生态环境学报2024，Vol.33Issue(7)：1096-1106,11.DOI:10.16258/j.cnki.1674-5906.2024.07.011
紫云英长期还田对稻田土壤DOM和Cd形态影响研究
Effects of Long-term Returning of Astragalus sinicus L.on Content and Forms of DOM and Cd in Paddy Soil
摘要
Abstract
Long-term planting and incorporation of green manuring Chinese milk vetches may significantly enhance the content of soil organic matter(SOM)and dissolved organic matter(DOM),thus influencing the adsorption behavior and speciation of cadmium(Cd)in soils.Understanding the characteristics of Cd in the soil layers at different depths is important for spreading the planting of Chinese milk vetches.This study was conducted at long-term experimental sites in Yujiang District(YJ),Nanchang County(NC),and Fengcheng City(FC)of Jiangxi Province,where chemical fertilizer and Chinese milk vetch were employed together(F+M),as well as chemical fertilizer alone.Dissolved organic carbon(DOC),SOM,3D-EEMs,and Cd speciation in soils at different depths were investigated to determine the effects of Chinese milk vetch planting on DOM composition and Cd speciation in different soil layers.The results demonstrated that the SOM content in the plow layer soil(0‒20 cm)under the F+M treatment at the NC and FC experimental sites was significantly higher than that under the F treatment,with increases of 16.80%and 10.47%,respectively.The bioavailability of Cd in the soils of the F+M treatment was generally higher than that in the soils of the F treatment.The DOM of Chinese milk vetch is primarily transported in the plow layer and middle soil layers(20‒40 cm).Compared with those under the F treatment at the YJ,NC,and FC experimental sites,the DOC content in the plow layer soil under the F+M treatment increased by 17.02%,58.14%,and 33.72%,respectively,and those in the middle layer soil increased by 42.95%,36.67%,and 11.21%,respectively.The application of Chinese milk vetch can reduce the proportion of protein-like components in DOM,while increasing the proportion of humus-like components.In the plow,middle,and deep layers(40‒60 cm)of soils,the average contributions of protein-like components in DOM under the F treatments of the three experimental sites were 7.34%,16.72%,and 23.93%,respectively,which were about 1.26,1.92,and 1.54 times higher than those in the F+M treatment group.Compared with humus-like components,protein-like components showed a higher migration potential to the deep soil layer.Stepwise regression analysis revealed that the proportions of biologically active Cd speciation were negatively correlated with SOM content(r=‒2.170)and tryptophan-like components(r=‒0.760),but positively correlated with the contents of fulvic-like components(r=0.239).The findings of this study suggest that the activation risks of Cd in soils may be posed by changes in SOM and DOM,which could be attributed to long-term planting and the incorporation of green manure Chinese milk vetches in the field.关键词
紫云英/长期还田/水溶性有机物/三维荧光光谱/Cd形态Key words
Astragalus sinicus L./long-term returning/dissolved organic matter/three-dimensional fluorescence spectrum/Cd form分类
资源环境引用本文复制引用
谢杰,陈院华,徐昌旭,杨涛,李建国,董爱琴..紫云英长期还田对稻田土壤DOM和Cd形态影响研究[J].生态环境学报,2024,33(7):1096-1106,11.基金项目
国家自然科学基金项目(22166019) （22166019）
江西省现代农业科研协同创新专项项目(JXXTCXBSJJ202014) （JXXTCXBSJJ202014）
国家重点研发计划项目(2021YFD1700203) （2021YFD1700203）
