Study on Optimization of N,P and K Fertilizer on High Yield Tomato Cultivation in Growing Media

Application of saturated D-optimal design,total of 10 treatments,experiment on effect of nutrient N,P and K on yield of long term tomato cultivation was conducted by directly supplying solid N,P and K fertilizer(mixture of organic and inorganic fertilizers) in eco-organic type soilless culture system,related models between fertilization amount and yield at different growth stage were established.The results indicated that N,P and K nutrient had significant effects on tomato early,middle and late yield.The optimum fertilization amount of N,P_2O_5 and K_2O were 0.72(g/plant/time,the same as the following),0.32 and 1.04 respectively during early growing stage of tomato.The demand for N and K increased during middle growth period,the optimum fertilization amount of N,P_2O_5 and K_2O were(0.85),0.22 and 1.40 respectively.And then demand for N and K slightly decreased during late growth period,the optimum fertilization amount of N,P_2O_5 and K_2O were 0.78,0.25 and 1.27 respectively.