秸秆还田量对小麦-玉米轮作中土壤理化性质及作物产量的影响

Effects of Amount of Returned-straw on Soil Physical and Chemical Properties,Crop Yield in Wheat-maize Rotation System

[目的]研究秸秆还田量对一年两熟小麦－玉米轮作制度下土壤理化性质的影响。[方法]通过田间试验，研究秸秆不还田，50％小麦、玉米秸秆还田，100％小麦、玉米秸秆还田，150％小麦、玉米秸秆还田对麦－玉轮作体系中土壤容重、有机质和养分含量，以及小麦和玉米产量的影响。[结果]秸秆还田可以降低土壤容重，增加土壤有机质含量，提高土壤养分库容。50％、100％和150％秸秆还田条件下，土壤容重降幅为1．41％～9．15％，土壤有机质含量增加0．02～0．04 g／kg，土壤碱解氮、有效磷、速效钾、全钾含量分别增加6．64～9.00、3.37～4.07、10．33～19．00、40．00～120．00 mg／kg。不同秸秆还田量均能提高小麦、玉米产量，产量增幅分别为7．57％～13．16％、16．29％～26．06％。[结论]秸秆还田量达到150％时，在土壤理化性质及作物产量方面出现转折，建议不超过100％秸秆还田为宜。

[Objective] The aim was to study effects of amount of returned-straw on soil physical and chemical properties in wheat-maize rota-tion system.[ Method] Through field experiment, effects of straw not returned to field, 50%, 100%, 150% wheat, maize straw returned to field on soil bulk density, organic matter, nutrient content, wheat and maize yield in wheat-maize rotation system were studied.[ Result] The results showed that returned-straw decreased the soil bulk density by 1.41%-9.15%, increased the soil organic matter content by 0.02 -0.04 g/kg, increased available nitrogen by 6.64-9.00 mg/kg, increased available phosphorus by 3.37-4.07 mg/kg, increased available potassium by 10.33-19.00 mg/kg, increased total potassium by 40.00 -120.00 mg/kg respectively.And it also increased wheat yield and maize yield by 7.57%-13.16%and 16.29%-26.06%respectively.[Conclusion] Excessive amount of straw returned 150%was not ben-efit for farmland productivity because its negative turning point in soil physical-chemical properties and crop field.It was suggested the amount of returned-straw was not more than 100%.