双氰胺对无土栽培菜薹硝酸盐积累的影响

A Study of Dicyandiamide Effect on the Accumulation of Nitrate in Soilless-cultured Brassica campestris

研究了双氰胺对甘蔗渣基质培菜薹硝酸盐积累的影响。结果显示,采收前20 d施用双氰胺的处理,其基质中的NO3--N含量比不施双氰胺处理的低,而NH4+-N含量较高;双氰胺显著降低菜心硝酸盐含量,而对产量无明显影响。

The effect of dicyandiamide （DCD） on the accumulation of nitrate in Brassica campestris L. ssp. chinensis var. utilis Tsen. et Lee. was investigated in the present study. The results indicated that DCD, which was applied at 20 d before harvest of the vegetable, had a significant effect on lowering the amount of NO3^--N and enhancing the level of NH^4＋-N in the substrate. Consequently, DCD suppressed excessive accumulation of nitrate in the vegetable, while yield of the vegetable was not affected by the application of DCD, suggesting that the decrease of nitrate accumulation in vegetable treated with DCD was resulted from the inhibition of nitrification and the reduction of nitrate absorption.