To overfarm means to use land so intensively for growing crops or raising animals that the soil becomes exhausted and damaged. When farmers overfarm their fields, they might plant the same crop year after year without giving the soil time to recover, or graze too many cattle on a pasture until the grass can't grow back.

Overfarming depletes nutrients from the soil, kills helpful microorganisms, and can lead to erosion, where wind and rain wash away the exposed topsoil. The Dust Bowl of the 1930s happened partly because farmers in the Great Plains overfarmed the land. They plowed up prairie grasses that had held the soil in place for thousands of years, then planted wheat continuously without rest periods. When drought struck, the damaged soil blew away in massive dust storms.

Good farmers practice crop rotation, changing what they plant each season so the soil stays healthy. They might plant corn one year, then soybeans the next, giving the earth a chance to rebuild its nutrients.