Abstract:Field plot experiment was carried out to study the effect of microelement fertilizer and rare earths on yield and quality of Chinese cabbage and contents of NH4+N and NO3N in tested soil. The results showed that combination of organic manure and NPK fertilizers applied together with microelement fertilizer or rare earths reduced the content of nitrate and nitrites in Chinese cabbage in varying degrees. In comparison with the contrast, nitrate and nitrites contents of Chinese cabbage were reduced by 3.1%–28.2% and 6.4%–43.0% respectively in spring, and reduced by 3.0%–54.5% and 0.0%–20.0% respectively in autumn. Vitamin C content of Chinese cabbage was increased by 18.6%–82.4% in spring and soluble sugar content was increased by 3.6%–67.9% in autumn. NO3N content was reduced by 8.5%–69.9% and NH4+N content was increased by 88.2%–157.4% in plough layer of soils. Synthetic analysis showed that combination of organic manure and NPK fertilizers applied together with Zn fertilizer, not only increased vitamin C and soluble sugar contents, but also reduced nitrate content of Chinese cabbage.