While economic data on crop values are strictly commercial/ agricultural summaries, they can be useful as surrogate indices of land use/ cover change, or in estimating food subsidies (e.g. waste grain) for wildlife. Posted by the US Department of Agriculture (USDA) Economics and Statistics System at Cornell University, the site contains the "annual marketing year average prices and value of production of principal crops". Principal crops include barley (all, feed, and malting), hay, oats, rye, wheat (all, winter, durum, and other spring), upland and American-pima cotton and cottonseed, corn, dry beans, flaxseed, peanuts, sorghum, soybeans, sunflowers, and rice. These data are provided by the National Agricultural Statistics Service (USDA).