水稻对不同土壤中硒酸盐/亚硒酸盐的吸收和富集

通过土培试验研究了在3种类型土壤(红壤、黑土和灰钙土)上施用不同价态硒肥(Na2 SeO3或Na2 SeO4)条件下,水稻地上部硒含量的变化.结果表明,在水稻幼苗期,3种土壤上Se4+硒肥处理的水稻幼苗地上部硒含量高于Se6+硒肥处理.施用Se4+硒肥,红壤、黑土及灰钙土中水稻幼苗的硒含量分别为5.76、1.18和1.11 mg· kg-1,分别为对照的2.5、4.7和6.9倍;施用Se6+硒肥,红壤、黑土及灰钙土中水稻幼苗的硒含量分别为4.70、0.66和0.73 mg·kg-1.在水稻成熟期,施用Se4+硒肥后,红壤、黑土及灰钙土中水稻籽粒中硒含量分别由对照中的0.34、0.05和0.05 mg·kg-1增加到0.94、0.14和0.20 mg·kg-1;施用Se6+硒肥后,红壤、黑土及灰钙土中水稻籽粒中硒含量分别为1.13、0.12、0.16mg·kg-1.不同价态硒肥处理和土壤类型对水稻幼苗和成熟地上部硒含量都有显著影响.在pH值低的红壤上施用Se6+硒肥效果更好,而在pH值高的黑土和灰钙土上施用Se4+硒肥效果更好;从环境风险和硒对植物毒性的角度考虑,硒肥以亚硒酸盐的形式施用比较好.

Uptake and accumulation of Se by rice in different soils supplied with selenite or selenate

Pot culture experiment was carried out to study the effects of soil types and selenium (Se) fertilizers on the selenium uptake and accumulation by paddy rice. The results showed that, at the rice seedling stage, the Se concentrations in the selenite-treated plants were higher than that in the selenate-treated plants in all types of soils. When supplied with Na₂SeO₃ in the soils, the concentrations of Se in the rice seedlings were 5.76, 1.18 and 1.11 mg·kg^-1 for the red soil, black soil and sierozem, 2.5, 4.7 and 6.9 times that of the control, respectively. When supplied with Na₂SeO₄ in the soils, the concentrations of Se in the rice seedlings were 4.7,0.66 and 0.73 mg·kg^-1 for the red soil, black soil and sierozem, respectively. After adding selenite in the soils, the concentrations of Se in the rice grains increased from 0.34, 0.05 and 0.05 mg·kg^-1 in the control up to 0.94, 0.14 and 0.20 mg·kg^-1 for the red soil, black soil and sierozem, respectively. And the concentrations of Se in rice grains were 1.13, 0.12 and 0.16 mg·kg^-1 for the red soil, black soil and sierozem, respectively, after adding selenate in soils. In summary, soil types and selenium fertilizers both significantly affected the selenium concentrations in rice. Selenate fertilizer was more efficient in the red soil with lower pH value. However, in the black soil and sierozem with higher pH value, selenite fertilizer was more efficient. Considering the environmental risk and plant toxicity of Se, selenite fertilizer application in the soils is better.