Bogdan Katja, Schenk Manfred K
Institute of Plant Nutrition, Leibniz Universität Hannover, Herrenhaeuser Str. 2, 30419 Hannover, Germany.
Environ Sci Technol. 2008 Nov 1;42(21):7885-90. doi: 10.1021/es801194q.
Paddy rice is a global staple food which in some circumstances can contain high levels of the toxic element arsenic (As). In order to elucidate factors influencing As dissolution in the soil solution during paddy rice cultivation, rice (Oryza sativa L. "Selenio") was cultivated to maturity in six paddy soils in the greenhouse in 2005 and 2006. Concentrations of Mn, Fe, As, P, and silicic acid in soil solution and As concentrations in rice straw and polished rice grain were determined. There was a close relationship between Fe and As concentrations in the soil solution, suggesting that the major part of dissolved As originated from reduced iron-(hydr)oxide. However, in addition to the factors causing As dissolution in the soil, other factors influenced the uptake of As by rice. The inhibitory effect of indigenous silicic acid in the soil solution on As uptake was clearly shown. This implied that soils with high plant available Si contents resulted in low plant As contents and that Si application to soils may decrease the As content of rice.
水稻是一种全球主食作物，在某些情况下可能含有高浓度的有毒元素砷（As）。为了阐明水稻种植过程中影响土壤溶液中砷溶解的因素，2005年和2006年在温室中的六种水稻土中种植水稻（Oryza sativa L. “Selenio”）直至成熟。测定了土壤溶液中锰、铁、砷、磷和硅酸的浓度以及稻草和精米中的砷浓度。土壤溶液中铁和砷的浓度之间存在密切关系，这表明溶解砷的主要部分源自还原态铁（氢）氧化物。然而，除了导致土壤中砷溶解的因素外，其他因素也影响水稻对砷的吸收。土壤溶液中天然硅酸对砷吸收的抑制作用得到了明确体现。这意味着植物有效硅含量高的土壤会导致植物砷含量低，并且向土壤中施用硅可能会降低水稻的砷含量。
