Effect of nutrient management on nitrate accumulation of pakchoi under solution culture

The paper aimed to reduce nitrate accumulation of pakchoi under solution culture by regulating nutrient during the short period just before harvest. The regulating methods are as follows: reducing N content in nutrient, replacing NO3- with NH4+; eliminating N completely from Nutrient; and using Cl- and SO42- as osmoregulation substituting NO3-. All these resulted in lower nitrate content in pakchoi, the experiment also showed adding Cl- and SO42- basing on reducing N amount had better effect on reducing nitrate accumulation of pakchoi, the effect of Cl- was better than SO42-. However, the treatments of eliminating N completely and adding organic acid salt reduced nitrate content significantly and also decreased pakchoi yield.