不同水分管理下施用尿素对土壤镉污染钝化修复效应及微生物结构与分布影响  

Effects of urea on in-situ remediation of Cd polluted paddy soil and the structure and distribution of soil microbes under different water management

作　　者：黄荣 徐应明 黄青青 秦旭 赵立杰 梁学峰 刘艺芸 HUANG Rong XU Yingming HUANG Qingqing QIN Xu ZHAO Lijie(Innovative Team of Remediation for Heavy Metal Contaminated Farmland, Ago-Environmental Protection Institute,Ministry of Agriculture, Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture/Tianjin Key Laboratory of Agro-environment and Food Safety, Tianjin, 300191, Chin)

机构地区：[1]农业部环境保护科研监测所农田童金属污染修复创新团队、农业部产地环境污染防控重点实验室、天津市农业环境与农产品安全重点实验室,天津300191

出　　处：《环境化学》2018年第3期523-533,共11页Environmental Chemistry

基　　金：中国农业科学院农业科技创新工程项目(2016-cxgc-xym); 农业部农业生态环境保护项目(2016-sthj-xym); 国家现代农业产业技术体系(CARS-03); 天津市科技支撑计划项目(14ZCZDSF00004); 天津市农业科技成果转化与推广项目(201404100)资助

摘　　要：通过水稻盆栽实验,开展了全生育期淹水灌溉和湿润灌溉二种水分管理模式条件下,施用不同量尿素对土壤镉污染钝化修复效应及微生物结构与分布影响研究.结果表明,海泡石钝化修复下,淹水灌溉和湿润灌溉处理时,施用不同量尿素对土壤中0.025 mol·L-1HCl浸提态Cd含量无明显影响;但二乙基三胺五乙酸浸提态Cd含量均显著性降低.与海泡石单一钝化处理相比,淹水灌溉和湿润灌溉下海泡石钝化处理时,施用不同量尿素可使水稻根系铁氧化物胶膜中的Fe含量分别降低39.61%—55.59%和22.51%—53.63%.淹水管理下施用尿素对水稻根膜吸附土壤中Cd有抑制作用,而湿润管理下施用尿素对水稻根膜吸附土壤中Cd有激活作用.淹水灌溉和湿润灌溉下海泡石钝化处理时,施用不同量尿素可使水稻根系中的Cd含量分别增加36.11%—71.30%和58.20%—89.42%,水稻根系中还原型谷胱甘肽活性则分别降低30.82%—41.97%和13.47%—62.36%.淹水灌溉下海泡石钝化处理时,施用不同量尿素可以降低水稻根系中非蛋白巯基化合物含量,降幅可达13.02%—29.54%;但在湿润灌溉下海泡石钝化处理时并无明显影响.与海泡石单一钝化处理相比,淹水灌溉下钝化处理时,施用低量尿素和中量尿素时可使糙米中Cd含量分别增加28.89%和8.89%,而施用高量尿素时则使糙米中Cd含量降低22.22%;湿润灌溉下钝化处理时,施用低量尿素、中量尿素和高量尿素时糙米Cd含量与海泡石单一处理间并无明显差异.土壤微生物的非加权组平均法和主成分分析表明,实验条件下的钝化处理不会对土壤中微生物的结构与分布产生明显影响.Pot experiments were conducted to investigate the effects of urea on in-situ remediation of Cd polluted paddy soil under different water management. The experimental results showed that with flooded and non-flooded water management,urea addition did not change the exchangeable Cd concentration by 0.025 mol·L-1 HCl significantly under the immobilization remediation of sepiolite,but it decreased the exchangeable Cd content by diethylenetriaminepentaacetic acid leaching significantly. Compared with the immobilization remediation of sepiolite,the Fe concentration of dithionite-citrate-bicarbonate leach liquor after urea addition was decreased by 39. 61%—55. 59%and 22.51%—53.63% under flooded and non-flooded management,respectively. Urea had a positive effect on soil Cd adsorption by root iron plaque under the flooded management,but have a negative effect under the non-flooded management. The Cd concentration of root was increased by 36.11%—71. 30% and 58. 20%—89. 42% in the two water management, and the reduced glutathione concentration was decreased by 30. 82%—41. 97% and 13. 47%—62. 36%,respectively. The nonprotein thiol concentration was decreased by 13. 02%—29. 54% after adding urea under flooded management,but had no significant change in non-flooded management. Under flooded management,adding low and medium dosage urea increased the Cd concentration in brown rice, but the concentration decreased after adding high dosage urea. The Cd concentration did not change significantly after adding different dosage urea under non-flooded water management. Unweighted pair-group method with arithmetic means and principal component analysis were used to analyze the soil microbial biomass. The results showed that immobilization remediation had no obvious influence on soil microbial structure and distribution under different experimental conditions.

关 键 词：土壤 镉污染 海泡石 钝化 尿素 水分管理 

分 类 号：X172[环境科学与工程—环境科学] X53