地下滴灌土壤水分分布对设施种植农田甲烷通量的影响  

Effect of Soil Moisture Distribution under Subsurface Drip Irrigation on Soil CH_(4) Flux in Facility Farmland

作　　者：王京伟 何秋琴[1] 宋晓伟 牛文全 WANG Jingwei;HE Qiuqin;SONG Xiaowei;NIU Wenquan(College of Resources and Environment,Shanxi University of Finance and Economics,Taiyuan 030006,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,China;Institute of Soil and Water Conservation,CAS&MWR,Yangling 712100,China)

机构地区：[1]山西财经大学资源环境学院,山西太原030006 [2]西北农林科技大学水土保持研究所,陕西杨凌712100 [3]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《环境科学研究》2023年第7期1368-1378,共11页Research of Environmental Sciences

基　　金：山西省基础研究计划项目(No.20210302123482);国家自然科学基金项目(No.51679205)。

摘　　要：为优化设施土壤水分管理、挖掘固碳减排潜力,该文采用田间控制性试验,以设施农业中普遍栽培的番茄为对象,研究了不同滴灌管埋深(0、10、20、30 cm,依次记为DI、SDI10、SDI20、SDI30)土壤水分状况对土壤甲烷(CH_(4))通量变化的影响及其驱动机理.结果表明:①不同滴灌管埋深的番茄土壤CH_(4)通量呈波动变化,但总体为吸收效应.“植株+土壤”条件下,SDI20、SDI30的CH4累积吸收量分别为DI的7.12、4.11倍(P<0.05);“根系+土壤”条件下,SDI20、SDI30的CH_(4)累积吸收量分别较DI增加26.02%、89.43%(P<0.05).滴灌管埋深增加造成的土壤水分分布和水分均匀度差异对土壤CH4吸收量具显著调节作用.②滴灌管埋深显著影响根区土壤理化特性,如SDI10、SDI20、SDI30的土壤NO_(3)^(-)-N含量分别为DI的2.21、2.28、1.54倍(P<0.05),SDI10、SDI20的0~20 cm土壤充气孔隙度较DI增加14.45%、33.27%(P<0.05);滴灌管埋深增加造成的土壤理化特性改变明显提高了番茄根系分叉数,增强了根-土互作,形成了利于CH4氧化的条件,如SDI20、SDI30显著增加了CH4氧化基因K10944(pmoA-amoA)、K10945(pmoB-amoB)、K10946(pmoC-amoC)的拷贝数,而这些基因拷贝数与CH_(4)累积吸收量、根系分叉数均呈显著正相关.③CH4累积吸收量变化的路径分析表明,CH_(4)氧化基因拷贝数变化是影响CH4累积吸收量的关键因素,而滴灌管埋深变化造成的根系分叉数(R=0.77)与NH_(4)^(+)-N含量(R=0.42)的差异对CH_(4)氧化基因具有显著的直接调节效应.总体上,SDI20、SDI30通过提高根系分叉数、CH_(4)氧化基因拷贝数和果实膨大期叶片鲜质量,增强了“地面植株-根-土”交互作用,促进了土壤CH4吸收;DI、SDI10相对减弱了“地面植株-根-土”交互作用,抑制了土壤CH_(4)吸收.研究显示,滴灌管埋深通过影响土壤水分分布状况和植株生长差异调节根-土互作以及土壤CH4累积吸收量.In order to optimize soil moisture management and tap into the potential for carbon sequestration and emission reduction,a field control experiment of tomato cultivation was conducted to study the variability of soil CH_(4) flux in crop root zone soil caused by soil moisture at different burial depths of drip irrigation pipe(0,10,20,30 cm,i e.DI,SDI10,SDI20,SDI30),and its driving mechanism was analyzed.The results are showed that:(1)The CH_(4) flux in tomato soil with different burial depth of drip irrigation pipe showed fluctuating but overall absorption effects.When the‘plant+soil’was used as the whole monitoring,it was found that the CH_(4) accumulative absorption of SDI20 and SDI30 was 7.12 and 4.11 times(P<0.05)that of DI,respectively.Taking‘root+soil’as the monitoring object,the CH_(4) accumulative absorption of SDI10 and SDI20 increased by 28.81% and 26.02% compared to that of DI,respectively(P<0.05).Therefore,the difference of soil moisture distribution and uniformity caused by the increase of buried depth of drip irrigation pipe had a significant regulation effect on soil CH4 absorption.(2)The buried depth of drip irrigation pipe significantly affected the physical and chemical properties of soil in the root zone.For example,the soil NO_(3)^(−)-N content in SDI10,SDI20 and SDI30 was 2.21,2.28 and 1.54 times(P<0.05)that of DI,respectively.The soil aeration porosity of SDI10 and SDI20 at 0-20 cm significantly increased by 14.45% and 33.27%(P<0.05)compared to DI,respectively.The changes of soil physicochemical properties caused by the increase of the burial depth of drip irrigation pipe significantly increased the root forks number of tomato,enhanced‘root-soil’interaction,and formed favorable conditions for CH_(4) oxidation.For example,SDI20 and SDI30 significantly increased the CH_(4) oxidation genes copy number of K10944(pmoA-amoA),K10945(pmoB-amoB)and K10946(pmoC-amoC),which was significantly positively correlated with the CH_(4) accumulative absorption and the root forks number of tomato.(

关 键 词：土壤水分分布 CH_(4)通量 根区土壤 根系分叉数 CH_(4)氧化基因 

分 类 号：X506[环境科学与工程—环境工程]