Effect of Potato Continuous Cropping on Soil Nutrients in Dry land

[Objective] The study was to provide the guidance for improving potato continuous cropping soil.[Method] With soil samples of potato continuous cropping for 0,3,5 a from Tangjiabao village,Tuanjie Town,Anding region and samples of potato continuous cropping for 0,3,7a from Huichuan Town,Weiyuan County Dingxi City,Gansu Province as the materials,the effects of potato continuous cropping years on soil nutrient content and pH value were studied.[Result] With the increase of potato continuous cropping years,the contents of total N,P,K in soil of 2 regions totally showed decreasing trend,but their differences with different continuous cropping years were not significant.The contents of available N,P,K were decreased with different degrees.The contents of Fe and Mn were decreased while those of Cu and Zn had no obviously change.The pH value of soil in Tangjiabao region showed increasing trend and that in Huichuan region showed as continuous cropping for 3 a continuous cropping for 7 a continuous cropping for 0 a.[Conclusion] The continuous cropping of potato broke the balance of soil nutrient and change the physical and chemical properties of soil.