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, September 2011).
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 coordinated.
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 uncertainty.
- 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.