Study on Leaf Nutrients Condition and Corresponding Fertilizer Application Technique at Early Summer in Fuji Apple Orchard in Semihumid and Liable-drought Region

By the field investigation and leaf chemical analysis,a study on nutrient characteristics of leaf was carried out in high-yield(≥22 500 kg/hm2)and low-yield(18 000 kg/hm2) typical Fuji apple(Malus pumila) orchard in semi-humid and liable-drought region.The aim of this trial was to feed theory basis for fertilization at early summer in orchard.Results showed that the diversity was remarkable between the high yield and low-yield orchard.Nitrogen content in leaf layer in high yield orchards was in middle and rich level,which accorded with standard of nitrogen content in high yield and quality apple orchard,but inadequate in most of low-yield orchards.The content of phosphorus and potassium was rich.On the basis of the nutrients requirement characteristics of apple tree and soil nutrients condition and their availability,we put forward preliminarily the fertilization projects to improve the yield and quality of apple in this area,which named optimizing the structure of fertilization,increasing supply of organic and nitrogen fertilizers and supplemental supply of phosphorus and potassium fertilizers.