Coupling Effect of Water and Fertilizer on Tomato Yield and Nitrate Content

The quadratic general rotation combination design with two factors(water and fertil-izer) was used to study the effects of water-fertilizer interaction technology on the yield and nitrate content of tomato in Greenhouse.The result indicated:FF0.01(5,7),regression is reliable,presenting the regression relation between the two factors(water quota and fertilizer quota) and analysis items.The significance of fertilizer was bigger than that of water.By analyzing the limit benefit,the limit yield increased with the addition of water and fertilizer,but the limit nitrate content decreased with the addition of water and increased with the addition of fertilizer.By means of computer analysis,the optimal combination scheme for high yield and low nitrate content was obtained: the index of water and fertilizer was 2710.95-2735.25m3/ha and 264.6-280.5kg/ha,respectively.