水稻镉累积综合管控措施的大面积应用效果及其稳定性

Effects and Stability of Comprehensive Measures for Mitigating Rice Cadmium Accumulation in Large Fields

研究在中方县泸阳镇轻中度镉污染稻田连续5 a开展修复治理工程,采取了石灰质复合材料调酸、镉砷同步钝化、增施有机肥和优化田间水分管理等措施,并对综合管控措施的大面积应用效果及稳定性进行了评价。结果表明,综合管控措施实施后,示范区稻米平均镉含量显著降低且稻米镉达标率在第2年之后持续稳定在88.6%以上;稻米砷、铅、汞的达标率均稳定维持在97.28%以上;土壤pH值显著提高了0.61~1.28;土壤有机质含量略有降低,降幅为1.62%~13.78%;有效态镉含量显著降低,降幅为41.41%~51.17%;稻米镉富集系数与土壤pH值呈极显著负相关,表明示范区土壤pH值提高是稻米镉含量降低的重要原因。

Restoration for cadmium(Cd)accumulation was implemented in the lightly to moderately Cd-polluted paddy fields in Luyang Town,Zhongfang County for five consecutive years.The specific measures included regulating acids with lime-based composite materials,simultaneously passivating Cd and arsenic(As),applying manure,and optimizing water management in the field.The results showed that after the implementation of comprehensive control measures,the average Cd content in rice decreased and the Cd compliance rate remained stable at above 88.6%after the second year.Moreover,the compliance rates of As,lead,and mercury in rice all remained stable at above 97.28%.The implementation of the measures increased soil pH by 0.61-1.28,decreased the soil organic matter by 1.62%-13.78%,and reduced available Cd in soil by 41.41%-51.17%.The Cd enrichment factor in rice had a significantly negative correlation with soil pH,which indicated that the increase in soil pH was an important reason for the reduction in the Cd content in rice.