Monoculture is the use of land for the cultivation of one type of crop at a time, usually for multiple years in a row. The scope of this definition may vary, but monoculture is associated with large-scale industrial agriculture and is at the landscape level, with one dominant crop over one farm, a farming region or even an entire country. Monoculture relies on economic efficiencies of scale in farm machinery or temporary farm labor but increases risk of pests and diseases, and greatly reduces soil health. Monoculture uses a small number of genetic variants, or cultivars, which makes economic sense for global seed companies, but results in poor ability to grow regionally adapted crops that are resilient to the effects of climate change. In the U.S., monoculture is most associated with commodity crops like corn, soy, cotton, and wheat.