Influence of nitrogen and sulfur interaction on growth and quality of Chinese spring onion Influence of interaction between nitrogen and sulfur on N,  P,  K and S absorption and distribution of Chinese spring onion Effects of Sulfur on Growth and Key Enzyme Activities Involved in Nitrogen and Sulfur Assimilation in Chinese Spring Onion Effects of Sulfur on Growth and Key Enzyme Activities Involved in Nitrogen and Sulfur Assimilation in Chinese Spring Onion Effects of silicon on mineral element uptake and distribution, yield and quality of Chinese spring onion