连续周年耕作对砂姜黑土农田蓄水保墒及作物产量的影响

【目的】筛选利于改善黄淮区砂姜黑土农田蓄水保墒效果及提高作物产量的夏玉米-冬小麦周年耕作方式。【方法】在秸秆全量还田条件下设置5个夏玉米季-冬小麦季周年耕作方式处理:免耕-旋耕(对照)、免耕-深耕、深松-旋耕、深松-免耕、免耕-免耕,通过多年定位试验研究周年耕作方式对砂姜黑土农田土壤容重、土壤水分及作物籽粒产量的影响。【结果】与对照处理相比,免耕-深耕处理显著降低夏玉米收获期15—25 cm土层土壤容重和冬小麦收获期20—35 cm土层土壤容重,深松-免耕和深松-旋耕处理显著降低夏玉米收获期15—40 cm土层土壤容重和冬小麦收获期20—25 cm土层土壤容重,而免耕-免耕处理显著增大夏玉米收获期0—10 cm土层土壤容重和冬小麦收获期5—20 cm土层土壤容重。免耕-深耕、深松-旋耕和深松-免耕处理显著增加夏玉米收获期0—40 cm土壤贮水量,而深松-旋耕和免耕-免耕处理却降低冬小麦收获期0—40 cm土壤贮水量。与对照免耕-旋耕处理相比,深松-免耕处理提高夏玉米-冬小麦整个周年内20—40 cm土层土壤含水量,免耕-免耕处理提高作物收获期40—160 cm土壤含水量,而深松-旋耕处理在冬小麦收获期则降低40—160 cm各土层土壤含水量。深松-旋耕和深松-免耕处理显著增加夏玉米-冬小麦周年籽粒产量,增幅分别为7.67%和10.21%,免耕-深耕处理冬小麦籽粒产量增加而夏玉米产量降低,最终周年籽粒产量降低0.44%,免耕-免耕处理夏玉米-冬小麦周年籽粒产量降低2.19%。【结论】深松-旋耕和深松-免耕处理能够降低土壤容重、提高作物籽粒产量,其中深松-免耕处理能够改善土壤蓄水保墒能力,产量及经济效益增加效果较优,可作为相对较适宜的黄淮区砂姜黑土农田夏玉米-冬小麦周年耕作方式。

Effects of Annual Continuous Tillage on Soil Water Conservation and Crop Yield in Lime Concretion Black Soil Farmland

【Objective】 The aim of this study is to select the appropriate tillage practices for improving soil water conservation and increasing crop yield of lime concretion black soil farmland in the summer maize and winter wheat rotation system. 【Method】Under straw returning conditions, the effects of five summer maize-winter wheat annual tillage practices (no tillage-rotary tillage, no tillage-deep tillage, subsoiling tillage-rotary tillage, subsoiling tillage-no tillage, no tillage-no tillage) on soil bulk density, soil water content and grain yield were studied through field location experiment in summer maize and winter wheat rotation system of Huanghuai region, China. 【Result】 Compared with no tillage-rotary tillage, no tillage-deep tillage significantly decreased soil bulk density in 15-25 cm soil layer during the maize harvest period and in 20-35 cm soil layer during the wheat harvest period. Subsoiling tillage-rotary tillage and subsoiling tillage-no tillage significantly decreased soil bulk density in 15-40 cm soil layer during the maize harvest period and in 20-25 cm soil layer during the wheat harvest period. No tillage-no tillage significantly increases soil bulk density in 0-10 cm soil layer during the maize harvest period and in 5-20 cm soil layer during the wheat harvest period. No tillage-deep tillage, subsoiling tillage-rotary tillage and subsoiling tillage-no tillage significantly increased soil water storage in 0-40 cm layer during the maize harvest period, but subsoiling tillage-rotary tillage and no tillage-no tillage significantly decreased soil water storage in 0-40 cm layer during the wheat harvest period. Compared with no tillage-rotary tillage, subsoiling tillage-no tillage increased soil water content in 20-40 cm soil layer during the whole growth period, no tillage-no tillage increased soil water content in 40-160 cm soil layer during the crop harvest period, but subsoiling tillage-rotary tillage decreased soil water content in 40-160 cm soil layer during the wheat harvest period. Compared with no tillage-rotary tillage, subsoiling tillage-rotary tillage and subsoiling tillage-no tillage significantly increased annual grain yield by 7.67% and 10.21%, respectively. No tillage-deep tillage decreased maize yield but increased wheat yield that finally resulted in decrease of the annual grain yield by 0.44%. The grain yield of summer maize and winter wheat decreased by no tillage-no tillage, the annual yield decreased by 2.19%. 【Conclusion】 Subsoiling tillage-rotary tillage and subsoiling tillage-no tillage could decrease soil bulk density, increase grain yield of summer maize and winter wheat. Especially, subsoiling tillage-no tillage could improve the potential of soil water conservation, and also could have the optimum effects on increasing grain yield and economic benefit. Therefore, subsoiling tillage-no tillage can be selected as an appropriate tillage practice in lime concretion black soil farmland.