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.