Land and Natural Resources
U.S. agricultural production relies heavily on the Nation’s land, water, and other natural resources, and has a direct impact on the quality of the Nation’s natural environment. Over the years, significant improvement in the sector’s productive use of resources has reduced the amount of land and water needed per unit of output, and concerted public and private efforts have greatly improved the sector’s environmental performance. These charts document several aspects of these trends.
USDA conservation efforts rely mainly on voluntary incentive programs to address natural resource issues. The Conservation Reserve Program pays farmers to remove environmentally sensitive land from production and encourages partial field practices including grass waterways and riparian buffers. Working-land programs provide technical and financial assistance to farmers who install or maintain conservation practices on land in production (e.g., nutrient management, conservation tillage, and field-edge filter strips). Agricultural easements provide long-term protection for agricultural land and wetlands. The Regional Conservation Partners Program coordinates conservation program assistance with partners to solve problems on a regional or watershed scale.
Agriculture accounted for an estimated 10 percent of U.S. greenhouse gas (GHG) emissions in 2014. In agriculture, crop and livestock activities are important sources of nitrous oxide and methane emissions, notably from fertilizer application, enteric fermentation (a normal digestive process in animals that produces methane), and manure storage and management. GHG emissions from agriculture have increased by approximately 10 percent since 1990. During this time period, total U.S. GHG emissions increased approximately 7 percent.
The 2012 U.S. land area amounted to nearly 2.3 billion acres, with nearly 1.2 billion acres in agricultural use. The share of the land base in agricultural use declined from 63 percent in 1949 to 52 percent in 2012, the latest year for which comprehensive national data are available. Gradual declines have occurred in cropland, while grazed forestland has decreased more rapidly. In 2012, 392 million acres of agricultural land were in cropland (an 18-percent decline from 1949); 655 million acres were in grassland pasture and range (4 percent more than in 1949); 130 million acres were in grazed forestland (59 percent less than in 1949); and 8 million acres were in farmsteads and farm roads (45 percent less than in 1949). Urban land, while it represents a relatively small share of the U.S. land base, has nearly tripled in area since 1949.
The CRP covered about 24 million acres of environmentally sensitive land near the end of 2016, with an annual budget of roughly $2 billion (currently USDA’s largest conservation program in terms of spending). Enrollees receive annual rental and other incentive payments for taking eligible land out of production for 10 years or more. Program acreage tends to be concentrated on marginally productive cropland that is susceptible to erosion by wind or rainfall. A large share of CRP land is located in the Plains (from Texas to Montana), where rainfall is limited and much of the land is subject to potentially severe wind erosion. Smaller concentrations of CRP land are found in eastern Washington, southern Iowa, northern Missouri, and the Mississippi Delta.