Optimal NPK fertilization and its effect on naked barley yield in sub-highland region.

Optimal fertilization is imperative in increasing both naked barley(Hordeum vulgare var.nudum hook.f.) yield and fertilizer efficiency in highland region.Field trials were conducted in a highland meadow soil at Zhongdian County,Yunnan province to study the optimal fertilizer rates of nitrogen(N),phosphate(P) and potassium(K) and their effect on highland barley(H.vulgare).The experimental design was an orthogonal rotational combination of 3-factors(N,P and K) and 5-levels.The regression equations were developed to determine the relationship between N,P,K rates and barley yield;and the relationships of N,P and K rates with their effects on the yield.The results showed that,N,P and K fertilization increased barley yields significantly.The fertilizer response order was K P N.Based on the mathematical model calculation and regression analyses,the highest yield of 3909kg/hm2 was obtained when fertilizer rates were N 120kg/hm2,P2O5 120kg/hm2 and K2O 99kg/hm2,respectively.The fertilizer rates for maximum profit were N 30kg/hm2、P2O5 30kg/hm2 and K2O 30kg/hm2,respectively.