不同耕作措施对冬小麦-夏玉米复种连作系统土壤有机碳和水分利用效率的影响

在连续8年田间定位试验的基础上,分析了关中平原冬小麦 夏玉米复种连作系统2008—2009年连续两个生长季期间不同耕作措施(结合秸秆还田和不还田)对土壤有机碳和水分利用率的影响.结果表明: 相对于传统耕作,保护性耕作有利于土壤有机碳、水分利用效率和作物产量的提高,其中在“深松+秸秆还田”耕作模式下的增幅最高,土壤有机碳含量在0～30 cm土层增幅达到19.5%,水分利用效率和作物产量提高了16.9%和20.5%,而免耕模式则有效提高了0～10 cm土层有机碳含量.在该地区土壤和气候条件下,深松结合秸秆粉碎还田是最理想的耕作模式,最有利于土壤有机碳累积,并提高水分利用效率和作物产量.

Impact of different tillage practices on soil organic carbon and water use efficiency under continuous wheat-maize binary cropping system.

Base on an 8 year field experiment, the effects of tillage practices coupled with or without straw return on the soil organic carbon (SOC) and water use efficiency (WUE) were investigated in Guanzhong Plain during the growing seasons from 2008 to 2009. The results showed that conservation tillage practices (sub-soiling, SS; rotary tillage, RT; no till, NT) improved the SOC, WUE and crop yield compared with conventional tillage (CT), among which, SS coupled with straw return had the highest increment, with increase in SOC content of the 0-30 cm soil layer, WUE and crop yield by 19.5%, 16.9% and 20.5%, respectively. The NT practice effectively increased the SOC content of the 0-10 cm soil layer. Conclusively, under the current soil and clima tic conditions in Guanzhong Plain, sub soiling coupled with straw return is the most efficient tillage practice for promoting SOC accumulation, increasing water-use efficiency and yield.