Influence of nitrogen and sulfur interaction on growth and quality of Chinese spring onion

In order to investigate effects of nitrogen and sulfur on growth, yield and quality of Chinese spring onion, the response characteristics of sand potted overwintering Chinese spring onion to N and S fertilization levels were studied by using the split plot design. The results show that the biomasses of onion organs are increased significantly with the solution N increasing, and the higher change of yield is under N 16.00 mmol/L（N2）, which is increased by 50.09 % and 22.46 % under the N 4.00 mmol/L（N1/2） and N 8.00 mmol/L（N1） respectively. Meanwhile the biomasses of all organs are also increased with solution S increasing, but the response is less sensitive than the response to N. The yields are higher while sulfur concentration are 1.68 mmol/L（S1） and 3.35 mmol/L（S2） levels, but the yields begin to decrease when the sulfur concentration reaches to 6.69 mmol/L（S4）. Although the main inclusion reacts differently in response to N and S levels, the organicsulfur compounds (EPY) are increased significantly as the increases of N and S levels. Moreover, combined application of N and S could significantly improve the Chinese spring onions comprehensive quality. The interaction effect of nitrogen and sulfur is significant on growth, yield and quality of Chinese spring onion. The results of comprehensive analysis show that the nutrient solution containing N 16.00 mmol/L（N2） and S 3.35 mmol/L（S2） is optimal to improving the growth, yield and quality of Chinese spring onion..