Effects of split applications of nitrogen fertilizers on the Cd level and nutritional quality of Chinese cabbage

Abstract

Cadmium (Cd) contamination in soil is an increasingly serious problem. Management of plant nutrients has been proposed as a potentially promising strategy for minimizing Cd accumulation in crops grown in contaminated soil. This study investigated the effects of split applications of nitrogen (N) fertilizers on the Cd concentration in Chinese cabbage (Brassica chinensis L.) plants grown in Cd-contaminated soil. Compared with single applications, split applications of ammonium or urea resulted in significantly lower Cd concentrations, and higher biomass production and antioxidant-associated nutritional quality in the edible plant parts. However, when nitrate was used as the N fertilizer, there were no significant differences between the split and single applications for the same parameters. We conclude that a split application could be more beneficial than a single application method when ammonium or urea is used as the N fertilizer for vegetable cultivation in Cd-contaminated soil.

摘要

目 的

研究不同形态氮肥的分次施用对小白菜镉积累、 产量及品质的影响, 并初步分析了其作用机制。

创新点

首次提出尿素、 铵态氮和硝态氮肥料的分次施用方式可提升镉污染土壤上的作物安全生产。

方 法

选用尿素、 硫酸铵和硝酸钙等 3 种常用氮肥, 通过盆栽试验, 比较了这 3 种肥料的分次施用方法和一次性施用方法对小白菜的镉含量、 生物量以及营养品质的影响。

结 论

在镉污染的条件下, 与一次性施肥相比, 尿素和硫酸铵的分次施肥方法显著降低了小白菜可食部位的镉含量, 增加了可食部位的生物量并改善了抗氧化相关的营养品质指标; 然而, 当硝酸钙作为氮肥时, 小白菜可食部位的镉含量、 生物量以及抗氧化相关的营养品质指标在两种不同的施肥方法之间并无统计学上的显著差异。因此, 在镉污染的土壤上, 当硫酸铵或尿素作为氮肥时, 分次施肥方法比一次性施肥方法更加有利于保障蔬菜的安全生产与品质改善。