this focus seems to be geared toward insuring the divide between urban and rural.

When are Matt or one of the other researchers going to comment?

We all know there are fewer farmers all the time, we also know there are fewer full-time farmers all the time. Farmers, just like everyone else, want big HDTVs and bass boats, so many have a "real" job in town (or 2 or 3) and also like the rest of us, they owe that paycheck plus the harvest to the bank.

It's all well and good to think they can just drop alfalfa into the rotation, but they not only need a market for the hay but also the time and fuel and supplies to put it up 3 times a year - unlike grain, which goes in and comes out - I don't know how high fertilizer would need to get to make that pay.

That is unless they are going to just drop 1/3 of their farm income and plow the alfalfa down. It might be that fertilizer and fuel are that expensive but I don't know a lot of people who can lose that large a chunk of their income and stay whole.

And if fuel and fert are indeed that expensive you can bet town jobs will be getting harder and harder to come by...

You bring the animals to the alfalfa. It needs a little managing, to prevent bloating, but otherwise, they do a fine job on the alfalfa.

My brother, on his farm in Australia, undersows alfalfa (that "lucerne" in Australian farming) in the last year of his crop rotation (usually wheat or triticale). It saves a separate seeding pass the following year, and it grows slowly under the wheat over the winter, and after the harvest (which is actually late spring/early summer in Australia), the alfalfa will then grow on through the summer, its peak production period. The wheat stubble minimises wind and sun evaporation loss of moisture, and is also a good disease break. It leads to increased earthworm activity, and better soil structure, with improved moisture holding ability.

Farmers who continually do grain crops see a deterioration in soil structure and moisture capacity, especially if they don't use minimum till methods. The continual addition of nitrogen fertilisers gradually acidifies the soil, eventually requiring the addition of lime to correct it.

The alfalfa and cattle also diversifies his farm. By having the alfalfa and cattle, he is not totally dependent on the success of the grain harvest. If grain prices are down, or a wet harvest, it is unlikely that cattle prices are equally down - in fact they usually go up as people hold their cattle to eat the wet grain, so less goes to market.

A diversified farm is a less risky farm, and usually less energy intensive, minimising another risk.

Thanks Paul for bringing that up. Undersowing is another piece of the rotation, my grandfather would plant alfalfa and oats, and harvest the oats in 70 or so days. I believe through the 40s he had a 5 crop rotation where one crop was "fallow". This is something that has not been discussed here, allowing a field to lay fallow for a year. I'm very interested in low energy inputs to my farms in the US and Africa as well as staying away from pesticides and roundup. In africa we are experimenting with jatropha for our tractors, here in PA i'm thinking of pressed soybeans for dual fuel tractors. Lastly, my grandfather's dairy farm had free range cows, I'd like to see a plan that encompassed all of the above with chicken tractors in the field, not spreading cow manure.

Schoff, in Africa, or at least the southern part, the dung beetles will do that job on the cowpats for you. It is really on worth doing if you have a high stocking rate of cows. WE would keep them all in one field for couple of weeks, so they would eat it down (including the weeds), and then move them to the next. When we did so, we would then run around with our "pasture harrow", but this was fairly well grassed, productive land. A dairy farm would be even more so. Anything less, and I wouldn't bother with spreading

You have to be careful in laying fields fallow. You don;t want bare soil exposed to sun and wind, or you can lose it in a rainstorm or windstorm. Crop farmers in Australia use a fallow primarily to build up soil moisture for the following year, and leave the stubble from the previous crop to protect against sun and wind. But if that crop had any disease, you are better off burning the stubble.

It's amazing to think that productive farming happened before machinery and herbicides, but it did, it was just more labour intensive, less productive and more sustainable!

There is no doubt in my mind, that the "mix' of crops is a good thing, especially for low energy/low impact farming. choose the right pairings, and they complement each other.
if you are growing your own fuel, I would seriously suggest looking at co-fueling the tractors with woodgas - I would only burn edible fuel as a last resort.

You people missed my whole point about the farmer having bills to pay for a system built on current methods, which is one of the problems with threads about what everyone else should do.

I have a small farm and I raise cattle on grass and I have some calves strip grazing alfalfa this morning and I'll hand drill some corn into it to feed to a couple pigs and some chickens in a week or two. But big farming is nothing like that and as I mentioned, just like everything else, lots of it is mortgaged to the hilt and needs every bit of cash flow and operator attention it can get.

It's easy to pontificate about the 'right' way to do things in perfect world but don't expect farmers to quickly adopt methods requiring more labor and yielding less cash flow any more than you would willingly give up 1/3 of your income and work more hours to boot - especially not when corn is still trading at $3.50+.

Another perspective would be that high oil prices drives up food costs, and farmers will look for ways to reduce the number of passes they make. One year out of four of alfalfa in a field rotation will help feed those cattle as you are doing now anyway. When the oil crunch hits and really settles in, 70-90% of the population will find themselves strapped to pay their bills, so day job farmers will be no different, except they will have far more options.

You're right, Will but fewer passes is why RR corn became so widespread so fast. Today (ideally) you plant/fertilize, spray and harvest, you can't really get fewer passes than that.

I've seen the studies showing RR over conventional doesn't really improve harvests and some that it doesn't improve profit that much either but what it does do is get the farmer off the tractor to do something else. For the TOD crowd it's like me suggesting engineers go back to using slide rules because computers use too many resources.

The other thing is that on lots of farms in the corn belt - and any other row crop region for that matter, fences and handling facilities have been pulled out to make way for planting ditch to ditch - there just isn't a diversified farming infrastructure anymore.

I'm not saying things won't change, they definitely will, but it won't be as simple and bloodless as adding a forage crop to the rotation.

Sheep don't bloat on legumes, so what some livestock people do is run sheep in a field first. They eat most of the legumes, then the cattle come in and get the tall grass. You can do this with a green manure crop that includes legumes and small grains to reduce cattle bloat risk.

You are right that this takes more coordination and labor, but it does add value to the land. Farmers are all over the map in terms of openness, curiosity, interest in partnering with others, and economic incentive to change.

This article reinforces my suspicion that peak oil is not going to lead to mass starvation, at least not in North America. If "conventional" farming becomes unsustainable, we can find alternatives. Economic dislocation, genuine hardship and lots of whining from privileged Americans, yes. Shooting your neighbor for the last bag of cheetos, probably not.

1st time on Oil Drum, I noticed nobody mentioned explicitly no-till methods. Permaculture methods would eliminate much mechanization. Let nature do what it does best. In addition, alternating every four rows or so, why not use a plant/tree that drops its nutrients right in place to revitalize the soil where edible crops are produced? Depending on your elevation and longitude, managing natural water resources would also reduce reliance on mechanized handling. Every area has its invariable weather, however using the rainy season to capture your water for the year seems like a common over-looked method. Elsewhere in the world, the flooding of river banks would be welcomed. Why is it in America is it considered an environmental disaster worthy of relief? Random rants. Great post.

Welcome, goos!
Permaculture (as well as other forms of "sustainable" agriculture) are often discussed here. We get many posts and links from proponents, as well as replies from those that will posit that agriculture is inherently "unsustainable" by it's nature. As with most subjects on TOD, there is rarely a consensus achieved, but plenty of great discussions and points of view. Stick around!

Thank you for the introduction Ghung. Looking forward to learning more.

Welcome goostaf,

"I noticed nobody mentioned explicitly no-till methods."

Take a look at the very first comment and the link at the bottom of it.

Thanks, I missed that.

At present we get a lot of our calories from what I'd call 'military' farming whereby we assault the soil with giant machines, nasty chemicals and transport inputs and outputs over vast distances. That particularly applies to broadacre farming like cereal cropping rotated with animal grazing such as the ubiquitous wheat/sheep farms of Australia.

In contrast I note vegetable growers use machines with 10% of the power, they mechanically weed furrow beds rather than spray chemical, they use green manure not so much synthetic N. In an urban setting they could conceivably use methane fuel in the tractors and sewage sludge on the soil. The crop will need less washing, drying, freezing and transport. I suggest a new metric of farm productivity like (energy value of fossil inputs - calorific value of food). I believe the current loss is about 90% perhaps we could improve that. Thus -75% is 'better' than -90%.

Urban farming will require hard headed planning. I wonder when urban farms go ahead for Detroit then developers will want adjoining areas rezoned for building. Urban farmland must be protected from development and property taxes.

The US is one of the few countries that has enough land to afford fallowing to clover, alfalfa or other non cash crop legume. Asian countries are applying nitrogen at diminished yield/N because they need the yield.

A highly recommended book on the subject by Vaclav Smil:

Enriching the Earth: Fritz Haber, Carl Bosch, and the Transformation of World Food Production

Is anyone aware of any large scale tests on the addition of charcoal to soil (biochar, terra preta)? Smaller scale studies show numerous advantages in nutrient retention, biological activity, etc.

How about this;,%2021...

It gives lots of references to all sorts of things.

There is also this place;

but given that they exist to promote biochar, you have to be aware you may only be getting one side of the story.

I have personally seen some very large scale areas of charcoal (after bushfires in Australia) and I can definitively say that the regrowth is amazing, though this is not necessarily due to the charcoal itself. There is some anecdotal evidence though, that forest areas that get regular "cold" fires (that burn to charcoal and not ash) are more productive, as long as the plants are adpated to fire.

I don;t know of any broadacre farmers that use it, though I think it would be a very interesting crop trial. It would likely take a few years after charcoal addition to get the full benefits of the microbial activity, but the moisture retention would improve immediately.

Thanks, Paul

It occurs to me that using our biomass this way may be a more productive use than turning it into fuel. It also provides some level of medium/long term carbon storage. I need to substantiate some claims here:

Increased Nutrient and Water Retention— Biochar outshines all other organic soil material in its ability to attract and retain water and nutrients, as well as hold phosphorous and agrochemicals.2 Plants are healthier and less fertilizer runs off into surface water and leaches into groundwater.

Persistence— Biochar is relatively inert and therefore, persists in soil far longer than any other organic soil additives. Because biochar lasts 100s to 1000s of years, its benefits of nutrient and water retention and overall soil porosity keep working, unlike common fertilizers and conditioners.

Less Fertilizer Needed— When added to soil, biochar improves plant growth and crop yields while reducing the total fertilizer required. Nitrous oxide (NO2), a greenhouse gas, released from certain fertilizers is 310 times more potent than CO2. Biochar-conditioned soils reduce NO2 off-gassing by 50-80%.

(emphasis mine)

I've been toying with this idea for some time. This may be a good business/cottage industry, produced locally.

These guys have a small commercial scale mobile setup that can be moved to different areas, cleaning up biowaste, kind of a "Johnny Biochar" system. I wonder how much agricultural productivity would increase if charcoal application became as universal as the use of fertilizers.


There is some truth to support these claims;
1. Charcoal is extremely moisture absorbent, like a stiff sponge, it will hold about 5x its own weight of water
2.It does indeed hang around for millennia - nothing really eats it, and chemical degradation only occurs under certain conditions (e.g. fire). Charcoal has been found in peat bogs thousands of years old.
3. It is very chemically absorbent, that is why it is such a good filter media for pollutants. It has been used for low temperature NOx removal from exhaust streams, so it could do this in the soil, though I'd want to see some specific evidence of that.

Charcoal is a great cottage industry. As any BBQ devotee will tell you (being Australian, I am one) there is no comparison between lump and briquette charcoal - cooking over charcoal is the best method of cooking ever invented, and probably the first!
here is a wonderfully simple way to make it at home;

If you are going into the charcoal business, you should set yourself up to recover the methanol - you will get from 1 to 4% methanol by weight.

There is a good description about woodgas and methanol and the like here;

more info here;

As for industrial charcoal production, you think those mantria guys had just discovered charcoal! Their plant looks very expensive, and it's in one place. Unless you have a stable local supply (e.g. a sawmill) you will have to go further and further afield for your feedstock.

I think a better approach is to take the equipment to the wood, like this guy;

That way, you only transport the finished product, 1/3 the weight, and you can store it indefinitely!

If you can make real, local lump charcoal, you will be able to sell it at every gas stn, hardware store, food store in your area. Once the bbq aficionados discover it, they will buy it. Many restaurants that have wood fired ovens, would probably use it in preference to wood - it is much easier and less smoke! If you are using it for soil amendment, then you want to crush it first, but don't grind it - you want small sizing, but not to destroy the porous structure

Best "charcoal" I ever made was from a cut up old oak whiskey barrel. Cut the staves into bits about 2-3" long, and mix 50/50 with lump charcoal, and then bbq. The whisky flavour comes out into the food like you wouldn't believe (whisky, Scotch, to be precise, is the best marinate ever for steak)

if you are going to go into it commercially, the way to go would be to get one of these for small stuff

or a Laimet chunker, if you are doing logs, though you need a tractor to power it..

Can you tell what business I want to get into...

Now, time for a VB and to put some prawns on the (charcoal) barbie!



I reviewed this work last week on my own blog:

Includes some of the great graphics I found from posters these researchers have put together.

Great topic, thanks!


Good graphics indeed! While harder to measure, I would expect that soil quality and fertility is much better under the four crop rotation.
For that rotation, since there is less mechanical input, it also opens up the option for the farmer having less or smaller machinery. Assuming the farm was divided into four sections you are only growing half the corn and soybeans in any year that you used to. You could use smaller equipment, or make more use of contractors, share equipment with a neighbour, etc. The farm is also less vulnerable to weather events. something that might drastically reduce the corn harvest is unlikely to effect everything else the same way - you spread your risk.

It's funny to think that we are just re-learning what was learned centuries ago - a four crop rotation is better! We cheated nature for a few decades with fertiliser and herbicides, but eventually, Nature wins out, as she always does.

As a historical sidebar, changes in crop rotation have marked important turning points in history. The change from two crop to three crop (three field) rotation in the 8th c. improved nutrition by including protein and complimentary essential amino acid cntaining legumes in the diet. Three field system also allowed more land to be under cultivation and staggered the time of plowing, which was important because iron tipped plows were shared or rented / contracted as a plowing service, and there was less peak demand on draught animals. This according to Medieval historian Lynn White:

Also according to White, three field cropping allowed growing oats to feed horses, which grew in number in northern Europe because of feudalism. Horses were 50% faster at plowing, and also allowed people to congregate in villages and commute to their fields. Village life also made education of children possible. There are places the abandoned rural settlements can still be seen.

The British agricultural revolution of the 16th-18th c. would use a four crop rotation and marked another important turning point.

In addition to biochar, why not reroute the municipal waste generated from cities back to agricultural land? Instead of sewage being released into rivers and lakes, cities could retool their sewage treatment plant to return the nutrients back to the fields. Mining of fertilizers would be unnecessary.
I'll warn you ahead of time, I have some questions.
- Do no-till methods still need some form of large mechanization?
- Would the return to substantial shelterbelt farming revive the natural desire of birds and other animals to control the insects in aligning fields, rendering pesticides unnecessary?
- In places where Cacao is grown, there are a number of plants/trees that are planted to shade and provide nutrients to the producing cacao plant. I have seen this done with many other crops like corn and bananas. Would a similar plan work for American fields and crops, eliminating the need for rotations?
- Last one, are Arkansas and Texas the only rice-producing states in the U.S.? Why is there not more rice grown in the U.S. given our long history with Asian-Americans involved in infrastructure?
This discussion seems like a good place to drop these bombs.

I believe that one of the reasons that municipal treated sewage is not consisdered fit for fertilizer is the massive amounts of pharmaceutical poisons and hormones contained within it. This is especcailly true of western countries who gobble down pills for every little thing that ails them. It just may not be safe to put this stuff directly back on to food producing crops (or anywhere else for that mattter). Recycling treated water back into the drinking water has teh same problems and teh more times it cycles through, the higher the concentrations of pharmceuticals become. Removing all this stuff from treated sewage may be too expensive compared to the benefits.

This, unfortunately, is true, where food crops are concerned, but it makes excellent water/fertiliser for biofuel crops!

There is a new electrolysis based treatment (trial just done in my town) that has the unique feature of removing all the hormones/pharmaceuticals from the water, and taking them out in the sludge, which can then be dewatered and burned in a high temp furnace (e.g. pulp mill, cement kiln, etc).

Will take a while to scale up, but it looks promising, especially for towns/cities inland, where there is the best potential for water re-use.

If the concern is so great about pharmaceuticals in the water supply for food, why is there little concern about high levels of Atrazine in drinking water supply? I am sure the effects are comparable, after all, all man-made chemicals are all-pervasive. The oldest of man-made chemicals find themselves lodged in the fat of top predators or in the ice caps. A beached blue whale near San Diego was found to contain an insane amount of actual trash. How can we escape contamination of our food supply when we are producing future contaminants by the tons every day?

Some random thoughts on this fascinating subject:

On solar drying, and grain handling in general, the following paper comes frum the 1980's when we had our prior bout with high energy prices and fear of immediate shortages. Like so much promising research from that period, it was mostly abandoned when energy prices collapsed in the mid 1980's:

Likewise so many projects involving contour farming, hedge rows and tree blocks to provide wind protection, crop rotation, and on and on. When I was a child I was fascinated by such ideas as put forth in the encyclopia I had under the heading of "soil conservation", "water conservation". This was in the late 1960's when memories were still fresh of the dust bowl days of the 1930's. Again, many of these ideas were pretty much abandoned as farms became more industrialized, and immediate costs became the big concern for giant agribusiness.

I will not go into my fondness for methane recapture from agricultural waste, because there has already been so much done on this issue, but needless to say, recaptured methane could be huge in providing agricultural energy production.

Some have discussed electric farm equipment. Right now this does not seem to be cost effective, but advances on batteries and renewable energy production (wind, solar, geothermal) are moving very fast, so much so that using current cost to benefit calculations is pointless when looking more than 3 to 5 year out.

Once the premise of electic farm vehicles becomes viable, we then face a startling new potential advance (and I know this will not be popular to talk about on TOD but it is a reality that must be addressed:

Robotic agriculture.
Many agricultural tasks are predictable,repetitive, and confined to a well defined geographic area. If robots will not work on the farm they will not work anywhere. Electric propulsion, precise GPS guidence systems and advances in computer control technology is a convergence of technology that cannot be held back for long, If,and this is the big IF, the economics can be worked out. The technology is already being developed, but due to cheap fossil fuel the incentive for research in this area has not existed. Some primitive attempts are bing made:

Even without full robotics, advanced sensing devices are already able to bring down applications of fertilizer and pesticide, and this technology is still used in only a small percent of farms. This is a case where advances in one area of technology (computers, microchips and GPS) can mean radical changes in a completely non-related industry (agriculture).

Again, the attempts at robotic agriculture may seem primitive:

(there is a sentence in the above article, "GPS has long been used in various aspects of farm operation." If you are more than 40 years old, that one sentence should blow your mind.)

One of the most advanced firms in this area is Lely:

One of the most fascinating aspects of the robotic farm would be a question of scale: Will it make more sense to have a few very large renewable energy powered vehicles working in the farm, or would it make more sense to manufacture "micro-robots" by the tens of thousands as small as 2 inches or less, and bring them into the farm by the truckload? This is a revolution in the making, and no one can easily foresee the astonishing directions it will take.

There are other fascinating possibilities: It is not impossible to foresee more food grown at or very close to the store, or even in the store. The farmers markets and co-ops are well known for this, but it has never been attempted in chain type mass merchendising stores. Why? The biggest issue is labor. If you take out the unneeded packaging used in many grocery items, and concentrate only on the food itself, it does not take up that much area to retail a sizable amount of food per square foot. The nation is already full of big box stores sitting empty. If appropriate scale robots, perhaps powered by rooftop solar or onboard solar are used the labor problem becomes a non problem. Again, these may be robots no more than seveal inches or a foot in size, networked and controled by central computer control.

In 1980 Alvin Toffler wrote in his masterpiece book (a book that discussed every single issue I have ever seen discussed on TOD, and much more)Toffler made the astonishing prediction that "value added agriculture" may well be one of the great growth industries of the future. What did he mean by value added?

We are familiar with "value added" in other industries: This is the design of objects, technologies or services so that extra value is achieved by the "information added" aspect of the item. A Porsche is an example: The vehicle actually is manufactured using less material and labor than many much cheaper vehicles, but the price is considerably higher because the added design, the added engineering, the added "intelligence" put into the product contributes to its value. This is a fascinating breakthrough in thinking, becuase we can see value added by the not easily tangible aspect of information or design.

But how does one create "value added" agriculture? A carrot is a carrot, a stalk of corn or wheat is a stalk of corn or wheat. We now know that this is not true.

If the plant has been treated with unsafe chemicals, if the product comes from unseen and unknown sources and may not be clean, nutrient rich and healthy, if the plant consumed excess amounts of energy, pesticide or fertilizer to produce, then it's value is not as great, not as "smart", not as "value added" as the opposite, which would be a "value added" smart plant or crop, that is to say clean, nutrient rich, safe and of known origin, and bred for nutrition and healthy consumption, NOT for ease of shipping and maximization of profits. This is "value added" agriculture in its essentials. We are already seeing it begin to grow as an industry. But if the needed amount of "value added" food is to be provided, we cannot easily dismiss the contribution of very advanced smart technology, what I have called here on TOD "elegant design".

We are at a unique place in history, a time when many of the worlds largest institutions are in the "information" and what can be called the "intelligence" industry, adding design, adding intelligence and thus adding value to what are now cheap and plentiful substances (such as silicon and carbon, (close behind hydrogen as some of the most common elements on earth and in the universe) which then revolutionize every industry and every area they touch.

It is easy to dismiss the power of ideas; They weigh nothing, they are invisible, they are cost free and benefit free until they are implemented. Yet for human beings, they are the one thing that has created everything we call culture, everything we call art, everything we call technology. Energy was common in the universe before humans had the first idea, and will still be common in the universe after humans have had their last idea. Humans are able to use any energy other than food (and to even that we attach aesthetic, cultural, status and social ideas) because of the power of ideas.

Like all humans, I sometimes gripe, I sometimes whine. I am often moody and opinionated and intellectually vain, and my interests and desires are scattered all over the place. I am not often enough grateful for this fabulous time to be alive on this earth. It is a brief enough time, but it is a good time, and I am grateful for the opportunity to experience so much due to the power of human ideas explored and implemented over 5000 years.


I've wondered whether Diamond has paid much attention to the benefits that we derive from the writings, the inventions and the example of the 'collapsed' civilizations that we look back on. We're not rebuilding from scratch and merely repeating the experiment. We still get to see Plato, Marc Anthony, Confucious and Hammurabi and Nebuchanezzar, to weigh into our cultural construct, our designs in no few ways start where they left off. Wheels do get reinvented, of course, but the point is, the history that informs us is richer than what they had to lean on.. as long as we have libraries.


Interesting thoughts, but I have to disagree with you about robotic farming. Adding even more complex electronics to the farming business, to reduce labour inputs even more, is a step in the wrong direction, IMO. It transfers labour to somewhere else, makes the farm even more reliant on outside equipment that cannot be repaired on site, can only be replaced. Look at the manufacturing chain with electronics, the farm will be dependent upon components made in China or the like. And, I would not want my farm operation dependent on "software".

The best asset a good farmer has is his experience and ingenuity, robots cannot replace that.

Now, as for electrification of equipment, I am all for that, and have seen concepts for electrification of tractors, but, like anything, there are limitations.

If you want a wireless (battery) tractor, you run into the same problems as a car. It is great for a utility tractor/front end loader and the like, but to replace a 300hp diesel engine for ploughing all day long, you just can't do it. NOw, I have seen a concept for an overhead electric pickup, similar to trolley buses, with the tractor to one side. You go down the row, and then turn around the end of the line, and go back on the other side. Have also seen a concept based on a centre pivot irrigator, the gantry as the wire and follows the tractor around in circles. These are interesting concepts, but it's a huge capital expense, and if you go to minimum till methods, is not worth it. Electric would only be worth it for really equipment intensive crops, possibly like potatoes, sugar beets, etc

But, the real direction needs to be minimising the energy inputs by changing the farming systems, where practical - that is hard part.

Dumb question:

1. I have a small garden growing Corn, Beans, Tomatoes, Cucumber, etc...

2. I have a couple of bird feeders in the back yard and a ton of birds. Feeders are about 30 feet from garden.

3. Grass under feeders grows awesome...for obvious reasons.

Soooo, maybe it would make sense to just move a feeder into the garden and take advantage of free fertilizer? I could put it in a corner and every week or so mix up the dirt under the feeder and spread it around the plants, just to keep them from crapping on the physical plants themselves. Seems like an easy way to take advantage of free fertilizer.

Better yet would be to put up a bat house - their droppings are the best fertilizer around, and the bats won't be out and about when you are. You might think in terms of putting a compost pile underneath, that would be a pretty good setup.

The birds you really want to have around your garden are insect-eaters rather than seed-eaters. Houses nearby for species like Purple Martins or Bluebirds will do you more good.

I didn't think of a bat house. We have a ton of bats but now they typically sleep somewhere in the forest surrounding the house - though one did get in my basement last year and flew around in circles for about 30 minutes until I finally netted him and got him out. I might investigate mounting one on a pole at the edge of the woods.

Last year our Bluebirds raised 10 young in the Bluebird house in our yard (two broods). The female is sitting on 5 eggs as of yesterday afternoon so we have plenty of Bluebirds. Our neighbors have swallows that live in their chimney during the summer. I don't think we have enough open space for Purple Martins, we have less than 1/2 acre of grass, the rest is old forest. We do have about 16 hummingbirds that show up every summer, they eat a lot of small bugs. Now if I could only find something that ate ticks...

This has been knotting my brow for some time.

How will Northern America feed itself if climate change kicks in.
What will happen to the Great Plains?
I learned that the biome is very sensitive to changes in rainfall and switches between forest, grassland and desert.
In other words it is an unreliable source of food.

I found this reference that assesses the future less hysterically than I.

Today I spoke to a new hair dresser in Esperance Western Australia. She is from Halifax,Nova Scotia.
I asked her about the Cod fisheries collapse.
She had never heard of it.
What on earth are you teaching the kids there?

Re. grain drying being the major energy consumer: Iowa has good wind energy availability and electric heat pump crop drying is an established technology which gives high quality, controlled drying and efficient use of energy. How does the seasonal availability of wind energy match the crop drying calender?

I believe the odds of bioscience taking the bacterial nitrogen producing properties of legumes which fertilize soil and inserting them into virtually every commercial crop over the next 20 years is 100% greatly reducing the need for nitrogen based fertilizers.

This will create other nutrient replacement problems in the future but nitrogen fertilizer wont be a problem.

The real constraints on foood production are on fresh water and the energy to move it around.

P.O.V., running this week on PBS: "Food Inc." A must watch. Spot on about our food system. One of my favorite quotes:

"I'm always struck by how successful we've been at hitting the bullseye of the wrong target."

Ghung, your right it is an excellent film. My favorite quote was when the commentator said "Americans like white meat, so chickens are bred to have larger breasts."

Well, that explains a lot of things, and not just about food! :-)

Whatever you do folks, do not miss the real shocker "Earth Days", an episode of "American Experience". Stunning piece of work, the TOD crowd will absolutely LOVE IT, I thought for a few minutes that maybe a secret TOD film making crew wrote and produced it! Don't let the title fool you like I almost did, it is more than just another boomer vanity piece, it is steller in it's reach and complexity, a masterpiece.