Compound Fertilizers With Different Nitrogen Forms On Growth And Nitrogen Use Efficiency Of Maize And Chinese Cabbage

Pot experiments and field experiments were carried out to investigate the effect of compound fertilizer with different nitrogen forms on the growth of maize and Chinese cabbage. The results showed as follows:1 In the pot experiment, maize and Chinese cabbage applied with compound fertilizer containing both NO₃^--N and NH₄⁺-N had significantly higher biomass accumulation, dry weight of shoot and root. In Udic Isohumisols, biomass accumulation of maize were increased by 44.3% and 43.5% with application of both NO₃^- and NH₄⁺ in different ratio, and in Udic Cambosols were increased by 25.8% and 34%. Biomass accumulation of Chinese cabbage were increased by 44% and 39%. However, in different soils the effect of the same compound fertilizer is also different.2 It was shown that addition of NO₃^--N in compoud fertilizer could increase nitrogen accumulation and nitrogen use efficiency of maize and Chinese cabbage in Udic Isohumisols and Udic Cambosols.3 Nitrogen forms in compound fertilizer affected the quality of Chinese cabbage, which included soluble reducing sugar and Vc content. It was shown that combination of NO₃^--N and NH₄⁺-N increased quality of Chinese cabbage. The nitrate content in the vegetable was higher than others which were applied with other compound fertilizer. However, the nitrate content was still below the safety standard.4 In the field of Udic Isohumisols, the maize yield increased 37.29% and 37.74%, and in Udic Cambosols 20.2% and 26.7% with the application of NO₃^- and NH₄⁺ together. The yield of Chinese cabbage increased 48% and 41%.5 Crop with the treatment of compound fertilizer containing urea alone could undergo the dange of NH₃ toxicity in the early growth stage and decreased germination rate. Urease inhibitor should be used under such condition.To conclude, the application of compound fertilizer with different nitrogen forms can supply nitrogen, phosphorus, potassium and other nutrient to crops. The compoud fertilizer with both NO₃^--N and NH₄⁺-N could promote the grown of root and then improve their ability to take up the nutrient in soil.