改良-农艺综合措施对水稻吸收积累镉的影响

Impacts of Optimized Agronomic Regulation Management on Cadmium Absorption and Accumulation by Late Rice

通过田间原位小区试验,以湖南冶炼区周边典型单一Cd污染稻田为研究对象,选取晚稻中优978为供试品种,在水稻孕穗末期施加石灰,同时采取后期持续淹水的综合调控措施,分析水稻5个关键生育期内各器官中Cd含量,探索改良-农艺综合措施对水稻吸收积累Cd的影响。结果表明,与采用传统农艺管理措施的对照区水稻相比,改良-农艺综合措施管理下的晚稻增产33.24%,糙米中Cd含量降低39.32%。采用该措施有可能使得土壤中Cd元素最终更易富集在水稻的根、茎、叶等不可食用部分,从而在一定程度上降低了水稻穗部的Cd累积量;孕穗末期施加石灰结合后期持续淹水的措施可有效阻控Cd向稻米中迁移,降低稻米中Cd的含量。该措施是一种经济、有效的稻米Cd污染控制技术,具有良好的推广应用前景,为镉污染农田的稻米安全生产提供有效的科学支持和理论依据。

An in situ field experiment was conducted in a Cd contaminated paddy soil to reveal the effects of optimized agricultural management strategy on Cd absorption and accumulation by rice, in the smelting area of Hunan Province. Taking hybrid rice（named Zhong you 978） as an sample in this experiment, lime application at end of booting stage combined with following continuous water-logging was selected as optimized agricultural management, simultaneously traditional agricultural management as a control. To evaluate effects of optimized agronomic management on Cd uptake by rice, the concentrations of Cd in different rice tissues at five key growth stage were examined. Results showed that, rice yield increased by 33.24% in optimized agronomic management of lime application and subsequent continuous water-logging treatment compared to control treatment, Cd concentration of brown rice decreased by 39.32% compared to control treatment. So, lime application at end of booting stage combined with following continuous water-logging was an effective measure to reduce rice Cd concentration standard exceeding risk and showed favorable practicality because of its easy operability, and also can provide scientific support and basis for food safety production and supervision.