Effects of Cover Crops and Soil Amendments on Soil CO2 Flux in a Mississippi Corn Cropping System on Upland Soil

Abstract

Agroecosystems, accounting for more than one-third of arable land worldwide, play an essential role in the terrestrial carbon (C) cycle. The development of agricultural practices, which maximize soil C sequestration from the atmosphere, is receiving growing attention due to the recognition of agroecosystems’ great potential to serve as sinks of atmospheric carbon dioxide (CO2). In particular, cover crop and soil amendment applications are generating much interest in mitigating climate change and enhancing agricultural ecosystem services. The objective of this study was to evaluate the effects of winter cover crop and soil amendments, including broiler litter (BL), flue gas desulfurization (FGD) gypsum and lignite, on soil CO2 flux from cropping systems in southeastern USA, where related studies were limited. A field study was conducted from 2019 to 2021 in a Mississippi upland corn cropping system with measurements of soil CO2 flux, moisture and temperature during cash crop growing seasons. We observed high temporal variability in soil CO2 flux with flux peaks between late June and early July, which is likely due to the temporal changes in soil moisture. A significant increase in soil CO2 flux was found with BL application (p < 0.05). Co-application of FGD gypsum and lignite with BL-reduced soil CO2 flux by 15–23% but did not fully eliminate the rising effects. Significantly higher soil CO2 flux and lower soil temperature were observed from fields with cover crops than those without cover crops in the third year of this study (p < 0.05), which is likely attributed to the higher organic C content accumulated in soil with cover crops. Future research should assess year-round soil greenhouse gas fluxes in both cash crop and cover crop growing seasons using a high temporal resolution measurement scheme.

Evaluating Best Management Practice Efficacy Based on Seasonal Variability and Spatial Scales

“…CC residue could also help in improving soil moisture, infiltration, and soil hydraulic conductivity [87][88][89][90][91][92]. The results from this study were consistent with the previous literature [12,14,40,41,45,[66][67][68][69]75,[93][94][95].…”

Spatial variability of agricultural soil carbon dioxide and nitrous oxide fluxes: characterization and recommendations from spatially high-resolution, multi-year dataset

“…Likewise, the field-wide mean CO2 flux was also similar across sites and years, especially for the sites under conservation management under crop rotation between corn and soybean. These field-scale soil CO2 fluxes are comparable to past reports and are within the typical range for the Midwestern corn or soybean systems (Allaire et al, 2012;Ding et al, 2007;Hu et al, 2023). The mean cumulative flux was on average about 32% greater in the conventionally managed Villa Grove site.…”

Improvement in Wheat Productivity with Integrated Management of Beneficial Microbes along with Organic and Inorganic Phosphorus Sources

“…Despite the advantages of organic manuring the crops, some researchers reported that bioavailable organic C, N, and P are abundant in organic manure, which provides abundant C, energy sources and substrates for microbes to flourish. This raises microbial activity, which in turn increases microbial respiration and soil CO 2 flow [49]. However, organic manure that has been deeply incorporated into the soil can lower nutrient runoff and CO 2 emissions [50].…”