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Ecology and Agriculture: A Marriage That Must Be Made on Earth : Farming: When half Iowa's topsoil is lost in 150 years, reliance on man-made chemicals had better yield to nature's principles.

November 19, 1989|Donella H. Meadows | Donella H. Meadows is an adjunct professor of environmental and policy studies at Dartmouth College

PLAINFIELD, N.H. — Once it was the O-word--organic farming--an idea associated with kooks and branded by chemical companies as a sure route to starvation.

Now it goes by many names--sustainable agriculture, alternative agriculture, low-input, regenerative, ecological agriculture. To the surprise of nearly everyone, those are now buzzwords in Washington among the committees preparing the 1990 farm bill. We may be on our way toward kinder, gentler farming.

In September, the National Research Council concluded a four-year study of America's organic agriculture. In summary, Committee Chairman John Pesek of Iowa State University said: "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."

Agricultural and environmental experts assembled a month later in Salina, Kan., to celebrate what geneticist Wes Jackson, co-director of Salina's Land Institute and convener of the meeting, called the marriage--or maybe the engagement, or at least the courtship--of ecology and agriculture.

Prof. David Pimentel of the College of Agriculture at Cornell opened the ceremonies with a zinging testimony on why this marriage is badly needed. American agriculture may look successful, he said, but it can't last. Not economically, not environmentally. It is unsustainable.

Preventable soil erosion costs the nation $44 billion a year in fertilizers carried off fields, in decreased crop production and in eroded soil piling up behind dams, silting up canals and polluting waters. To put that number in perspective, the food and fiber sectors account for about $700 billion a year of the U.S. gross national product. Of that amount, roughly $30 billion is farmers' net income, which is supplemented with another $25 billion in government price supports.

Soil loss from erosion is, on average, 16 times the rate of soil formation. Half the topsoil in Iowa has disappeared in just 150 years of farming. About 100 million acres of U.S. cropland have been so severely degraded that they have been abandoned.

The only reason this soil loss has not yet shown up as enormous drops in yield is that farmers have been able to disguise it with purchased fertilizers made from fossil fuels. They are substituting oil for soil, a non-renewable resource for a renewable one, a practice that can last only as long as oil is cheap.

Between 1945 and 1975, the nation blacktopped an area of prime agricultural land the size of Ohio and Pennsylvania combined. As land has been lost to pavement, it has been gained from wetlands. Half the nation's wetlands have been drained for agricultural use, with an immeasurable loss in wildlife, ground water recharge and flood control.

The government spends $4 billion a year subsidizing irrigation, causing farmers to waste artificially cheap water. Irrigation districts are, on average, mining aquifers 25% faster than the ground waters are being recharged. In the Texas Gulf area, the overdraft is 77%.

Livestock in the United States eat 10 times more grain than the human population. Their manure contains five times more soil nutrients than farmers buy in fertilizer, but only a fifth of that nutrient is used effectively. The rest is a massive pollution problem.

Farmers spray a billion pounds of poison on the land each year to kill pests. They lose 37% of crops to pests, anyway. The loss rate is slowly increasing, though pesticide use is also increasing. Why? Because pesticides allow farmers--for awhile--to plant huge swaths of a single crop, a standing attraction to pests. Because pesticides wipe out pest-eating predators. Because 25% to 50% of air-sprayed pesticide doesn't hit the intended field, and 98% doesn't hit the pest. Because the more pesticides are used, the more pests evolve to become resistant to them.

One price we pay for the pesticide habit is 45,000 human poisonings a year. Those are only diagnosed and reported incidents of acute poisonings--not the cancers that may come years later. Another price is $1.2 billion for monitoring wells, inadequately, for pesticide residues. (The pesticides themselves cost $4.1 billion a year.) The cost of poisons working through ecosystems--affecting birds, fish and the microbial populations of soils--is uncountable.

Pimentel calculates that pesticide use in this country could be reduced by 50% with no decrease in yield, and with a food-price increase of only 0.6%.

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