Assessing the effect of crop residue removal on soil organic carbon storage and microbial activity in a no‐till cropping system

Abstract

Changes in agricultural management strategies have received much attention in recent years with a view to increasing or maintaining the amount of carbon (C) sequestered as soil organic C (SOC). In many parts of the world, minimum or no‐till management has been promoted as a means of improving soil quality, reducing losses of erosion and potentially increasing SOC stocks. However, no‐till systems can become problematic and potentially disease‐prone, especially due to high crop residue loadings. Consequently, residue removal either by harvesting or burning off may be employed to reduce these pressures. Here, we examined the effect of crop residue removal on C storage in soil that had been under no‐till management for 20 yr. We predicted improved physical properties (i.e. lower bulk density) and greater microbial activity under the residue retention soils due to greater readily available C and nutrients derived from crop residues. In contrast, we predicted relative reductions in SOC in the no residue soils due to a lack of available residue‐derived C for microbial use. Residue removal caused a relative C loss from the soil, which was related to C input, amount of nutrient availability and microbial activity. We demonstrate the importance of maintaining crop residue cover in no‐till cropping systems for soil function and highlight the potentially deleterious effects of changing management strategy to increased residue harvesting or removal by burning.

Assessing the Climate Regulation Potential of Agricultural Soils Using a Decision Support Tool Adapted to Stakeholders' Needs and Possibilities

“…When reduced tillage or no-till is combined with increased C inputs, e.g., the incorporation of crop residues, the model does predict a higher C sequestration. This is in line with field observations, which have shown that reduced tillage or no-till only lead to increased SOC stocks when combined with increased C inputs (Luo et al, 2010;Virto et al, 2012;Chowdhury et al, 2015).…”

Effect of tillage and crop management on runoff, soil erosion and organic carbon loss

“…Similar results were reported by Sombrero and Benito (2010) after 3 years of research, in which they observed that the SOC content was 11 ± 0.4% greater for NT than for CT. The increase in organic carbon content may have been caused by the accumulation of crop and biomass residues, especially where NT was used, as NT is able to compensate for organic matter in the topsoil (Chowdhury, Farrell, Butler, & Bolan, 2015; Reicosky & Allmaras, 2003).…”

Sustainable soil use and management: An interdisciplinary and systematic approach

“…A variety of conservation farming practices can increase SOC levels, while also increasing crop productivity and decreasing water demand (Kumar et al, 2019;Mehra et al, 2018). Crop residue return to surface soils can have a positive effect on soil carbon sequestration (Chowdhury et al, 2015;Li et al, 2019b). For example, chopping and returning wheat straw and corn stover can increase SOC levels by 14.5% in a double-cropping system (Zhao et al, 2019).…”