Kikuchi Tetsuro, Okazaki Masanori, Kimura Sonoko Dorothea, Motobayashi Takashi, Baasansuren Jamsranjav, Hattori Takayuki, Abe Toshio
Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
J Hazard Mater. 2008 Jun 15;154(1-3):294-9. doi: 10.1016/j.jhazmat.2007.10.025. Epub 2007 Oct 13.
The objective of this study is to assess the applicability of a commercial magnesium oxide (MgO) and a composite material containing MgO and natural minerals ('MgO-SH-A') as the soil amendments for suppression of cadmium (Cd) uptake and accumulation into rice grains. A cultivation experiment of rice plants (Oryza sativa L. cv. Kinuhikari) was conducted in an actual Cd-contaminated alluvial paddy field to evaluate the effectiveness of these materials. The 'plant available' fractions of Cd in the paddy soil significantly decreased by application of commercial MgO at 2250 kg ha(-1) or MgO-SH-A at 4500 kg ha(-1). These decreases would be primarily attributed to the increase in soil pH due to applications of the MgO materials because these soil Cd fractions were significantly negatively correlated with the soil pH. Even under a suppressive condition for Cd uptake by rice plants, i.e., continuous flooding of the paddy field around the heading stage, applications of these materials further reduced Cd concentration in brown rice as compared to that from the control. It was concluded that the two MgO materials examined would be effective in preventing Cd contamination of rice grains grown in Cd-polluted paddy fields.
本研究的目的是评估一种商用氧化镁（MgO）以及一种包含MgO和天然矿物质的复合材料（“MgO-SH-A”）作为土壤改良剂用于抑制水稻籽粒对镉（Cd）的吸收和积累的适用性。在实际受镉污染的冲积稻田中进行了水稻植株（Oryza sativa L. cv. Kinuhikari）的栽培试验，以评估这些材料的有效性。在稻田土壤中，施用2250 kg ha(-1)的商用MgO或4500 kg ha(-1)的MgO-SH-A后，土壤中“植物有效态”镉组分显著降低。这些降低主要归因于施用MgO材料导致土壤pH值升高，因为这些土壤镉组分与土壤pH值显著负相关。即使在抑制水稻植株吸收镉的条件下，即在抽穗期前后稻田持续淹水的情况下，与对照相比，施用这些材料进一步降低了糙米中的镉浓度。得出的结论是，所研究的两种MgO材料对于防止在镉污染稻田中种植的水稻籽粒受到镉污染是有效的。
