摘要
[目的]本文旨在研究重金属污染土壤施用生物质炭后对土壤有机碳稳定性的影响,为环境污染修复条件下土壤有机碳库的科学管理提供参考。[方法]以苏南地区长期Cd/Pb污染和邻近未污染水稻土为研究对象,采集对照无污染土壤(P0)、低污染土壤(P1)和高污染土壤(P2)3种土壤,每种土壤分别设置施用量为0(C0)、10 g·kg^-1(C1)和20 g·kg^-1(C2)的玉米秸秆生物质炭处理,进行为期60 d的恒温恒湿室内培养试验,对比分析施用生物质炭对不同程度重金属污染水稻土中CO2-C释放动态、总有机碳和活性碳库含量和激发效应的影响。[结果]添加生物质炭能够显著增加不同程度重金属污染水稻土CO2排放,其中未污染和低污染土壤施加生物质炭后其CO2的释放速率及累积矿化量显著高于高污染土壤。相比于污染土壤,施加生物质炭对未污染土壤易氧化态碳含量的增加影响更显著;P1土壤低炭和高炭处理分别比原土微生物量碳含量增加23.1%和27.1%,P2土壤增加49.7%和41.7%;P1土壤低炭和高炭处理颗粒态有机碳含量分别比对照增加66.9%和200.2%,P2土壤增加22.2%和45.8%;施炭处理可显著降低土壤中的可溶性有机碳含量。施用生物质炭对各处理土壤产生负激发效应,且在低污染土壤中表现最为显著;生物质炭抑制土壤本底碳的矿化,促进土壤原有有机碳的稳定性。[结论]施用生物质炭可提高重金属污染水稻土中有机碳的累积量,增加土壤中活性碳库的组分,抑制土壤中原有有机碳的矿化分解,存在显著的负激发效应。
[Objectives]Biochar has great potential in heavy metal-contaminated soil remediation and in soil carbon sequestration.The objective of this study was to investigate the effect of biochar addition on the stability of soil organic carbon in heavy metal-contaminated paddy soil,which can provide a scientific base for the management of heavy metal polluted soil remediation.[Methods]The soils used in this study were collected from the south urban areas of Jiangsu Province.They were polluted by Cd and Pb for a long period of time except the control soil collected near the polluted field.Three levels of contaminated soils were selected with the non-polluted soil as a control(P0),medium level polluted soil(P1)and high level polluted soil(P2).The biochar used in this study was derived from maize straw.For each soil,biochar was applied at rate of 0(C0),10 g·kg^-1(C1)and 20 g·kg^-1(C2).A 60-day incubation experiment was conducted to measure soil respiration rate(CO2-C emission).The total and active organic carbon content were analyzed by the end of incubation and theirδ13C values were quantified to access the priming effect.[Results]Biochar generally promoted the soil respiration rate of the different heavy metal-contaminated soils;and the soil respiration rates following biochar addition in P0 and P1 are significantly greater than that of P2.Biochar had greater impact on the content of oxidized organic carbon in P0 than that in P2.Under P1,biochar increased the content of soil microbial biomass carbon by 23.1%and 27.1%respectively for application rate of C1 and C2,and the content of particular organic carbon increased by 66.9%and 200.2%.Under P2,biochar increased soil microbial biomass carbon content by 49.7%and 41.7%,and the particular organic carbon content increased by 22.2%and 45.8%.Biochar addition decreased the content of dissolved organic carbon significantly.A negative priming effect was observed following biochar addition,especially in P1.This suggested that biochar inhibited the mineralization of soil organic c
作者
赵熙君
冷雪梅
张旭辉
应多
刘晓雨
郑聚锋
卞荣军
李恋卿
潘根兴
ZHAO Xijun;LENG Xuemei;ZHANG Xuhui;YING Duo;LIU Xiaoyu;ZHENG Jufeng;BIAN Rongjun;LI Lianqing;PAN Genxing(Institute of Resource,Ecosystem and Environment of Agriculture,Nanjing Agricultural University,Nanjing 210095,China)
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2020年第3期468-476,共9页
Journal of Nanjing Agricultural University
基金
国家自然科学基金项目(41471193,41501310)
江苏高校品牌专业建设工程资助项目(PPZY2015A061)。
关键词
生物质炭
重金属污染
水稻土
有机碳矿化
激发效应
biochar
heavy metal pollution
paddy soil
organic carbon mineralization
priming effect
