U.S. crop producers use a variety of practices to reduce yield losses to pests, such as scouting fields to determine whether and when pesticide applications might be required (see the topic on Crop & Livestock Practices). Genetically engineered (GE) insect-resistant and herbicide-tolerant crops are also available for conventional producers (see the topic on Biotechnology) for more information on the adoption of GE seeds). Producers of certified organic crops are much more reliant on production practices that bypass synthetic chemicals, such as crop rotation, adjustments to planting and harvesting dates, and the use of beneficial organisms. Many such methods are also widely practiced by conventional producers. Factors influencing cropping practice decisions, such as the availability of GE varieties, the profitability of adopting organic practices, and the cost effectiveness of precision agriculture technologies all influence the sector-wide use of herbicides, insecticides, fungicides, and other pesticides.
In 2007, roughly 877 million pounds of active ingredients were applied to U.S. cropland at a cost of roughly $7.9 billion. In comparison, in 1980, roughly 1.1 billion pounds of active ingredients were applied at a cost of roughly $7.1 billion (in inflation-adjusted dollars). During 1980-2007 the aggregate quantity of pesticides applied in the U.S. declined at an average rate of 0.6 percent per year, while inflation-adjusted expenditures increased 0.6 percent per year. The prices paid by agricultural producers for fuel, seed, fertilizer, and labor increased roughly twice as fast as the prices paid for pesticides during this period.
Herbicides and plant growth regulators accounted for an average 49 and 65 percent, respectively, of the total amount of pesticides applied and inflation-adjusted pesticide expenditures. During 1980-2007, real expenditures on these two inputs increased by only about 0.1 percent per year. Insecticides and miticides together accounted for an average 10 and 21 percent of the total amount of pesticides applied and inflation-adjusted pesticide expenditures, respectively. Real expenditures on insecticides and miticides increased by 1.1 percent per year over the nearly 3-decades examined. Fungicides, other conventional pesticides (e.g. nematicides, fumigants, rodenticides), and other chemicals (e.g. sulfur, petroleum oil, sulfuric acid), as a group, accounted for an average 40 and 14 percent of the total amount of pesticides applied and inflation-adjusted pesticide expenditures, respectively. Their inflation-adjusted expenditures increased the fastest among these three categories of pesticides (at 6.4 percent annually), but annual expenditures for this group were also most volatile.
Corn, cotton, fall potatoes, soybeans, and wheat accounted for nearly two-thirds of pesticide quantities applied (see The Changing Organization of U.S. Farming, EIB-88, December 2011). ERS research uses detailed ARMS data to examine pesticide use for these five crops more closely. Total pesticide use on corn, cotton, fall potatoes, soybeans and wheat was generally stable during 1982-2007, increasing in some years and declining in others, with an average annual decline of 0.2 percent. Herbicide and insecticide quantities applied declined 0.8 percent and 3.5 percent per year, while fungicide and other-chemical (e.g. desiccants, growth regulators, and vine killers) quantities increased 3.7 and 7.5 percent.
Several factors drove changes in the use of pesticides during this period, including the widespread adoption of GE crops, the expiration of the glyphosate patent in 2000, the availability of new compounds with lower application rates, boll-weevil eradication, and changes in pesticide prices, which increased slowly compared to the prices of other inputs like fertilizer.
Of the five crops examined, 53 percent of the pesticide total was applied to corn in 1982, followed by soybeans (28 percent), cotton (9.6 percent), fall potatoes (4.8 percent), and wheat (4.5 percent). Corn's share declined to 40 percent by 2007 while fall potatoes' share increased to 23 percent (because of large increases in the application of other chemicals, particularly vine killers such as sulfuric acid). Herbicides accounted for the largest share of pesticides applied throughout 1982-2007, while the other-chemicals category increased most in share. Corn accounted for the majority of herbicide and insecticide use until the early 1990s, after which cotton accounted for the majority of insecticide use due to boll-weevil eradication efforts. The majority of fungicides and other chemicals were applied to fall potatoes. - USDA ERS