免耕与覆盖对土壤微生物数量及组成的影响

Effects of no-tillage and mulch on soil microbial quantity and composition

研究了连续2年春小麦-豌豆轮作后6种不同处理土壤微生物的数量与组成,结果表明:与传统翻耕比较,免耕可使土壤微生物数量增加,春小麦-豌豆轮作序列增加了14.9%,豌豆-春小麦序列增加了38.4%,但对土壤微生物组成没有明显改变;覆盖可使土壤微生物数量增加,春小麦-豌豆序列覆膜增加较多,增加了30.9%。豌豆-春小麦序列秸秆覆盖增加为甚,增加了124%。土壤微生物数量随着土层的加深而逐渐减少。

The field experiment was conducted at the station of arid land farming of Gansu Agricultural University. The two rotation series (the rotation of spring wheat-field pea and the rotation of field pea-spring wheat) were studied for 2 years. The results were as follows: the soil microbial quantity was higher in the no-till and mulch treatments compared with conventional tillage. Under no-till treatment the soil microbial quantity increased by 14.9 % with the rotation of spring wheat-field pea, and by 38.4 % with the rotation of field pea-wheat. Under the mulch treatment the soil microbial quantity increased by 30.9 % with the rotation of spring wheat-field pea, and by 124 % with the rotation of field pea-wheat. The soil microbial quantity showed negatively relationship to the depth of the soil.