Ferrous Iron Addition Decreases Methane Emissions Induced by Rice Straw in Flooded Paddy Soils

作者：Jin‐Li Hu, Hongtao Wu, Zheng Sun, Qian Peng, Jinsong Zhao, Ronggui Hu · 发表于：ACS Earth and Space Chemistry · 年份：2020 · DOI：10.1021/acsearthspacechem.0c00024 · 被引用次数：33 · 研究领域：Atmospheric and Environmental Gas Dynamics、Soil Carbon and Nitrogen Dynamics、Hydrocarbon exploration and reservoir analysis

Straw returning to fields is a common agricultural practice for enhancing soil fertility and organic matter, although it induces substantial CH 4 emissions from flooded paddy soils. The characteristics of long-term periodic management of irrigation and drainage intensely affect the redox cycling of iron in paddy soil and could be one of the major factors regulating CH 4 production. Currently, this regulatory effect is rarely applied to CH 4 mitigation during straw returning to fields. To clarify the influences of iron on CH 4 emissions induced by straw incorporation, an laboratory incubation experiment was conducted with the addition of rice straw and two different concentration levels of ferrous iron (3.7 and 7.4 g of Fe 2+ kg –1 of soil) to two paddy soils (collected from Luotian, Hubei Province, and Changsha, Hunan Province, China, hereafter called LT and CS soils, respectively). Our result showed that CH 4 emissions from straw addition treatment were 125.4 and 45.5 times greater than the amount without straw addition in LT and CS soils, respectively. Fe 2+ addition significantly decreased CH 4 emissions induced by rice straw by over 50% in both soil samples. Moreover, the stimulation of straw on CH 4 emission was almost offset by twice the content of Fe 2+ amendment in LT soil. Fe 2+ addition significantly decreased the dissolved organic carbon (DOC) content, with 21–39% in LT soil and 31–42% in CS soil, compared to the straw addition treatment. The Fe(II) accumulation ra...