But there were not the same tendency in different soils and for different nitrification inhibitors,the yield of pakchoi was higher in red vegetable soil than that in alluvial vegetable soil. DCD had the best effect among 3 nitrification inhibitors.

• 3种硝化抑制剂均可不同程度地提高小白菜的产量；也以双氰胺的效果最好；且在红菜园土上的增产效果要比冲积菜园土上显著.