Effects of Water and Fertilizers Applied on the Soluble Solid Content in Tomato Under Alternate Partial Root-Zone Irrigation

【Objective】 The effects of irrigation amount and fertilizer rates of nitrogen,phosphorus,potassium and manure on the soluble solid content of tomato were investigated in a pot experiment under alternate partial root-zone irrigation.【Method】Quadratic orthogonal regressive rotation design with five factors was used.A regression model on water and fertilizer and soluble solid content in tomato was established.Single and coupling effects were analyzed.【Result】 The results showed that if other factors were zero codes,the soluble solid content in tomato decreased linearly with irrigation amount,while increased linearly with the fertilizer rates of N,K or manure,but it was not affected by P fertilizer rate.The interaction effects between N fertilizer and manure rate,P fertilizer rate and irrigation amount,K fertilizer or manure rates were presented positive correlation,while they were negatively correlated with N and phosphorus fertilizer rates,in which the interaction effect between P and K fertilizer rate was the largest.【Conclusion】 It was concluded that heavy irrigation was not of benefit to the soluble solid content in tomato,and proper application of fertilizers of N,P,K,or manure could raise the soluble solid content in tomato effectively.