Simply put, our food supply system is not sustainable. Professor David Pimentel of the College of Agriculture at Cornell University said in an October 1999 speech that American agriculture “may look successful, but it can’t last. Not economically, not environmentally. That has not changed significantly.
The federal government has found it necessary to subsidize large farms. This system takes more resources and produces more environmental damage than the earth can tolerate long-term. The reasons for this are many.
Americans consume a lot of red meat. This is not healthful, and not efficient. American agriculture has changed from many small, independent farms to fewer large corporate farms. Livestock is raised in feed lots, knee deep in mud and manure, and fed grains instead of their natural diet of grass. It is estimated that 9-16 pounds of grain are required under this system to produce 1 pound of beef.
Ruminant animals (cattle, sheep, goats, buffalo and camels) produce methane as part of their natural digestive process. The number of livestock animals has exploded from 8 billion in 1965 to 20 billion in 2010. In the United States, many of these animals are kept in CAFO’s, large feed lots. The manure they produce is dumped into “lagoons” to be broken down by anaerobic bacteria, thus releasing more methane. Livestock production contributes almost half of the increase in greenhouse gases we have seen in the last 100 years.
Over 100 million acres of American cropland erode each year. Our soil is disappearing at 16 times the rate of natural soil replenishment. Iowa has lost over half its agricultural soil to erosion. In this country, over 100 million acres of once prime farm land have become so depleted that they are now abandoned. To make up for the poor quality of soil, farmers use chemical fertilizers to make crops grow and pesticides to protect them.
Preventable soil erosion costs the United States $44 billion per year in eroded soil that piles up behind dams, silting of canals, polluting of water, fertilizer carried off from fields, and lower crop yields. As the soil is depleted, farmers use increasing amounts of fertilizer for decreasing crop yields.
Plant pests such as insects, weeds and disease are attracted to large areas of a single crop. To protect the plants, farmers spray a billion pounds of poison on their land each year at a cost of $4.1 billion. Still, they lose 37% of crops to pest infestation. The rate of loss is increasing, partly due to the development of resistance to the chemicals.
Agriculture is the greatest single source of water pollution, affecting half of our stream miles. Over 40% of our rivers and lakes are too polluted to allow fishing and swimming. The federal government subsidizes irrigation by $44 billion annually, causing farmers to overuse artificially cheap water. This in turn drains aquifers in irrigation districts 25% faster than groundwater recharge. In the Texas Gulf area, the aquifer depletion has reached a rate of 77% faster. Groundwater pollution costs us $1.2 billion per year in monitoring of wells for pesticide residue.
To make up for agricultural land that has been paved over, we have drained wetlands that used to be carbon sinks and habitat for wildlife, and that once contributed greatly to recharging of the groundwater supply. As climate change increases, the effects of these problems can also be expected to increase.
Another problem with large farms that produce a single crop is that monoculture results in more vulnerability to pests and plant diseases. Soil becomes compacted and depleted in part due to tillage practices, so chemical fertilizers are used to give the plants something on which to grow. Pesticides and fungicides are sprayed on crop plants, to the extent that many potato farmers will not eat their commercially grown product. Instead, they plant a small plot of potatoes for their families.
Almost 2/3 of the species on the endangered list are there due to the impact of agriculture. Loss of habitat and poisoning due to pesticides and chemical fertilizers take a tremendous toll on our wild creatures.
In contrast, organic farming is defined as “an ecological production management system that promotes and enhances biodiversity, biological cycles and soil biological activity. It is based on minimal use of off-farm inputs and on management practices that restore, maintain and enhance ecological harmony.” (National Organic Standards Board.)
Studies have shown that farms that follow organic practices experience higher yield and produce less pollution than so-called “conventional” farms. They steadily improve the soil, resulting in greater water retention and less run-off and erosion. Some 100,000 American farmers have proven that organic practices are efficient and can be used on large and small farms alike.
In September the National Research Council concluded a four-year study of America's organic agriculture. Committee Chairman John Pesek of Iowa State University said in summary: "Our committee is convinced that such methods do work, that they would produce an ample food supply if widely adopted, and that our nation's environmental problems and health concerns due to pesticide residues would be reduced. The potential benefits of alternative agriculture are too attractive to continue to lie fallow."
Organic farmers perform these miracles by using a modern approach which takes advantages of natural soil replenishment and biological cycling. Production costs are much lower, and output is comparable to so-called “conventional” farming. They plant a diverse mix of crops, use efficient nutrient cycling, establish beneficial habitats, rotate crops, and plant companion crops.
Livestock raised on organic farms contribute to the healthy management of soil. Research has shown that the manure of livestock animals contains 5 times more nutrient that the chemical fertilizers purchased by “conventional” farmers but only about 1/5 is used effectively. The rest ends up polluting our environment. Manure that is spread on fields or dried produces only a minimal amount of methane. If we simply returned to the age-honored cycles developed over thousands of years of agriculture, this vital resource could be returned to the soil.
Grazing livestock do not require the large amounts of grain consumed by animals confined to CAFO’s. They can also help with the control of weeds. For example, sheep can control leafy spurge, a pest weed prevalent in north central United States that is poisonous to cattle.
Healthy soil is a living resource. The microorganisms present in good soil keep plants healthier. Earthworms aerate and further nourish the soil. Organic farmers practice crop rotation. They use nitrogen-fixing legume forage that enriches the soil and provides food for the grazing animals. They practice conservation tillage, which further protects the soil. Organically treated soils contain a wide range of nutrients not available in chemical fertilizers.
As the climate changes, we will need the biodiversity that organic farmers practice to avoid food shortages caused by widespread crop failure in monoculture. We will need to introduce plant species that are adapted to the changing temperature and precipitation patterns. We also need the organic practices that have sustained human and animal populations for thousands of years.
References and further information:
http://atra.ncat.org/atra-pub/organiccrop.html
http://www.sustainer.org/dhm_archive/index.php?/disp lay_articles=agricultured
http://www.ers.usda.gov/publications/aer740/AER740b. PDF
ftp://ftp.fao.org/docrep/fao/009/j927e/i0271e.pdf
http://www.sustainableagriculture.net
Anna Lappé, Diet for a Hot Planet, 2010, Bloomsbury USA, New York