Effects of nitrogen,phosphorus and potassium on cucumber facilities cultivation

In order to optimize fertilization technique and realize high yield and fine quality of facility cultivation cucumber,effects of N,P,and K on cucumber was studied through 3414 fertilizer trial.The results showed that the relation of N and K application and cucumber yields was accordant with the law of diminishing returns.And the cucumber yields appeared the trend from increasing to decreasing with the N and K fertilizer increased.The cucumber yields decreased with the P fertilizer increased.N and K combined application showed positive interaction.However NP and NK showed negative interaction.The cucumber nitrate contents were decreased with N fertilizer increased when the PK level was at moderate level.There was significant regression relationship between N application rate and cucumber nitrite content.And there were no significant regression relationship between PK application rate and cucumber nitrite content.There were no significant different on cucumber protein and Vc in different treatments.And there were little fitness between NPK application rate and cucumber protein and Vc.The cucumber plants should be absorbed N 0.296 kg,P2O5 0.166 kg and K2O 0.517 kg for 100 kg yield.In the experiment,the optimal economical fertilizer application rate was N 150.0 kg/hm2,K2O 409.5 kg/hm2,with no or little P fertilizer.