Department of Agriculture research in the 1930s and '40s documented the importance of farming practices based on human skill and hand work - crop diversification and rotations, integration of animals, and using grass to guard against erosion, manage pests, and maintain soil fertility. But, as Berry notes, at mid-century the American approach to producing food veered sharply away from farming founded on human stewardship, natural cycling, and recycling. It abandoned grass and embraced chemicals and machines.

As World War II munitions plants were converted to manufacturing agricultural chemicals, U.S. use of manmade fertilizers quickly doubled. Government policy subsidized and encouraged maximum grain output, while discouraging permanent pastures, crop rotations and diversity, and grass buffers.

Berry notes that from 1950 to 1970 "farms became larger and more specialized, handling either crops or livestock instead of both," while chemicals and machinery skyrocketed. Artificial fertilizer use in those years, for instance, increased by nearly 300 percent.

These trends have persisted. Farming now uses four times more energy than in 1950, about 40 percent of which goes into producing fertilizers and pesticides. Some 20 million tons of chemical fertilizer and 1.1 billion pounds of herbicides, insecticides, and fungicides are used on U.S. farms every year. Diversity of farm crops has disappeared. While in 1900 U.S. farms averaged five different crops, farms today average just one. Genetic diversity on farms was reduced by 75 percent during the 20th century, according to a United Nations report.

All of this has taken a heavy environmental toll. Repeated application of agricultural chemicals renders soils brittle and lifeless, prone to blowing and washing away. Eighty percent of U.S. agricultural lands show severe to moderate erosion, which is occurring at a rate seventeen times faster than nature can re-generate soil. Groundwater, lakes, and streams are increasingly contaminated by pesticides, herbicides, and fertilizers.

Although automation and mechanization have reduced the difficult physical labor of food production, they have contributed to our national obesity epidemic, and rendered agriculture utterly dependent on such non-renewable, polluting substitutes for human labor. In today's specialized, segmented, and mechanized agriculture, chemicals are the answer to fertility, pest control, and weed suppression. The farmer's hands, knowledge, and husbandry have been replaced by machines, capital goods, pharmaceuticals, and fossil fuels, used directly to power farm equipment and indirectly to manufacture chemical fertilizers, pesticides, and herbicides.

Mechanization has reduced conventional animal farming to production and eliminated true animal husbandry. Laboratory-produced vitamin D and antibiotics now make it feasible to restrict animals to the indoors round the clock. Feed and water are delivered mechanically; manure removal systems are automated. Humans have ceased providing individual animals attention. As I noted in Righteous Porkchop, Department of Agriculture studies show that at a typical confinement facility, a pig is in the company of a human for 8 seconds of each day. Such an approach cannot provide appropriate care.