Abstract: 【Objective】In order to get the information about the characteristics of N, P, K nutrition in different yield level apple orchards. 【Method】 The orchards with ten-year-old apple trees (M. domestica Borkh. cv. Red Fuji/M. hupenensis Rhed) were divided into four types, soil and plant samples were collected and determined at certain time from 1997 to 2000, fertilizer treatments were also conducted in different type orchards. 【Result】The results showed that soil alkaline hydrolyzable N, available P and K concentration had an increasing tendency as yield level increased, indicating the important effect of soil fertility on yield. But the three index value changed much and had low correlation index with yield at the same yield level. At high yield level orchards leaf total N and P, fruit total N were relatively high but leaf total K and fruit total P were relatively low, leaf total K was mostly influenced by yield, and decreased with yield increased. The effect of fertilizer on yield was changed with the change of yield level. Application of P did not increase yield at all four yield level orchards, but as K was concerned, and it was contrary. Application of N increased yield at middle and low yield level orchard. 【Conclusion】Fertilizer application amounts to apple trees should base on not only the yield but also the soil available nutrients. The estimation of K level in apple trees should base on not only the leaf K concentration but also the effect of yield on K absorption and distribution.

Key words: Apple, Yield, Nitrogen, Phosphate, Potassium