| 环境 |
crop rotation (An agricultural technique in which, season after season, each field is sown with crop plants in a regular rotation, each crop being repeated at intervals of several years. Crop rotation minimizes the risks of depleting the soil of particular nutrients. In rotation systems, a grain crop is often grown the first year, followed by a leafy-vegetable crop in the second year, and a pasture crop in the third. The last usually contains legumes; such plants can restore nitrogen to the soil. Notwithstanding, high yields tend to depend upon the continued addition of chemical fertilizers to the soil) |
