Soil Fertility Evaluation of Walnut Orchards in Wushi County,Xinjiang

【Objective】Through soil fertility evaluation of the walnut orchards,this investigation aims at having a deep insight into the soil fertility status in order to provide the necessity of scientific understanding for fertilization and soil nutrient management of the orchards in Wushi County,Xinjiang. 【Method】Soil organic matter( OM),total nitrogen( TN),total phosphorus( TP),total potassium( TK),alkali- hydrolyzable nitrogen( AN),available phosphorus( AP),available potassium( AK),calcium( Ca),magnesium( Mg),iron( Fe),manganese( Mn),copper( Cu),zinc( Zn) content were determined by means of soil sampling from the orchards,and the evaluation model of soil fertility index( SFI) was set up using the method of principal component analysis( PCA).【Result】In addition to the Ca,Mg,Zn nutrient contents,the vast majority of the walnut orchard soil OM,TN,TP,TK,AN,Fe,Mn,Cu nutrient contents were deficient or not enough,and also about half of the walnut orchard soil AP,AK nutrient contents were insufficient or not plentiful. The orchards with low soil fertility accounted for vast majority,nearly two- thirds,and those with medium soil fertility accounted for less than one third,and those with high soil fertility accounted for a small number,only scattered in few places.【Conclusion】It was suggested that to enhance the fertilization and soil nutrient manage-ment adjusting measures to adapt to the local conditions,the combination of the nutrition diagnosis should be considered in order to achieve the purpose of increasing yield and improving quality of the fruits according to the soil fertility and the soil nutrient status of each walnut orchard in Wushi County. The fertilization and soil nutrient management of soil OM,AN,AP,AK contents increase should be given priority to and sustainable improvement of soil Ca,Mg,Zn of effective supply must be emphasized.