菜籽饼施加对镉-铜污染土壤中重金属形态转化及其植物有效性的影响

选择菜籽饼作为有机物料，模拟水田条件，研究菜籽饼施用后重金属污染土壤中镉-铜的赋存形态的变化及其有效性的影响。结果表明，菜籽饼施加后，土壤pH波动在0.5内，变化较小。但在一定程度促进土壤中镉、铜由弱酸提取态向可还原态转化，残渣态占比变化均较小。经培养一定时间，植物有效态DTPA-Cd由1.26±0.03下降至0.69±0.03，下降幅度约为45.2%，DTPA-Cu由82.9±0.09下降至48.7±0.09，最大下降幅度约为41.3%，下降较为明显。同时，土壤溶液中可溶性碳（DOC）和可溶性氮（DON）的含量显著增加，分别增加约4.14倍和6.48倍，因此，菜籽饼应用于重金属污染水稻土改良，可以间接降低水稻中重金属的含量。

Effects of rapeseed cake on cadmium and copper forms and its phytoavailability in heavy metals contaminated paddy soil

Soil incubation experiments were conducted in simulated paddy soils to investigate the effects of rapeseed cake (RSC) on cadmium and copper forms and their phytoavailability in heavy-metal-contaminated soil.The results showed that the soil pH changed at a range of 0.5, but the application of RSC increased the perception of oxidizable-Cd and FeMn-Cu while reducing the content of weak acid-Cu and weak acid-Cd.Meanwhile, DTPA-Cd decreased from 1.26±0.03 to 0.69±0.03 with a maximum decline of about 45.2% and DTPA-Cu decreased from 82.9±0.09 to 48.7±0.09, with a maximum decline of about 41.3%.Moreover, the concentrations of DOC and DON in the treated soils increased by about 4.14 and 6.48 times, respectively, compared to the control experiments.Application of RSC to the heavy-metal-contaminated paddy soil could indirectly reduce the metal uptakes of rice.