宁夏引黄灌区不同还田年限对土壤质量及玉米产量的影响OA

To clarify the effect of straw returning years on soil quality and maize yield,this study carried out maize cultivation experiments in the Yellow River irrigation area of Ningxia with straw non-returning plots(CK),straw returning plots for one year(H1),straw returning plots for three years(H3),straw returning plots for four years(H4),straw retur-ning plots for five years(H5)and straw returning plots for six years(H6).The soil physical and chemical characteristics,enzyme activities and maize yield characteristics at the maize harvest stage of different plots were analyzed,and the effects of straw returning years on soil quality and maize growth were comprehensively evaluated.The results showed that straw returning could improve soil physical and chemical properties,increase soil enzyme activity and increase maize yield.Compared with the control(CK)without straw returning,the soil bulk density of the six-year straw returning treatment(H6)decreased by 16.23%,the soil porosity and water content increased by 16.92%and 10.35%,respectively,the soil alkali-hydrolyzed nitrogen content,to-tal phosphorus content and organic matter content increased by 43.21%,42.86%and 21.33%,respectively,and the soil urease activity and alkaline phosphatase activity increased significantly by 33.79%and 35.63%,respectively.With the in-crease of straw returning years,the yield of maize showed an increasing trend.The yield of maize treated with H5 and H6 increased by 12.84%and 11.37%respectively compared with CK.The comprehensive score of H6 treatment was the high-est,indicating that long-term straw returning was beneficial to improve soil physical and chemical properties and increase maize yield.In summary,long-term maize straw returning is an effective measure for soil improvement and maize yield in-crease in the Yellow River irrigation area of Ningxia.