Study on soil physical and chemical characteristics and fertilizer application at early summer in Fuji apple orchard in semi-humid and liable-drought region

By the field investigation and soil chemical analysis,a study on physical and nutrient characteristics of soil 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. Results showed that a significant difference was obtained for soil physical and nutrient characteristics between high-yield and low-yield orchards.Soil pH in high-yield orchard was markedly lower than that in low-yield orchard while soil conductance and the contents of soil organic matter,available nitrogen,available phosphorus,available potassium and microelements in high-yield orchard were significantly higher compared with low-yield orchard.These nutrients contents were in middle and rich level,which were accorded with standard of them in high-yield and good-quality apple orchard,but the nutrients contents in low-yield orchard were in middle or inadequate level.In addition,the nutrients contents in 0～20 cm soil layer in both of two typical orchards were higher than other layers.Furthermore,the significant or markedly significant correlations were found among organic matter,available nitrogen,available phosphorus and available potassium.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 included optimizing the structure of fertilization for low-yield orchard,increasing supply of organic,nitrogen and phosphorus fertilizer and supplemental supply of potassium fertilizers and microelements fertilizers.