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耕作方式对土壤微生物数量及活性有重要的影响 ,虽然前人对不同耕作方式下土壤微生物及土壤化学之间的关系作了大量的研究 ,但关于耕作方式对土壤微生物生物碳Csmb影响的研究很少 ,尤其是关于Csmb与作物氮利用之间的关系研究更少。为确定作物生长季节免耕或常规耕作以及取样部位对Csmb的影响 ,在种植青贮玉米的试验地免耕或常规耕作 3a后 ,选取其第四生长季进行研究。免耕处理下 ,0～ 3 8cm土层和 3 8～ 7 5cm土层的Csmb分别是常规耕作处理下的 87%和 33%。免耕处理下行内取样 0～ 3 8cm土层的Csmb与时间呈线性下降关系 ,在作物生长季节Csmb下降约为 2 9% ,同样对其它取样深度的样品分析 ,其Csmb变化不显著 ,而且季节之间差异也不明显。两种耕作方式下行间取样样品的Csmb明显增加 ,在前人研究中尽管不同的耕作方式使得土层Csmb不同 ,但对于实际生产并没有产生实质性影响 ,因为前人试验结果表明耕作方式不同没有对青贮作物利用肥料中的氮或土壤中的氮发生改变
Tillage practices have an important impact on the amount and activity of soil microbes. Although previous studies on the relationship between soil microbes and soil chemistry under different tillage practices have done a great deal of research, the effects of tillage practices on soil microbial biocarbon Csmb Fewer, in particular, there is less research on the relationship between Csmb and crop nitrogen utilization. In order to determine the effect of no-till or conventional tillage and the sampling site on Csmb in the growing season, the fourth growing season was selected after no-tillage or conventional tillage for 3 years. Under no-tillage treatments, Csmb of 0 ~ 38cm soil layer and 38 ~ 75cm soil layer were 87% and 33% under conventional tillage treatment, respectively. The Csmb in 0 ~ 38cm soil layer sampled in no-tillage treatment decreased linearly with time, and the Csmb decreased by 29% in the crop growth season. Similarly, the Csmb change was insignificant in other sampling depth samples, and the season The difference is not obvious either. The Csmb of down-sampled samples in the two tillage modes increased significantly. Although different tillage methods resulted in different soil Csmb in the previous studies, they did not have any substantial impact on the actual production because the previous experimental results showed that the tillage modes were different Use of silage crops Nitrogen in fertilizers or nitrogen in soil is changed