Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Int J Environ Res Public Health. 2022 Sep 25;19(19):12128. doi: 10.3390/ijerph191912128.
Straw return can improve soil quality and change the mobility and bioavailability of pollutants in soil. Elevated cadmium (Cd) contents in farmland soils were often reported. However, the impacts of straw-derived dissolved organic matter (DOM) on Cd speciation in soil remain poorly understood. In this study, the effects of straw return and moisture condition on temporal changes of DOM composition and Cd speciation in farmland soils were explored through a laboratory incubation experiment. The humified components of DOM were negatively correlated with exchangeable, carbonate-bound, and Fe-Mn oxide-bound Cd ( < 0.01), while its protein-like component was negatively correlated with residual Cd ( < 0.01). It was found that selected fluorescence parameters could be used to predict temporal changes of Cd geochemical fractions. Straw addition led to increases in soil DOM content during the first three days of the incubation. Flooding should be avoided in the first three days following the straw application to reduce the risk of DOM-facilitated Cd mobilization.
秸秆还田可以改善土壤质量，并改变土壤中污染物的迁移性和生物可利用性。农田土壤中镉（Cd）含量升高的情况经常被报道。然而，秸秆衍生的溶解有机物质（DOM）对土壤中 Cd 形态的影响仍知之甚少。在这项研究中，通过实验室培养实验，探讨了秸秆还田和水分条件对农田土壤中 DOM 组成和 Cd 形态随时间变化的影响。DOM 的腐殖质成分与可交换态、碳酸盐结合态和铁锰氧化物结合态 Cd 呈负相关（<0.01），而其蛋白样成分与残留态 Cd 呈负相关（<0.01）。研究发现，一些荧光参数可以用来预测 Cd 地球化学形态的时间变化。秸秆添加在培养的前三天导致土壤 DOM 含量增加。在秸秆施用后的头三天应避免淹水，以降低 DOM 促进 Cd 迁移的风险。
Zotero 插件
