Factors influencing herbicide use in corn production in the North Central region

Chemical inputs have contributed to agricultural productivity and raised concerns about health and environmental risks. Identification of less chemical-intensive production practices is an important step toward reducing farm chemical use. Knowledge of the demand price elasticity for chemical inputs and the effect of participation in commodity programs is also needed for evaluating policy options. Herbicide use in U.S. corn production is examined in this study. In 1992, 250 million acres of U.S. cropland were planted with major field crops and various vegetable and fruit crops. These crop acres were treated with more than 480 million pounds of herbicides, insecticides, and fungicides, of which 388 million pounds (80 percent) were herbicides. Corn acreage alone received 224 million pounds of herbicides, accounting for 47 percent of the 480 million pounds of pesticides used. The demand for herbicides in corn production is analyzed using field-level data in 10 states for the period of 1990 to 1992. Per-acre herbicide quantities are regressed on herbicide price, expected corn price. commodity program participation, production practices (cropping sequences, tillage system, application timing and method. applicator, seeding rate, length of growing season, and cultivation), and weather variables (temperature and precipitation). The major findings are: (1) herbicide demand in corn production is inelastic with respect to both own and output prices; (2) commodity program participants used more herbicides than non-participants; (3) herbicide use can be greatly reduced by switching from broadcast to band applications; and (4) switching from conventional tillage with the moldboard plow to other tillage systems increases herbicide use, but switching from conventional tillage without the moldboard plow to conservation tillage does not always increase herbicide use.