Effects of Nitrogen,Phosphorus and Potassium on Yield and Quality of Water Melon

[Objective] The effects of nitrogenous,phosphate and potash fertilizers on the watermelon yield and quality were investigated to provide reference for the high yield and quality.[Method] In the different growth stages of watermelon,the effects of different combinations of nitrogen,phosphorous and potassium were studied.[Result] The fertilization of nitrogen and phosphate showed a significant effect on the yield increase.The content of soluble solids and Vitamin C in watermelon decreased after the usage of the fertilization of nitrogen,while total acid and nitrate content increased.Obvious decrease of the soluble solids and Vitamin C content was observed when the usage of the fertilization of nitrogenous was higher than 300 kg/hm2.Meanwhile,the usage of the P fertilizer led the increases in the content of soluble solids and Vitamin C in Watermelon,which couldn't be raised with excess fertilization of P fertilizer.Nitrate accumulation was obviously promoted with N fertilizer rates and inactivated with K fertilizer rates.[Conclusion] The highest yield of watermelon was obtained at 200-300 kg/hm2 N,100-200 kg/hm2 P2O5 and 100-200 kg/hm2 K2O with higher soluble solids and Vitamin C content and lower Nitrate accumulation and total acid.