保护性耕作下西南旱三熟农田土壤水分动态及产量效应

Soil Moisture Dynamics and Crop Yield with Conservation Tillage in Tri-crop Intercropping System of Southwest China

以西南地区麦/玉/薯三熟制种植模式为研究对象,研究了不同保护性耕作模式下旱地土壤水分动态变化、水分利用效率、作物产量和经济效应。结果表明,不同保护性耕作对整个农田生态系统产量和水分利用效率具有显著影响。秸秆覆盖(TS)、地膜覆盖(TM)、秸秆覆盖+地膜覆盖(TSM)和垄作+秸秆覆盖+地膜覆盖(RSM)能改善7,10月份0—60cm土层土壤含水量及贮水量,而垄作(R)、垄作+秸秆覆盖(RS)和垄作+地膜覆盖(RM)的作用不明显。与平作(CK)相比,RSM,RM,RS,TSM,TM,TS和R分别使系统增产10.52%,6.11%,6.77%,4.59%,5.12%,3.15%,1.24%。这些处理对水分利用效率和降水利用效率的增幅分别为1.26%～11.08%,1.27%～10.57%。研究结果说明,从WUE、降水利用效率、产量效应、经济效益这4个方面来看,垄作+秸秆覆盖+地膜覆盖耕作模式综合效益最佳。

Dynamics of soil moisture in root layer,water use efficiency,crop yield,and economic benefits under different types of conservation tillage were studied with the triple crops of wheat-maize-sweet potato in the southwest China.Results indicated that different types of conservation tillage had significant effects on crop yield and water use efficiency.Straw mulching（TS）,film mulching（TM）,straw mulching plus film mulching（TSM）,and ridge plus straw mulching plus film mulching（RSM）increased soil water storage and soil moisture in 0—60 cm soil layer in July and October,while ridge（R）,ridge plus straw mulch（RS）,and ridge plus film mulching（RM）can not remarkably affect the indexes.RSM,RM,RS,TSM,TM,TS,and R increased average yield by 0.52%,6.11%,6.77%,4.59%,5.12%,3.15%,and 1.24%,respectively,compared with CK.The comprehensive effect of ridge plus straw mulching plus film mulching was the best in view of water use efficiency,rainfall use efficiency,crop yield,and economic benefits.