摘要
为研究三元复合调理剂(石灰石+硅藻土+硫酸铁,LDF)对稻田土壤Cd和As赋存形态及水稻糙米Cd和As累积的影响,开展水稻盆栽试验.LDF按质量比设置7个施用水平(0、0.5、1.0、2.0、4.0、8.0和16.0 g·kg^(-1)),种植2种水稻(黄华占和T优272).结果表明:①施用LDF分别提高黄华占和T优272根际土壤pH 0.01~0.42和0.11~0.54单位,降低土壤交换态Cd含量11.1%~61.1%和26.5%~52.9%,同时降低土壤交换态As含量8.2%~60.0%和5.6%~49.9%;②施用LDF能促进Cd、As向难溶态的转变,尽管2种水稻根际变化趋势不一致,但都可降低土壤Cd的酸可提取态占比,而增大铁锰结合态、有机结合态和残渣态占比,同时可降低As的交换态占比,而增大钙结合态占比;③LDF的施用能降低根表铁膜中Cd、As和Fe含量而增大Mn含量,Mn的最大增幅可达124.2%;④LDF施用下2种水稻糙米中Cd含量最大降低64.6%和65.9%,总As含量最大降低37.0%和42.5%,对无机As含量影响不显著.LDF施用量在2~16 g·kg^(-1)水平时,T优272糙米中Cd和无机As含量同时低于0.2 mg·kg^(-1),而黄华占仅在16 g·kg^(-1)水平时,糙米中Cd和无机As含量同时低于0.2 mg·kg^(-1).在实际农业生产过程中,可根据土壤Cd和As污染程度和水稻品种确定LDF施用量.
A pot experiment was conducted to identify the effect of a tribasic amendment(limestone+diatomite+ferric sulfate,LDF)on chemical fractions of Cd and As in paddy soils and their accumulation in brown rice.LDF was set to seven levels(0,0.5,1.0,2.0,4.0,8.0,and 16.0 g·kg^(-1))based on the quality ratio,and two genotypes of rice were planted(Huanghuazhan and T-you 272).The results show that:①The application of LDF increased the rhizosphere soil pH of two varieties of rice,Huanghuazhan and T-you 272,by 0.01-0.42 and 0.11-0.54,respectively,and decreased the concentrations of EX-Cd by 11.1%-61.1%and 26.5%-52.9%,respectively,and the concentrations of EX-As by 8.2%-60.0%and 5.6%-49.9%,respectively.②Application of LDF promoted the transformation of soil Cd and As from soluble to insoluble forms.Although the trends of the rhizosphere soils of the two rice varieties were not consistent,the application of LDF could decrease the proportion of EX-Cd and increase the proportion of Fe/Mn-Cd,Org-Cd,and O-Cd,which was accompanied by the reduction of the proportion of EX-As and an increase in the proportion of Ca-As.③The concentrations of Cd,As,and Fe in the iron plaque decreased by applying LDF,while the concentration of Mn increased,and the maximum increase of Mn could reach 124.2%.④Application of LDF decreased the concentrations of Cd in brown rice of the two varieties of rice by 64.6%and 65.9%,respectively,and decreased that of As by 37.0%and 42.5%,respectively.The effect on the concentrations of inorganic As was not significant.When the application amount of LDF was 2-16 g·kg^(-1),the concentrations of Cd and inorganic As in T-you 272 brown rice were both under 0.2 mg·kg^(-1),and when the application amount was 16 g·kg^(-1),the concentrations of Cd and inorganic As in Huanghuazhan brown rice were both under 0.2 mg·kg^(-1).In actual agricultural production,the application amount of LDF can be adjusted according to the soil pollution levels and the rice varieties.
作者
蒋毅
刘雅
辜娇峰
杨世童
曾雄
王轩宁
周航
廖柏寒
JIANG Yi;LIU Ya;GU Jiao-feng;YANG Shi-tong;ZENG Xiong;WANG Xuan-ning;ZHOU Hang;LIAO Bo-han(College of Environment Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China;Hunan Engineering Laboratory for Control of Rice Quality and Safety,Changsha 410004,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2021年第1期378-385,共8页
Environmental Science
基金
国家自然科学基金项目(41907126)
湖南省自然科学基金项目(2018JJ3880,2018JJ3881)
长沙市科技计划项目(kq1901138)。
关键词
镉
砷
糙米
三元复合调理剂
土壤
赋存形态
cadmium
arsenic
brown rice
tribasic amendment
soil
chemical fractions
