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.
tillage practicelime concretion black soilsoil moisturesoils bulk densitygrain yieldsummer maize and winter wheat