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

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。

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

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%.