Nitrogen, phosphate, and potash are essential nutrients for the
production of crops used for food, feed, fiber, and fuel. More than
54 percent of the nitrogen and 85 percent of potash supply was from
imports in 2011. Because domestic production capacity is
limited, any future increase in nitrogen and potash demands will
likely be met largely by imports. In contrast, the supply of
phosphate mainly depends on domestic production, with U.S.
suppliers providing more than 90 percent in domestic use. The U.S.
is the second largest producer of phosphate fertilizers in the
world (after China), exporting more than 41 percent of its
production to other countries in 2011.
While commercial fertilizers are the major source of applied
nutrients, animal manure and other organic materials also
contribute nutrients for crop use. If over applied, though,
nitrogen and phosphate can harm the environment (see Nitrogen in Agricultural
Systems: Implications for Conservation Policy, ERR-127,
Likewise, pesticides and other chemicals are widely used to
reduce pest yield losses and facilitate crop harvest; however,
pesticides can also harm humans, animals, and beneficial organisms.
In addition, because many pests travel between farms, resistance to
pesticides can evolve faster when farm-level applications are not
In addition to monitoring on-farm decisions regarding the use of
chemical inputs (described in the topic Crop and Livestock
Practices), ERS tracks and analyzes trends in the aggregate use
of chemical inputs, such as nutrients and pesticides, and their
prices. Examples include:
- ERS evaluates the influence of rising energy costs and crop
prices on fertilizer prices, nutrient supply, and consumption. ERS
examines factors influencing volatile fertilizer markets and
farmers' strategies to manage nutrient use under price
- ERS evaluates factors driving trends in the use and composition
of pesticides in the United States. Changing relative prices of
inputs, trends in the extent and location of crop production, use
of biotechnology, adoption of organic systems, pest invasions, and
climate change all contribute to changes in pesticide use.
ERS also analyzes the determinants of nutrient and pesticide use
and pest management practices in conventional and organic
production systems and the impacts of practices and policies on
economic efficiency. The Crop and Livestock
Practices topic includes chapters discussing farm-level
Nutrient, Pest, and Manure Management. The Organic
Agriculture topic provides information on non-chemical
pest management and organic farming system practices.