不同氮水平对水培小白菜生长及其体内硝酸盐含量的影响

[目的]为乌鲁木齐市生产培育出高产优质、低硝酸盐含量的小白菜品种提供理论性指导依据。[方法]对乌鲁木齐市主要种植的4种小白菜在不同氮水平下生长及硝酸盐含量的影响进行研究。通过对其产量及硝酸盐含量的测定,分析不同水平供氮量对叶菜的硝酸盐累积量影响,比较不同品种间差异,得出硝酸盐在4种小白菜体内的累积规律。从中挑选出品质好、产量高、硝酸盐含量低的品种。[结果]4种小白菜在不同氮处理条件下的生物量表现为四月慢>五月慢>上海青>黑油白菜;硝酸盐含量表现为:上海青>四月慢>黑油白菜>五月慢;五月慢是硝酸盐含量最低,且生物量较高的一种小白菜,含氮量为10 mmol/L为最佳处理浓度。[结论]采取选择硝酸盐累积量较低的蔬菜品种、合理施肥、改良栽培方式、科学采收方法和适当延迟收获及食用前处理等措施是降低蔬菜硝酸盐含量的重要途径。

Effects of Different Nitrogen Levels on the Growth of Hydroponic Brassica chinensis L. and Its Nitrate Content

[Objective] The research aimed to provide theoretical basis for breeding some varieties of Brassica chinensis L.with high yield,good quality and low nitrate content in Urumqi City.[Method] The effects of different nitrogen levels on the growth and nitrate content of 4 main varieties of B.chinensis planted in this city were studied.Based on determining their yields and nitrate contents,the effects of different levels of applied nitrogen amounts on the nitrate accumulation amount in leaf vegetable were analyzed and the accumulation laws of nitrate in 4 varieties of B.chinensis were studied. [Result] The biomass of 4 varieties of B.chinensis under the conditions of different nitrogen treatments showed that Siyueman > Wuyueman > Shanghaiqing >Heiyoubaicai and the nitrate content showed that Shanghaiqing > Siyueman > Heiyoubaicai > Wuyueman.Wuyueman was a kind of B.chinensis with lowest nitrate content and higher biomass and nitrogen content of 10 mmol/L was the optimum treatment concentration.[Conclusion] Taking measures such as choosing low-nitrate vegetable varieties,reasonable fertilization,improving cultivation mode,scientific harvesting method,prolonging the harvest properly and treatment before eating are important approaches of decreasing nitrate content in the vegetable.