氮肥对小白菜生长及硝酸盐积累的影响

目的]研究氮肥对小白菜（Brassica rapa L.）生长及硝酸盐积累的影响。方法]通过盆栽试验分析了不同氮肥施用量对小白菜生物量、硝酸盐和亚硝酸盐含量以及硝酸还原酶活性的影响。结果]小白菜的生物量随着氮肥施用量的增加而增加,但当氮肥施用量达0.20 g/盆后,再增加用量增产效果已不明显;小白菜中硝酸盐含量随着施氮量的增加呈直线上升,而对照的硝酸盐含量随生育期的延长而降低;小白菜中硝酸还原酶活性与硝酸盐含量变化趋势一致;小白菜中亚硝酸盐含量随着施氮量的增加缓慢上升,但各处理亚硝酸盐含量均未超标。结论]该研究可为小白菜种植时合理施肥提供理论依据。

Effects of Nitrogen Fertilizer on Growth and Nitrate Accumulation of Brassica rapa L.

Objective] The aim was to study the effects of nitrogen fertilizer on growth and nitrate accumulation of Brassica rapa L..Method] With the pot experiments,the effects of different nitrogen consumption on plant biomass,content of nitrate and nitrite,and nitrate reductase activity of Brassica rapa L.were studied.Result] The results showed that the biomass increased with the increase of nitrogen consumption,but it increased scarcely when nitrogen consumption exceeded 0.20 g per pot.The content of nitrate rised in a linear upward trend with the increase of nitrogen consumption,but the content of contrast's nitrate decreased with the prolongation of growing period.The nitrate reductase activity had the same trendline of change with content of nitrate.The content of nitrite rised slowly with the increase of nitrogen consumption,whereas it was all below national standards.Conclusion] The study can provide theoretical basis for reasonable fertilization in plant of Brassica rapa L.