Vertisols and Cambisols had contrasting short term greenhouse gas responses to crop residue management

Abstract

In sustainable agriculture crop residues management should consider the interactions between soil and residue properties, which can affect the decomposition and global greenhouse gases (GHGs) emission. Through a laboratory experiment, we investigated the effect of the management (incorporation and surface placement) of wheat and faba bean residues on their decomposition and CO<sub>2</sub>, CH<sub>4</sub> and N<sub>2</sub>O emissions from two soils, a Chromic Vertisol and an Eutric Cambisol. In the Vertisol, wheat residues increased the CO<sub>2</sub> emission more than faba bean when left on the surface whereas no differences among residues were observed when incorporated. In the Cambisol, faba bean emitted more than wheat when left in the surface and less when incorporated. Total CH<sub>4</sub> emissions were higher in faba bean in Cambisol for both management and only when applied in the surface in Vertisol. Total N<sub>2</sub>O emission in the Vertisol was higher when faba bean was incorporated, and wheat was left on the surface. In the Cambisol, wheat addition increased total N<sub>2</sub>O emissions by 20% compared to faba bean, with no differences between managements. Our study confirmed that contrasting properties among tested soils resulted in significant interactions with residues own degradability and their placement affecting residue decomposition, soil C and N dynamics, and GHGs emission.

Agricultural soils: A sink or source of methane across the British Isles?

“…In , adjacent intensively managed grazed grasslands were tilled in spring, resulting in a large increase in CH 4 emissions (Figures 4 and 5). This was likely to be a result of the incorporation and subsequent decomposition of grass into the lower soil layers, providing the necessary anaerobic conditions and carbon source for methanogenesis (Badagliacca et al, 2020). Taking simplistic means of the fluxes before tillage and the mean of fluxes after tillage (up to 150 days), fluxes increased from −0.03 ± 0.07 nmol m −2 s −1 to 4.03 ± 1.29 nmol m −2 s −1 .…”

Repeated Solid Digestate Amendment Increases Denitrifying Enzyme Activity in an Acid Clayey Soil

“…Then, it is necessary to take into account the fact that the triggered microbial biomass and respiration conditions, resulting from the solid digestate application, can determine a reduction in the O 2 concentration in the soil and, thus, further stimulate the selection of denitrifying microorganisms [68,71,72]. This circumstance in the studied soil could be exacerbated by its clayey texture, which leads to a lower gas diffusivity and a higher incidence of anoxic microsites [73,74].…”