Ferrate-Modified Biochar for Greenhouse Gas Mitigation: First-Principles Calculation and Paddy Field Trails

Abstract

Modified biochars have attracted attention for reducing greenhouse gas emissions in paddy fields. However, material screening difficulties and lengthy effect validation periods have restricted their development. We proposed a theoretical calculation method to guide short-term field trials in this study. Utilizing first-principles calculations, we determined that sodium ferrate-modified biochar (Fe@C) would limit methane (CH4) and nitrous oxide (N2O) emissions. Field trials confirmed that Fe@C increased rice yields and active organic carbon content in soil and reduced methane emissions and the global warming potential. However, applying sodium ferrate alone significantly reduced N2O emissions. Correlation analysis showed that methane was significantly negatively correlated with yield and the soil carbon pool labile index. N2O was significantly negatively correlated with urease activity, and significantly positively correlated with the soil carbon pool management index. Therefore, Fe@C provides a high-yielding management measure that enhances soil labile organic carbon. Additionally, its effects were controlled by the proportion of sodium ferrate. Our work provides a new strategy to guide the design of paddy field experiments via theoretical calculations, greatly shortening research time and providing solutions for carbon sequestration and emissions reduction.

Biochar-Soil-Plant interactions: A cross talk for sustainable agriculture under changing climate

“…Naturally, atmospheric CO 2 can be directly absorbed through plants by photosynthesis process. Part of the absorbed CO 2 is released back into the atmosphere through respiration, and the rest is sequestered first as plant biomass and then as soil organic carbon during the decomposition process of the plant biomass (Zhou et al, 2022). Further decomposition of soil organic carbon discharges the C as CO 2 into the atmosphere within a short duration.…”

A theoretical study of the effect and mechanism of FeN3-doped biochar for greenhouse gas mitigation

“…The localized d electrons of the Fe element have been described via the DFT + U method, with the U value set to 4 eV (Zhou and Sun 2011;Wang et al 2022a). The cutoff energy, convergence standard of energy, and force were set to 500 eV, 10 − 5 eV, and 0.02 eV Å −1 , respectively (Zhou et al 2022). The k mesh of the structure optimization and density of state (DOS) calculations were set to 3 × 3 × 1 and 11 × 11 × 1 with the Gamma-centered grids (Froyen 1989;Liu et al 2021).…”

“…The global average temperature from 2020 to 2021 has increased by 1.1℃ compared with 1850-1900 and will continue to rise in the future (IPCC, 2021). The major inducement of global warming is the sharp enhancement of atmospheric concentrations of greenhouse gases (GHGs) [for instance, methane (CH 4 ), nitrous oxide (N 2 O), and carbon dioxide (CO 2 )] (Wang et al 2019;Zhou et al 2022). According to statistics in 2015, the accumulation concentrations of CH 4 , N 2 O, and CO 2 in the air increased by 150%, 20%, and 40%, respectively (Stocker et al 2014;Tian et al 2015).…”