不同土壤耕作措施与秸秆还田对稻麦两熟制农田土壤活性有机碳组分的短期影响

通过2年（2009-2011年）大田试验，研究不同耕作措施和秸秆还田及其交互效应对稻麦两熟制农田0～7、7～14和14～21 cm 3个土层土壤总有机碳和活性有机碳组分（易氧化有机碳、水溶性有机碳和微生物生物量碳）的影响.结果表明： 秸秆还田处理各土层土壤总有机碳和活性有机碳含量均显著高于无秸秆还田处理；0～7 cm土层，翻耕处理土壤微生物生物量碳含量显著高于旋耕处理，旋耕处理易氧化有机碳含量高于翻耕处理；7～14 cm土层，旋耕处理土壤总有机碳含量显著高于翻耕处理；14～21 cm土层，翻耕处理土壤总有机碳、水溶性有机碳和微生物生物量碳含量均显著高于旋耕处理；翻耕加稻麦两季秸秆均还田处理的总有机碳含量均高于其他各处理.

Short-term effects of different tillage modes combined with straw-returning on the soil labile organic carbon components in a farmland with rice-wheat double cropping

A two-year (2009-2011) field experiment was conducted to study the effects of different tillage modes, straw-returning, and their interactions on the soil total organic carbon (TOC) and labile organic carbon (LOC) components (easily oxidizable organic carbon (EOC), water-soluble organic carbon (WSOC), and microbial biomass carbon (MBC)) at the soil depths of 0-7, 7-14, and 14-21 cm in a farmland with rice-wheat double cropping. In all treatments of straw-returning, the TOC and LOC contents in each soil layer were significantly higher than those without straw-returning. Under plowing tillage, the MBC content in 0-7 cm soil layer was significantly higher than that under rotary tillage, but the EOC content was in adverse. Rotary tillage made the TOC content in 7-14 cm soil layer being significantly higher, as compared with plowing tillage. The TOC, WSOC, and MBC contents in 14-21 cm soil layer under plowing tillage were significantly higher than those under rotary tillage. Plowing tillage combined with rice and wheat straws returning made the soil TOC content being higher than the other treatments.