碳素是构成植物体的主要元素,也是微生物生命代謝不可缺少的物质。碳素循环对土壤肥力和农业生产有重要作用。由于豆科作物能借助根瘤菌固定空气中氮素,因此碳素的多寡直接影响豆科作物的产量和肥田作用。在豆田中施用碳氮比寬的物质,如秸秆、谷糠等,可以調节碳素营养,能提高豆科作物产量。国外有些人試驗,証明施入秸秆对豆科作物有良好影响,幷可以提高根瘤菌的活性。目前我国在这方面的研究还不多。針对山西雁北、晋中地区土壤肥力不高 Carbon is the main element of the plant body, but also essential for microbial metabolism of life. Carbon cycle plays an important role in soil fertility and agricultural production. Because legumes can fix rhizobium nitrogen in the air, the amount of carbon directly affects the yield and fertilizer effect of leguminous crops. The use of carbon and nitrogen in the bean fields wider than the material, such as straw, bran, etc., can regulate carbon nutrition, can improve the yield of leguminous crops. Some people abroad experiment proved that the straw applied to the leguminous crops have a good effect, 幷 can improve the activity of rhizobia. At present, there are not many studies in this area in our country. For Shanxi Yanbei, Jinzhong soil fertility is not high