Influence of interaction between nitrogen and sulfur on N,  P,  K and S absorption and distribution of Chinese spring onion

Using split plot design, a pot experiment with sand culture was conducted to investigate the effects of nitrogen and sulfur interaction on adsorption of N, P, K and S nutrients in Chinese spring onion under different N and S level. The results showed that the different concentrations of N and S had significant influence on the N, P, K and S contents in each onion organ. With increases of N and S level in the nutrient solution, the dried matter and the uptake of N, P, K and S in plant was significantly raised, and the dried matter decreased when 6.69 mmol/L of sulfur level was supplied (S4). Though it was significantly higher than the treatment for 0.01 mmol/L (S0), the dry matter and absorption of N, P, K and S in S4 treatment were lower than that in 1.68 mmol/L (S1) treatment, and lowered by 7.97%, 16.37%, 10.24%, 9.06% and 5.77% respectively. The effects of the N and S levels and their interaction were significant on the N, P, K and S distribution in almost organs of Chinese spring onion, while the response to S level was less sensitive than N level. In conclusion, for improving the mineral nutrition status and the dry matter of Chinese spring onion, the nutrient solution containing N 16.00 mmol/L and S 1.68-3.35 mmol/L is an optimal choice.