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通过水稻盆栽试验,研究了施用钙镁磷肥对Cd污染稻田中Ca、Mg、Cd生物有效性的影响和种植水稻(湘晚籼12号、威优46号)后水稻各部位Ca、Mg、Cd含量的差异.结果表明,施用钙镁磷肥能显著提升土壤pH值,降低土壤TCLP提取态Cd含量,且降低效果随着水稻生育期的延长逐渐增强.与对照相比,施用0.8 g·kg-1的钙镁磷肥,使湘晚籼12号种植土壤和威优46号种植土壤TCLP提取态Cd含量在熟化期、灌浆期、分蘖期、成熟期分别下降了12.7%、15.6%、21.5%、61.9%和12.7%、72.6%、42.1%、59.7%.施用钙镁磷肥能显著增加水稻种植土壤中TCLP提取态Ca、Mg含量,降低TCLP提取态Cd含量,同时显著增加水稻各生育期各部位Ca、Mg含量并降低其Cd含量,水稻各部位中Ca、Mg含量与Cd含量均呈现负相关关系,表明外源Ca和Mg的加入对水稻累积Cd产生了拮抗作用.施用钙镁磷肥能显著降低水稻糙米中Cd含量并提高水稻产量.与对照相比,施用0.2~0.8 g·kg-1的钙镁磷肥,水稻湘晚籼12号和威优46号糙米中Cd含量分别下降了36.8%~52.6%和53.3%~75.6%.威优46号比湘晚籼12号更易将土壤Cd向水稻籽粒中转运.
The effects of applying Ca, Mg and P fertilizers on the bioavailability of Ca, Mg and Cd in paddy soils contaminated by cadmium were studied through rice pot experiments. The effects of Ca, Mg, Cd on the bioavailability of Ca, Mg and Cd in paddy soils after planting rice (Xiangshenshan 12 and Weiyou 46) The results showed that the application of Ca, Mg and P fertilizers could significantly increase the pH of soil and decrease the content of Cd in soil TCLP extract, and the decreasing effect increased with the extension of rice growth period.Compared with the control, application of 0.8 g · kg- 1, the content of Cd in TCLP extracted soil of Xiangwanxian 12 and that of Weiyou 46 decreased by 12.7%, 15.6% and 21.5% respectively at the ripening, filling, tillering and maturing stages, 61.9% and 12.7%, 72.6%, 42.1% and 59.7%, respectively. Application of Ca, Mg and P fertilizers could significantly increase the contents of Ca and Mg in TCLP-extracted soil and the content of Cd in TCLP-extracted soil, Ca and Mg contents and the content of Cd in rice were negatively correlated with each other, and there was a negative correlation between the content of Ca and Mg and the content of Cd in different parts of rice, indicating that addition of exogenous Ca and Mg antagonized the accumulation of Cd in rice. Reduce Cd content in rice brown rice and increase rice yield. Compared with the control, the content of Cd decreased by 36.8% -52.2% and 53.3% -75.6%, respectively, in the rice with the dosage of 0.2-0.8 g · kg-1 for Xiangshenxian 12 and Weiyou 46 in rice. 46 is more susceptible to transporting Cd from the soil to rice grains than the late Xiangxian 12.