Wollastonite addition can significantly inhibit greenhouse gas emissions of freeze-thaw farmland soil

We investigated the effects of different treatments on soil nutrients and greenhouse gas (GHG) emissions in winter. A field experiment was conducted with four treatments: control (C), wollastonite application (CaSiO3+C), winter warming (WW), and wollastonite application + winter warming (CaSiO3+WW). The results showed the following: (1) Under the background of winter warming, the fluctuation of soil moisture and temperature increased; most of the soil carbon and nitrogen nutrients were lost; the cumulative fluxes of N2O, CH4, and CO2 increased by 58.18 %, 196.21 %, and 63.00 %, respectively, and global warming potential (GWP) increased by 62.26 %. (2) The contents of SOC, MBC, TN, TDN, NH4+-N, and MBC:MBN of farmland soil decreased after wollastonite application in winter; the cumulative fluxes of N2O, CH4, and CO2 decreased by 41.42 %, 71.72 %, and 40.84 %, respectively, and the GWP decreased by 41.30 %. (3) Under the background of winter warming, the application of wollastonite led to significant decreases in the contents of DOC, MBN, and Ca2+ in farmland soil; the cumulative fluxes of N2O, CH4, and CO2 were reduced by 47.76 %, 106.31 %, and 29.23 %, respectively, and the GWP was reduced by 30.95 %. Multiple linear regression showed that soil surface water-thermal, nutrients, and microorganisms together affected N2O emissions (R2 = 0.759). CH4 was mainly affected by soil nutrients and microorganisms (R2 = 0.237), and soil surface water-thermal and nutrients affected the CO2 flux (R2 = 0.771). Soil nutrients were the key factors affecting N2O and CH4 emissions, and the soil surface water-thermal was the key factor affecting CO2 emissions.