Abstract:To investigate the effect of corn-alfalfa intercropping on maintaining soil fertility and improving crop yields,soil nutrients and crop yield in both corn-alfalfa intercropping and corn monocropping(CK) lands were studied on different slopes(5°,10°and 15°).The results indicate that,soil nutrients showed little difference between corn-alfalfa intercropping and corn monocropping land before sowing,but significant changes were showed after harvest,as nutrient losses of intercropping were less than monocropping.Difference in contents of organic matter,total N,total phosphorus,nitrate,ammonium nitrogen,available phosphorus and available potassium between intercropping and monocropping were 0.04g/kg,0.05g/kg,0.01g/kg,1.6mg/kg,1.2mg/kg,0.1mg/kg,3.2mg/kg.Soil nutrients at lower slopes were higher than that at upper slopes under both crop patterns,while this nutrients differences among slopes were less in intercropping than monocropping.And the differences on contents of organic matter,total N,total phosphorus,nitrate,ammonium nitrogen,available phosphorus and available potassium were 0.13g/kg,0.05g/kg,0.01g/kg,0.5mg/kg,0.3mg/kg,0.2mg/kg and 0.4mg/kg between lower slope and upper slope.Corn yields of intercropping were higher than corn yields of monocropping.From 5°to 15°,corn yields of intercropping were 7 426.3,7 280.3and 6 802.5kg/hm2,which was higher by 1.35%,0.92% and 0.89%,respectively,compared to corn yields of monocropping.Moreover,alfalfa yield of intercropping reached the local level,which indicated that the pattern of corn-alfalfa intercropping was feasible in Weibei dryland.