Pesticide use in U.S. corn production: Does conservation tillage make a difference?

ABSTRACT: This study analyzed herbicide and insecticide application rate data collected in surveys of farmers in the Corn Belt to determine if significant differences existed between five tillage practices: conventional with moldboard plow, conventional without moldboard plow, mulch-till, no-till, and ridge-till. Survey data from 1990, 1993, and 1995 were analyzed, and results compared to similar studies reported in the literature for the years 1980, 1990, 1991, and 1992. Only with no-till and ridge-till was there a clear statistically significant difference in herbicide application rates between conventional and conservation tillage systems. With respect to insecticides, application rates with conservation tillage were found to be no higher than with conventional tillage, and often lower. The key variable that determined pesticide loadings in the study area was the number of acres treated in each tillage class, not differences in per hectare application rates between classes.