石灰配施有机物料对稻麦轮作土壤镉影响研究

Effect of Lime Application with Organic Materials on Soil Cadmium Form in Rice-wheat Rotation Fields

研究旨在开展探究田间试验条件下铜陵市矿区附近镉重度污染农田土壤经石灰和有机物料修复后土壤镉形态的变化,为农田镉污染提供依据。通过水稻和小麦生长田间试验,研究生物有机肥、生物炭、生物肥3种有机物料与石灰配施对稻麦轮作土壤中镉形态变化的影响。研究结果显示:石灰配合有机物料施用后,小麦季土壤酸碱度范围为pH 4.72~5.39,水稻季土壤为pH 6.30~7.25,土壤有效态镉含量显著降低(P<0.05),降幅分别为1.27%~14.71%和17.72%~33.22%,土壤镉的酸溶态等活性形态向残渣态转换,实现了对镉的钝化作用。有机物料配施石灰较单独施用石灰对土壤中镉的钝化效果好,在小麦季生物有机肥配施石灰的钝化效果最好,水稻季则是生物肥配施石灰的钝化效果更好。

The study aims to explore the changes of cadmium form in heavily polluted farmland soil near the mining area of Tongling City after remediation with lime and organic materials under field experiment conditions,and provide a basis for the remediation of cadmium contaminated arable land.The soil cadmium morphological changes by applying bioorganic fertilizer,biochar and biofertilizer combined with lime in ricewheat rotation field were studied respectively.The results showed that after the application of lime with organic materials,the soil pH range of wheat season was pH 4.72-5.39,while that of the rice season was pH 6.30-7.25.The available cadmium content in soil significantly decreased by 1.27%-14.71%and 17.72%-33.22%,respectively(P<0.05).The active forms of soil cadmium,such as acid-soluble state,converted to the residual state,realized the deactivation of cadmium.The passivation effect of lime with organic materials was better than that of lime alone,and the passivation effect of biological organic fertilizer with lime was the best in wheat season.By contrast,biological fertilizer with lime had the best passivation effect in rice season.