稻米重金属镉含量预警方法研究

中国是水稻生产量最大的国家，近年来稻米中的重金属特别是镉成为公众关注的对象，也因此控制稻米中的镉超标是政府在农业生产方面最重要的工作之一。笔者研究了3 种大田土壤条件下种植的4 个水稻品种在灌浆结实期间稻米重金属镉的积累规律。结果表明：开花后16 天（第1 次）采样与开花后36 天（第6 次）采样结果存在显著差异，开花后20 天（第2 次）采样和其它5 次（分别为开花后16、24、28、32、36 天）采样结果无显著差异。在开花后20 天进行稻米镉含量检测结果，与谷粒成熟期的结果一致，可将采样时间提前20天，对稻米安全管理起到预警作用。

Study on Early Warning Method of Cadmium Content in Rice

China is the top rice producer in the world, heavy metals especially cadmium in rice (Oryza.sativa L.) has become a hot-spot topic in recent years, thus it is one of the most important work for the government to avoid“cadmium polluted rice”in agricultural production. The accumulation of cadmium in four rice varieties during filling to ripening stages under three field conditions was studied. The results showed that cadmium in rice grains had significant differences between the 16th days (the 1st sampling time) and the 36th days (the 6th sampling time) after flowering, but there was no significant difference between the 20th day (the 2nd sampling time) and the other five sampling times (i.e the 16th, 24th, 28th, 32nd, 36th days after flowering). The results showed that cadmium concentration determined on the 20th days after flowering was similar to those determined afterwards. This early determination could be used to predict cadmium content, and hence used in early warning for safe management.