Nitrogen, phosphate, and potash are essential in the production of crops used for food, feed, fiber, and fuel. Applied annually, most of these nutrients are absorbed by the crop, but when applied in excess, they can be lost to the environment through volatilization into the air, leaching into ground water, emission from soil to air, and runoff into surface water. These losses can be reduced by adoption of best management practices (BMPs) that increase the nutrients' accessibility for plant use, enhance plants' ability to uptake nutrients, and more closely match nutrient applications with agronomic needs.

See the following ERS reports for more information:

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 the following ERS report for more information:

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.  See the following ERS report for more information:

In addition to monitoring on-farm decisions regarding the use of chemical inputs, ERS tracks and analyzes trends in U.S. aggregate use of chemical inputs 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 (see the ERS data product, Fertilizer Use and 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.