玉米秸秆集中深还田对旱地土壤CO_(2)排放特征的影响  

Effects of Corn Straw Concentrated Deep Returning on Soil CO_(2) Emission in Dry Land

作　　者：李晓宇 李金 毕润学 金鑫鑫[1] 范庆锋[1] 邹洪涛[1] LI Xiaoyu;LI Jin;BI Runxue;JIN Xinxin;FAN Qingfeng;ZOU Hongtao(College of Land and Environment,Shenyang Agricultural University/Key Laboratory of Arable Land Conservation(Northeast China),Ministry of Agriculture and Rural Affairs/National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources,Shenyang 110866)

机构地区：[1]沈阳农业大学土地与环境学院/农业农村部东北耕地保育重点实验室/土肥高效利用国家工程研究中心,沈阳110866

出　　处：《土壤》2024年第5期1027-1033,共7页Soils

基　　金：辽宁省应用基础研究计划项目(2022JH2/101300173、2022JH2/101300175)资助。

摘　　要：为探究秸秆深还条件下不同还田量对土壤CO_(2)排放的影响,于田间微区试验设置3个处理,分别为CK(无秸秆还田)、T1(全量还田,10 500 kg/hm^(2))、T2(倍量还田,21 000 kg/hm^(2)),通过LI-8100A土壤碳通量自动测定仪测定土壤CO_(2)排放速率并探究其影响因素。结果表明:(1)秸秆还田提高了CO_(2)排放速率,其中倍量还田与全量还田的CO_(2)累积排放量明显大于无秸秆还田(P<0.01),分别增加了92.53%和61.95%;(2)各处理CO_(2)排放速率在土壤温度为30℃、24%含水量时达到最大,且土壤温度与水分的双因素拟合模型相较于单因素模型更好(R2为0.488~0.583),说明CO_(2)排放速率受土壤温度和水分共同调控;(3)还田100 d后秸秆干物质残留量为25.54%~28.21%,其腐解程度与CO_(2)累积排放量显著正相关,且秸秆腐解后,增加了土壤有机碳、微生物生物量碳、有效磷、速效钾含量,促进了CO_(2)排放。综上所述,土壤CO_(2)排放特征受土壤温度、含水量及其他土壤养分共同作用,且秸秆还田量的增加,能够提升土壤养分,增加CO_(2)排放,促进土壤呼吸。In order to investigate the effects of different amounts of straw returned to the field on soil CO_(2) emission under deep returning condition,an field micro-area experiment was conducted,in which 3 treatments were set,namely CK(no straw returned),T1(full straw returned,10500 kg/hm^(2)),and T2(double straw returned,21000 kg/hm^(2)),soil CO_(2) emission rate was measured by LI-8100A automatic soil carbon flux analyzer,and its influencing factors were investigated.The results showed that:1)Straw returning significantly increased CO_(2) emission rate,with the cumulative CO_(2) emissions from double and full straw returning significantly higher than those from no straw returning(P<0.01),which increased by 92.53%and 61.95%.2)CO_(2) emission rates reached the maximum at 30℃(temperature)and 24%(moisture)under all treatments,and the two-factor fitting model of temperature and moisture was better(R2=0.488–0.583)than the single-factor model,indicating that CO_(2) emission rate was jointly regulated by temperature and moisture.3)The residual dry matter of straw was 25.54%–28.21%after 100 d of field return,and its degree of decomposition was significantly positively correlated with the cumulative CO_(2) emission.The decomposition of straw increased soil organic carbon,microbial biomass carbon,available phosphorus and potassium contents,which promoted CO_(2) emission.In conclusion,the characteristics of soil CO_(2) emissions are affected by soil temperature,moisture and other nutrients,and the increase of straw returned to the field can promote soil nutrients,CO_(2) emission and soil respiration.

关 键 词：秸秆深还田 秸秆还田量 CO_(2)排放 秸秆腐解 

分 类 号：S156[农业科学—土壤学]