氯仿熏蒸对紫色土农田土壤有机碳矿化的影响  

Effects of chloroform fumigation on soil organic carbon mineralization in purple soil farmland

作　　者：马晗 王小国[1] MA Han;WANG Xiaoguo(Key Laboratory of Mountain Surface Growth and Ecological Regulation,Chinese Academy of Sciences/Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院山地表生过程与生态调控重点实验室/中国科学院水利部成都山地灾害与环境研究所,成都610041 [2]中国科学院大学,北京100049

出　　处：《中国生态农业学报（中英文）》2022年第11期1819-1826,共8页Chinese Journal of Eco-Agriculture

基　　金：国家自然科学基金项目(42171067)资助。

摘　　要：土壤有机碳的矿化主要是土壤有机碳在微生物作用下发生分解的过程,是土壤有机碳损失的重要途径,氯仿具有极强的灭菌作用,不同微生物对氯仿的敏感性不同,改变熏蒸时长可以改变土壤微生物生物量。为探究紫色土农田土壤微生物生物量对有机碳矿化的影响,选择长期施用猪粪肥处理小区的土壤,通过不同时长的氯仿熏蒸,设置不同土壤微生物生物量的室内培养试验,观测不同处理的CO_(2)排放速率及通量变化,试验包括熏蒸24 h(C24)、2.5 h(C2.5)、1.5 h(C1.5)、1 h(C1)与未熏蒸对照组(CK)5种处理。结果表明,不同处理间土壤CO_(2)排放速率变化趋势一致,培养0~7 d内,土壤CO_(2)排放速率快速增长至最大值后下降,不同处理CO_(2)排放速率最大值依次为C2.5>C24>C1.5>C1>CK,处理间存在显著差异(P<0.05);与CK相比,熏蒸处理的增幅分别为309.01%、182.00%、73.85%和30.45%。7~53 d内,CO_(2)排放速率缓慢增长后缓慢下降,32~53 d熏蒸处理CO_(2)排放速率略低于CK,C24、C2.5、C1.5、C1和CK处理7~53 d内CO_(2)排放速率均值分别为6.01±0.43μg∙g^(−1)∙h^(−1)、5.94±0.29μg∙g^(−1)∙h^(−1)、6.07±0.59μg∙g^(−1)∙h^(−1)、5.78±0.49μg∙g^(−1)∙h^(−1)和6.23±0.13μg∙g^(−1)∙h^(−1),处理间差异不显著。本研究结果支持了土壤有机碳矿化的“调节门假说”,该假说认为土壤有机碳的矿化与微生物生物量大小、群落组成及活性无关。In recent decades,mineralization of soil organic carbon has gradually become a focus due to greenhouse gas(GHG)emissions.The mineralization of soil organic carbon is mainly the decomposition of soil organic carbon under the action of microorganisms,which is an important pathway for soil organic carbon loss.Chloroform has strong sterilization power,and different microorganisms have different sensitivities to it.Furthermore,the soil microbial biomass and community composition can be changed by different fumigation durations.To explore the limiting factors of soil organic carbon mineralization in purple soil farmland,soils from plots with long-term application of pig manure treatment were selected for this laboratory incubation study.The effect of different soil microbial biomasses on soil organic carbon mineralization was investigated through varying the chloroform fumigation time and observing the changes in CO_(2) emission rate under different treatments.The experiment included five treatments:fumigation for 24 h(C24),2.5 h(C2.5),1.5 h(C1.5),and 1 h(C1);and an unfumigated control(CK).The treatment not only changed the soil microbial biomass,but also greatly changed the soil microorganism community composition,which further verified the Regulation Gate hypothesis.The results showed that after fumigation,the soil microbial residues released microbial biomass carbon and the remaining microorganisms rapidly utilized this carbon source.Due to the availability of this new carbon source,the soil CO_(2) emission rate increased rapidly.The variation trend in the soil CO_(2) emission rate among different treatments was consistent.Due to the microbial residue carbon source,the CO_(2) emission rate of fumigation treatment was higher than that of CK within 7 days of incubation,increasing rapidly to a maximum and then decreasing to a level comparable to the initial level.The order of the maximum values of the soil CO_(2) emission rate among different treatments was C2.5>C24>C1.5>C1>CK.Compared with CK,the increases were 309.01

关 键 词：紫色土 熏蒸 土壤微生物 土壤有机碳矿化 

分 类 号：X51[环境科学与工程—环境工程] X53