有机废弃物与化肥配施对污染稻田水稻产量及糙米镉铅含量的影响

Effects of Combined Application of Organic Wastes and Fertilizer on Rice Yield and Contents of Cd and Pb in Brown Rice in Contaminated Paddy Field

通过湘潭和湘阴两地的大田试验,研究了污染稻田土壤中有机废弃物(猪粪、稻草和菜饼)与化肥配施对当季水稻产量及糙米Cd、Pb含量的影响。结果表明:与单施化肥(对照)相比,减少化肥用量的同时配施有机废弃物的水稻产量变化不明显。当菜饼施用量为3 000 kg/hm2时,水稻糙米的Cd、Pb含量显著降低;与对照相比,湘潭稻草和猪粪两个处理的水稻糙米Cd、Pb含量差异不明显,而湘阴施稻草4500 kg/hm2的糙米Cd降低了20.0%(P<0.05),但糙米Pb含量降低不明显,施猪粪15 000 kg/hm2的糙米Cd、Pb含量分别降低了24.1%(P<0.05)和19.7%(P<0.05)。因此,化肥减量的同时配施有机肥不会导致水稻明显减产,并能在一定程度上降低污染土壤中水稻糙米的Cd、Pb累积,其效果与有机废弃物的施用量及土壤性质等密切相关,但有机废弃物自身重金属含量可能是影响其效果的一个障碍因子。

The effects of combined application of organic wastes （pig manure, straw and rape-seed cake） and fertilizer on seasonal rice yield and contents of Cd and Pb in brown rice in contaminated paddy field were studied through two field tests in Xiangtan and Xiangyin, respectively. The results showed that in comparison with control （single application of fertilizer）, rice yield did not change significantly when reducing fertilizer rate and combining with organic wastes at the same time. As applying amount of rape-seed cake reached 3 000 kg/hm2, the contents of Cd and Pb in brown rice declined apparently. In comparison with control, contents of Cd and Pb in brown rice did not show an obvious difference in both treatments of straw and pig manure in Xiangtan, but Cd content decreased by 20.0% （P〈0.05） and Pb content did not show a significant decrease when applying straw of 4500 kg/hm2, and contents of Cd and Pb respectively decreased by 24.1% （P〈0.05） and 19.7% （P〈O.05） when applying pig manure of 15 000 kg/hm2 in Xiangyin. Therefore, reducing fertilizer rate and combing with organic wastes at the same time will not cause significant yield reduction of flee, and can reduce accumulation of Cd and Pb in brown rice from contaminated field to some extent, furthermore, the effect closely related to the amount of organic wastes and the nature of the soil, but heavy metal content of the organic wastes may affect the effect.