Study on optimization of NPK fertilization scheme of tomato in late autumn

The effects of nitrogen (N), phosphorus (P) and potassium (K) on yield and quality of tomato were studied with the design of three factors and quadratic saturation Doptimal regression (310). According to the data obtained, a mathematical model was developed, in which N, P and K were independent variables and tomato yield and quality parameters were dependent variables. The model analysis shows that yields and quality of tomato are significantly influenced under the N, P and K applications, and there are significant interactive effects between every two factors. Among the three factors, K has the greatest effects on yield and quality of tomato. At the lower levels, the yields and quality are improved along with the increase of N, P and K, and are decreased when N, P and K are applied too much. Obtained by computer simulation in this experiment, the yields could reach to 150 t/ha and quality grade could pass 95 when the fertilizer rates are N 520.2-758.4 kg/ha, P2O5 294.8-367.3 kg/ha and K2O 1051.5-1299.8 kg/ha. The suitable ratio of N∶P2O5∶K2O is about 1∶0.52∶1.84.