Effect of N and S supply on growth and organo-sulfur compounds of Zhangqiu spring onion

Effect of N and S supply on growth and organo-sulfur compounds of Zhangqiu spring onion was investigated in a potted soilless experiment. The results indicated that growth and organo-sulfur compounds of spring onion were influenced by N, S and their interactions significantly. N supply promoted plant growth and increased shoot N concentration and uptake, and S supply enhanced shoot S concentration and uptake. Concentration of organo-sulfur compounds decreased with N supply increasing under deficient S condition, and sufficient N and S supply increased organo-sulfur concentration. The highest organo-sulfur concentration (7.23 μmol/g, FW) was observed at N 12.0 mmol/L and SO42- 4.00 mmol/L, however, excessive N supply (N 24.0 mmol/L) retarded plant growth and decreased concentration of organo-sulfur compounds. Therefore, N could regulate growth and organo-sulfur compounds of Chinese spring onion with sufficient S supply.