富硅肥料和水分管理对稻米镉污染阻控效果研究

在已筛选出的施硅方式(基施和叶面喷施相结合)基础上,选择典型单一镉污染稻田土壤(pH=4.97,总Cd 4.1 mg·kg~(-1)),并结合2种稻田水分管理方式,进一步开展不同水肥管理方式对常规早稻(湘早籼45)和杂交晚稻(丰源优299)的3个生育期内各部位中Cd含量及成熟期生物量的影响研究.实验设计4个处理:不施硅肥+常规间歇淹水措施(CK)、不施硅肥+全生育期淹水措施(W)、2种硅肥配施+常规间歇淹水措施(SiLsi)、2种硅肥配施+全生育期淹水措施(SiLsi+W).结果表明,4个处理下,早晚稻试验结果基本一致,但各试验处理对晚稻的阻镉效果更加明显;与CK相比,各处理都能显著降低水稻籽粒中Cd的含量且不会明显影响水稻产量,其中以SiLsi+W对籽粒的降Cd效果最佳(晚稻精米中Cd的含量为0.12 mg·kg~(-1),达到了国家粮食安全生产标准:Cd0.2 mg·kg~(-1)),分别使晚稻谷壳、糙米和精米的降Cd幅度达到93.65%、86.70%和91.18%,W和Si Lsi处理的降Cd效果次之.因此,SiLsi+W可作为一种有效的稻米镉污染控制技术.

Mitigation of Cd accumulation in rice(Oryza sativa L.) with Si fertilizers and irrigation managements

The Si fertilization named SiLsi (Si fertilizer as a basic fertilizer and foliar spray) was selected in our previous study. In order to explore the effects of SiLsi with water management on Cd concentrations in rice parts and dry biomass of early rice (Xiangzaoxian 45) and late rice (Fengyuanyou 299), there were four treatments, including non-used silicon fertilizers with conventional irrigation (CK), non-used silicon fertilizers with irrigation in the whole stages (W), SiLsi combined with conventional irrigation (SiLsi) and SiLsi combined with irrigation in the whole stages (SiLsi+W), were employed in single Cd contaminated soil under greenhouse. The results showed that the concentrations of Cd in husk, brown rice and polished rice significantly decreased with all treatments except for CK, while the reduction in the rice yields was non-significant. Among the four treatments, the concentrations of Cd in edible grains for late rice were the lowest with SiLsi+W treatment, followed by the application of W and SiLsi. The Cd concentrations in husk, brown rice and polished rice were reduced by 93.65%, 86.70% and 91.18% with SiLsi+W treatment, respectively.Therefore, the application of SiLsi+W would be regarded as one of effective technologies for mitigation of Cd accumulation in rice.