Sustainable farming

I've heard the phrase 'sustainable farming' bandied about. What does it mean and do many farmers practice it?

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Sustainability has definitely been bandied about a lot lately, perhaps the best bet is to look up sustainable in the dictionary. Each farm is as individual in it's abilities and constraints as each farmer.

I think that totally sustainable farming would mean that farm inputs are quantitatively and qualitatively sufficient relative to farm production and to keep the soil in as good or better condition through successive generations of care. Disease and weed populations would have to be managed so that future years crops wouldn't have to deal with worsening conditions. Energy used would have to come from renewable sources either on the farm or from nearby to reduce transportation costs.

I'm willing to bet that there are no sustainable farmers anywhere on the planet. Soil is being depleted, fossil fuels are being thrown at the problems of soil nutrient deficiency and weed control. A shortage of farmers caused by increasing input costs and decreasing farm incomes means that the farmers left are trying to husband too much land, and are more and more out of touch with the individual parcels of land in their responsibility. At the same time I'm sure that we are all trying our best to ensure sustainability. Unfortunately, or maybe fortunately sustainable agriculture is the responsibility of society in general.

Sustainable agriculture refers to the ability of a farm to produce perpetually. Two key issues are 1) long-term effects of various practices on soil properties and processes essential for crop productivity, and 2) the long-term availability of inputs. Practices that can cause long-term damage to soil include excessive tillage (leading to erosion) and irrigation without adequate drainage (leading to accumulation of salt in the soil). Long-term experiments provide some of the best data on how various practices affect soil properties essential to sustainability.

While air and sunlight are generally available in most geographic locations, crops also depend on soil nutrients and the availability of water. When farmers grow and harvest crops, they remove some of these nutrients from the soil. Without replenishment, the land would suffer from nutrient depletion and be unusable for further farming. Sustainable agriculture depends on replenishing the soil while minimizing the use of non-renewable resources, such as natural gas (used in converting atmospheric nitrogen into synthetic fertilizer), or mineral ores (e.g., phosphate). Possible sources of nitrogen that would, in principle, be available indefinitely, include: 1) recycling crop waste and livestock or human manure, 2) growing legume crops and forages such as, peanuts, or alfalfa that form symbioses with nitrogen-fixing bacteria called rhizobia, 3) adapting the current industrial nitrogen fixation process to use hydrogen made by electrolysis (perhaps using electricity from solar cells or windmills) instead of natural gas, or 4) genetically engineering (non-legume) crops to form nitrogen-fixing symbioses or fix nitrogen without microbial symbionts. The last option was proposed in the 1970's, but would be well beyond the capability of current (2006) technology, even if various concerns about biotechnology were addressed. Sustainable options for replacing other nutrient inputs (phosphorus, potassium, etc.) are more limited.

In some areas, sufficient rainfall is available for crop growth, but many other areas require irrigation. For irrigation systems to be sustainable they must be managed properly (to avoid salt accumulation) and not use more water from their source than is naturally replenished, otherwise the water source becomes, in effect, a non-renewable resource. Improvements in water well drilling technology and the development of submersible pumps have made it possible for large crops to be regularly grown where reliance on rainfall alone previously made this level of success unpredictable. However, this progress has come at a price, in that in many areas where this has occurred, such as the Ogallala Aquifer, the water is being used at a greater rate than its rate of recharge.

According to Wikipedia anyway - http://en.wikipedia.org/wiki/Sustainable_agriculture

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That works for me. The only area that I would stress is that sustainable farms should be well enough appreciated by society, and I'm pretty sure there will come a day when this will occur, that farmers can stay on the land and train the next generation of farmers in the proper handling of the individual plots in his or her care.

This means that farmers receive enough for their produce that they don't have to work off the farm to support it or work away from the farm and just keep moving on.

[debs]

There's an interesting video here on sustainable farming.

http://youtube.com/watch?v=pW_ZU7X3wpE

High School students interview an organic farmer, a co-op manager and others about sustainable agriculture.

[hunter00]

well if you want to be informed of the other side of sustainable farming...
then you should avoid these unsustainable farming practices in
Agriculture Special Report : Unsustainable Farming Practices | AgriBusinessWeek

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Hi hunter00, all the advice looked interesting, I've never heard of leguminous trees before.

[UrbanFarmboy]

as defined by U.S. law.

Sustainable agriculture was addressed by Congress in the 1990 Farm Bill [Food, Agriculture, Conservation, and Trade Act of 1990 (FACTA), Public Law 101-624, Title XVI, Subtitle A, Section 1603 (Government Printing Office, Washington, DC, 1990) NAL Call # KF1692.A31 1990]. Under that law, “the term sustainable agriculture means an integrated system of plant and animal production practices having a site-specific application that will, over the long term:

* satisfy human food and fiber needs
* enhance environmental quality and the natural resource base upon which the agricultural economy depends
* make the most efficient use of nonrenewable resources and on-farm resources and integrate, where appropriate, natural biological cycles and controls
* sustain the economic viability of farm operations
* enhance the quality of life for farmers and society as a whole.”