Abstract
Understanding the impacts of agricultural practices on carbon stocks and CO2 emission is imperative in order to recommend low emission strategies. The objective of this study was to investigate the effects of tillage, crop rotation, and residue management on soil CO2 fluxes, carbon stock, soil temperature, and moisture in the semi-arid conditions in the Eastern Cape of South Africa. The field trial was laid out as a split-split-plot design replicated three times. The main plots were tillage viz conventional tillage (CT) and no-till (NT). The sub-plots were allocated to crop rotations viz maize–fallow–maize (MFM), maize–oat–maize (MOM), and maize–vetch–maize (MVM). Crop residue management was in the sub-sub plots, viz retention (R+), removal (R−), and biochar (B). There were no significant interactions (p > 0.05) with respect to the cumulative CO2 fluxes, soil moisture, and soil temperature. Crop residue retention significantly increased the soil moisture content relative to residue removal, but was not different to biochar application. Soil tilling increased the CO2 fluxes by approximately 26.3% relative to the NT. The carbon dioxide fluxes were significantly lower in R− (2.04 µmoL m−2 s−1) relative to the R+ (2.32 µmoL m−2 s−1) and B treatments (2.36 µmoL m−2 s−1). The carbon dioxide fluxes were higher in the summer (October–February) months compared to the winter period (May–July), irrespective of treatment factors. No tillage had a significantly higher carbon stock at the 0-5 cm depth relative to CT. Amending the soils with biochar resulted in significantly lower total carbon stock relative to both R+ and R−. The results of the study show that NT can potentially reduce CO2 fluxes. In the short term, amending soils with biochar did not reduce the CO2 fluxes compared to R+, however the soil moisture increases were comparable.
Highlights
Twenty percent of the global atmospheric CO2 concentration is emitted from agricultural lands on approximately 37% of the earth land surface [1]
The results of this study show that switching from conventional tillage (CT) to Conservation agriculture (CA) in the Eastern Cape Province changes the vertical distribution of soil organic carbon (SOC) in the soil profile, resulting in a decrease in the SOC with depth
This study provided insights into the impact of CA on CO2 fluxes from semiarid climatic conditions in South Africa
Summary
Twenty percent of the global atmospheric CO2 concentration is emitted from agricultural lands on approximately 37% of the earth land surface [1]. Conventional farming practices such as residue removal and/or burning, continuous tillage with heavy use of machinery, and too much fertilizer usage are responsible for the loss of half of the soil organic carbon (SOC) and contribute about 25% of the total anthropogenic CO2 emissions [4,5]. The continued increase in the atmospheric CO2 concentration is responsible for unpredictable and extreme rainfall events and temperatures [6] and, subsequently, crop and soil productivity loss and food insecurity. Implementing CA practices can potentially increase biomass production [9]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
