The regulatory role of endogenous iron on greenhouse gas emissions under intensive nitrogen fertilization in subtropical soils of China

Abstract

Anaerobic batch experiments were conducted to study the regulatory role of endogenous iron in greenhouse gas emissions under intensive nitrogen fertilization in subtropical soils of China. Fe, Fe, and NO-N dynamics and NO, CH, and CO emissions, as well as the relationships between N fertilizer, endogenous iron, and greenhouse gas emissions were investigated. The emissions of NO increased to different extents from all the test soils by N1 (260 mg N kg) application compared with N0. After 24 days of anaerobic incubation, the cumulative emissions of NO from red soils in De'an (DR) were significantly higher than that from paddy soils in De'an (DP) and Qujialing (QP) under N1. However, N application enhanced CH and CO emissions from the red soils slightly but inhibited the emissions from paddy soils. The maximal CH and CO emission fluxes occurred in DP soil without N input. Pearson's correlation analysis showed that there were significant correlations (P< 0.01) between Fe and Fe, NO-N, (NO + N)-N concentrations in DP soil, implying that Fe oxidation was coupled with nitrate reduction accompanied by (NO + N)-N emissions and the endogenous iron played a regulatory role in greenhouse gas emissions mainly through the involvement in denitrification. The proportion of the electrons donated by Fe used for NO production in denitrification in DP soil was approximately 37.53%. Moreover, positive correlations between Fe and CH, CO were found in both DR and QP soils, suggesting that endogenous iron might regulate the anaerobic decomposition of organic carbon to CH and CO in the two soils. Soil pH was also an important factor controlling greenhouse gas emissions by affecting endogenous iron availability and C and N transformation processes.

Fe3O4 nanoparticles affect paddy soil microbial-driven carbon and nitrogen processes: roles of surface coating and soil types

“…Impacts of nFe 3 O 4 @DMSA and nFe 3 O 4 on gas production Iron oxides are regarded as important electron acceptors in subtropical soils, and organic C in soils might be anaerobically decomposed to CH 4 and CO 2 following the reduction of iron oxides. 29 Many studies have explored the effect of nFe 3 O 4 on CH 4 production, with the results aligning with the trend that nFe 3 O 4 stimulate the methanogenesis under the circumstances of anaerobic digestion, 30 wastewater plants, 31,32 and soil ecosystems. 4,11,33 However, this was not the case observed in this study showing the negligible changes in CH 4 production led by nFe 3 O 4 across all soils.…”

Reviews and syntheses: Iron: A driver of nitrogen bioavailability in soils?

“…For example, Fe (III) minerals and Fe complexed with SOM explained nitrous oxide (N2O) emissions across a set of agricultural soils; more than any other intrinsic soil property (Zhu et al, 2013). Similarly, Han et al (2018) found that soil Fe regulates N2O emissions.…”

“…These reactions, which can occur through both chemical or microbial pathways, include chemo-denitrification (Burger and Venterea, 2011) and anaerobic ammonia oxidation coupled with Fe(III) reduction-Feammox (Wan et al, 2021). In addition, Fe is shown to affect rates of denitrification (Wang et al, 2016) and nitrification (Huang et al, 2016a) in experiments with both Fe addition and soil endogenous Fe (Han et al, 2018).…”

Reviews and syntheses: Iron – a driver of nitrogen bioavailability in soils?

“…Increasing evidence shows that Fe specifically represents a major control over N biological transformations, including mineralization (Wade et al, 2018), nitrification (X. Han et al, 2018), and denitrification (Wang et al, 2016;Zhu et al, 2014), as well as their abiotic analogous reactions, such as chemo-denitrification (Burger and Venterea, 2011) and Fe-mediated hydroxylamine (NH 2 OH) oxidation to nitrous oxide (N 2 O) (Bremner et al, 1980). These reac-I.…”