Residue incorporation mitigates tillage‐induced loss of soil carbon in laboratory microcosms

Abstract

Annual horticultural systems rely on frequent and intensive tillage to prepare beds, manage weeds and control insects. But this practice reduces soil organic carbon (SOC) through accelerated CO 2 emission. Crop residue incorporation could counteract this loss. We investigated whether vegetable systems could be made more resilient by including a high-residue grain crop such as sweet corn (Zea mays L. var. rugosa), in the rotation through the use of conventional (no residue, no soil sieving) and organic (residue incorporated and soil sieved) soil management scenarios. We evaluated short-term emission of CO 2 -C and soil C content in incubated Chromosol and Vertosol soils (Australian Classification) with and without sieving (simulated tillage) or the incorporation of ground sweet corn residue. Residue treatment emitted 2.3 times more CO 2 -C compared to the no-residue treatment, and furthermore, sieved soil emitted 1.5 times more CO 2 -C than the unsieved across the two soil types. The residue incorporation had a greater effect on CO 2 -C flux than simulated tillage, suggesting that C availability and form can be more important than physical disturbance in cropping soils. The organic scenario (with residue and sieved) emitted more CO 2 -C, but had 13% more SOC compared with the conventional scenario (without residue and unsieved), indicating that organic systems may retain more SOC than a conventional system. The SOC lost by soil disturbance was more than offset by the incorporation of residue in the laboratory conditions. Therefore, the possible SOC loss by tillage for weed control under organic management may be offset by organic residue input.

Long-term conservation tillage influences the soil microbial community and its contribution to soil CO2 emissions in a Mollisol in Northeast China

“…Whereas those increase of soil CO 2 flux under MP by tillage may be offset by the soil microbial respiration under RT as the tillage effect was less pronounced in the residue treatments (Bajgai et al 2014). Soil microbial PLFAs under RT were higher than that under MP at 0-30 cm soil depths (Fig.…”

“…Most importantly, the decomposition of crop residues with NT was lower than that with MP and RT, where residues were incorporated into the soil (Curtin et al 2000). The residue-incorporated treatments led to more CO 2 -C flux (2.3 times) compared to the no-residue treatments, and the tillage effect was less pronounced in the residue treatments (Bajgai et al 2014).…”

“…Because NT did not significantly increase soil PLFAs content at 0-30 cm soil depths (Fig. 4), while the soil disturbance under MP may increase soil CO 2 flux, especially when soil disturbance (MP) with residues incorporated into the soil led to significantly increased CO 2 -C flux compared with the undisturbed treatments (Bajgai et al 2014). This response could be due to the increase in the air transport coefficient from soil loosening related to the degree of soil disturbance (Reicosky et al 1997;Morell et al 2010) and to the increase in aggregate disruption and exposure of protected organic matter to decomposition (La Scala et al 2008), and the increases in C mineralization (or short-term priming effect) caused by an increase in soil aeration induced by tillage (Wuest et al 2003).…”

Legume cover crop type and termination method effects on labile soil carbon and nitrogen and aggregation

“…Li et al, 2018). However, this C and N release is small compared with the enhanced mineralization of buried cover crop residues (Bajgai et al, 2014;Nevins et al, 2021). This mineralization may increase adoption rates for cover cropping because incorporated legume cover crops have been followed by crop yields equivalent to crops fertilized with either organic (Wilson et al, 2019) or mineral fertilizer (Spargo et al, 2016).…”

Influence of tied-ridge with biochar amendment on runoff, sediment losses, and alfalfa yield in northwestern China

“…In addition, mulching retains soil moisture, hence increases rainfall infiltration and decreases evapotranspiration ( Li, Li & Pan, 2020 ). Decomposed mulching materials increase soil organic matter and available soil nutrients for crop development ( Jiménez et al, 2016 ; Bajgai et al, 2014 ; Jordán, Zavala & Gil, 2010 ). There have been significant reports on effectiveness of mulching in reducing soil water and nutrient loss in different climatic environments in America ( Ruy, Findeling & Chadoeuf, 2006 ), Europe ( Fernández et al, 2012 ; Abrantes et al, 2018 ), Asia ( Wang, Xiong & Kuzyakov, 2016 ), and Africa ( Mwango et al, 2016 ).…”