Effects of Iron Oxidation on CO2 Emission in Paddy Soils under Dry-wet Alternation Conditions
CHEN Lingyu
LIU Fei
ZHAO Shuangjiao
LI Pengxiang
DING Guanyu
SHI Xu
PENG Qi'an
Abstract：The effects of Fe2+ addition in soil on Fe3+,dissolved organic carbon(DOC)contents and CO2 emission were studied with Xianning rice field (XR,red soil)and Qianjiang rice field (QR,calcareous fluvo-aquic soil) as materials under dry-wet alternation (55％ water filled pore space and flooding) conditions,so as to reveal the effect of iron oxidation on organic carbon sequestration during water transformation.The results showed that the addition of Fe2+ promoted the oxidation of active iron in XR and QR soils,compared with CK (without Fe2+),the average contents of Fe3+ in XR and QR soils increased by 133.87％ and 95.66％,respectively.Under drought condition,compared with CK,the addition of Fe2+ promoted the CO2 emission and accumulation of DOC,the cumulative CO2 fluxes from XR and QR soils increased by 59.77％ and 124.48％,and the average contents of DOC increased by 42.57 ％ and 23.71％,respectively.Under the flooding condition,compared with CK,the addition of Fe2+ inhibited the CO2 emission,the cumulative CO2 fluxes from XR and QR soils decreased by 54.03％ and 35.27％,respectively;the addition of Fe2+ promoted the accumulation of DOC at earlier stage,and inhibited the accumulation of DOC at later stage,the average content of DOC decreased by 35.29％ in XR soil but increased by 16.59％ in QR soil.During the whole period,compared with CK,the addition of Fe2+ significantly decreased cumulative CO2 fluxes in XR and QR soils by 43.87％ and 22.14％,respectively.The results suggested that red soils with rich iron oxide in southern of China had high potential in organic carbon sequestration.
Keywords：dry-wet alternationpaddy soilsiron oxidationdissolved organic carbonCO2 emission
Publication Date：2017-01-01
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：5( 72-76 )