Elevated CO_(2) increases soil redox potential by promoting root radial oxygen loss in paddy field  

作　　者：Jie Li Han Zhang Wenyi Xie Cheng Liu Xiaoyu Liu Xuhui Zhang Lianqing Li Genxing Pan 

机构地区：[1]Institute of Resource,Ecosystem and Environment of Agriculture,Nanjing Agricultural University,Nanjing 210095,China [2]College of Agriculture,Nanjing Agricultural University,Nanjing 210095,China

出　　处：《Journal of Environmental Sciences》2024年第2期11-20,共10页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.42277328);the Sino-German Mobility Program (No.M-0105)。

摘　　要：Soil redox potential(Eh)plays an important role in the biogeochemical cycling of soil nutrients.Whereas its effect soil process and nutrients'availability under elevated atmospheric CO_(2) concentration and warming has seldom been investigated.Thus,in this study,a field experiment was used to elucidate the effect of elevated CO_(2) concentration and warming on soil Eh,redox-sensitive elements and root radial oxygen loss(ROL).We hypothesized elevated CO_(2) and warming could alter soil Eh by promoting or inhibiting ROL.We found that soil Eh in the rhizosphere was significantly higher than that of non-rhizosphere.Elevated CO_(2) enhanced soil Eh by 11.5%,which corresponded to a significant decrease in soil Fe^(2+)and Mn^(2+)concentration.Under elevated CO_(2),the concentration of Fe^(2+)and Mn^(2+)decreased by 14.7%and 13.7%,respectively.We also found that elevated CO_(2) altered rice root aerenchyma structure and promoted rice root ROL.Under elevated CO_(2),rice root ROL increased by 79.5%and 112.2%for Yangdao 6 and Changyou 5,respectively.Warming had no effect on soil Eh and rice root ROL.While warming increased the concentration of Mn^(2+)and SO_(4)^(2-)by 4.9%and 19.3%,respectively.There was a significant interaction between elevated CO_(2) and warming on Fe^(2+)and Mn^(2+).Under elevated CO_(2),warming had no effect on the concentration of Fe^(2+)but decreased Mn^(2+)concentration significantly.Our study demonstrated that elevated atmospheric CO_(2) in the future could increase soil Eh by promoting rice root ROL,which will alter some soil nutrients'availability,such as Fe^(2+)and Mn^(2+).

关 键 词：Atmospheric CO_(2)enrichment Global warming Soil redox potential FACE Rice root aerenchyma 

分 类 号：X144[环境科学与工程—环境科学]