Abstract: Soil available nutrients，one year fertilization and apple yield of 915 mature‘Fuji’apple
orchards in Loess Plateau of Shaanxi were investigated. An eight-year located experiment was carried
which studied effects of nitrogen（N），phosphate（P）and potassium（K）on Fuji apple yield，weight per
fruit，Meanwhile，the change of agronomic efficiency（AE）and fertilizer contribution（FCR）was analyzed.
The result showed that average values of soil alkaline N，available P，available K and organic matter（OM）were 60.1 mg · kg^-1，17.7 mg · kg^-1，173.0 mg · kg^-1 and 12.6 g · kg^-1 respectively. The soil nutrient
distribution ranges of the highest frequency were alkaline N 40–60 mg · kg^-1，available P 10–20
mg · kg^-1，available K 150–200 mg · kg^-1，and OM 10–15 g · kg^-1 respectively. The correlation between
alkaline N，available P and apple yield reached very significant and significant level respectively，however
that between available K，OM and apple yield were not significant. The average fertilizers application rates
were N 454.5 kg · hm^-2，P2O5 327.7 kg · hm^-2，K2O 313.2 kg · hm^-2 and organic manure 4.7 t · hm^-2 in local
apple orchard，respectively. In addition，the highest frequency fertilizer rate of N，P and K were same，
within 200–400 kg · hm^-2. Using manure accounted for only 26.6 percent in these areas. Correlations
between fertilizer rates of N，P，K，apple yield and soil available nutrients reached extremely significant
and significant level. The effects of N，P，K on apple yield，weight per fruit，their AE and FCR all changed
by alternate bearing years，among that，N had more significant effects on apple yield，weight per fruit，
AE and FCR than P and K. P had more significant effects on apple yield than K in heavy fruiting year，but
no significant difference between P and K in normal year and light fruiting year. There was no significant
difference between P and K on weight per fruit in heavy fruiting year and normal year，but K was
significantly higher than P in light fruiting year. The order of N，P，K on AE were N > P > K in heavy
fruiting year and normal year，and N > K > P in light fruiting year，respectively. The order of N，P，K on
FCR were same as the former.

Key words: apple, soil, available nutrient, long-term fertilization, yield, Loess Plateau