Dry-season autotrophic and heterotrophic soil respiration in contrasting agroecological settings

ABSTRACT

In arid Africa, it is unclear how the transition from grassland to cropland affects CO₂ fluxes and whether these effects are climate-dependent. From November 2019 to March 2020 (dry season), we studied autotrophic (Ra) and heterotrophic (Rh) soil respiration. At highlands, grazing land (1.18 ± 0.13 µmol m⁻² s⁻¹) and teff croplands (1.36 ± 0.14 µmol m⁻² s⁻¹) had the lowest Rh, while acacia decurrens plantations (1.94 ± 0.19 µmol m⁻² s⁻¹) were the largest. When compared to teff (2.08 ± 0.20 µmol m⁻² s⁻¹) and khat (1.73 ± 0.24 µmol m⁻² s⁻¹), grazing land in the midland had a lower Rh (1.18 ± 0.13 µmol m⁻² s⁻¹). Ra on teff (1.51 ± 0.27 µmol m⁻² s⁻¹) was substantially (P < 0.05) greater than on grazing land (1.08 ± 0.32 µmol m⁻² s⁻¹) in the highlands. Grazing lands (1.54 ± 0.21 µmol m⁻² s⁻¹) have a considerably (P < 0.05) greater Ra than farmlands (teff, 0.20 ± 0.07 µmol m⁻² s⁻¹; groundnut, 0.09 ± 0.03 µmol m⁻² s⁻¹) in lowlands. Growing teff in the highlands and midlands will result in higher CO2 fluxes into the atmosphere. However, in-depth research is needed to implement effective land management that reduces CO₂ emissions.

KEYWORDS:

• Drought-prone
• land use
• soil moisture
• soil respiration partition
• soil temperature

Acknowledgements

We acknowledged the Japan Science and Technology/Japan International Cooperation Agency for funding this research through the Japan Science and Technology Research Partnership for Sustainable Development (SATREPS, grant number JPMJSA1601). We would also like to express our gratitude to the SATREPS project team at Bahir Dar University, Ethiopia, for their excellent collaboration in the laboratory and fieldwork.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data analyzed during the current study are available from the corresponding author on rational request.

Additional information

Funding

This study was funded by the Science and Technology Research Partnership for Sustainable Development (SATREPS, grant number JPMJSA1601), and the Japan Science and Technology Agency (JST) / Japan International Cooperation Agency (JICA).

Notes on contributors

Genetu Fekadu

Genetu Fekadu (M.Sc.) is a PhD candidate at Bahir Dar University in the soil science program and a lecturer at the University of Gondar, Ethiopia.

Enyew Adgo

Enyew Adgo (PhD) is a Professor and researcher at Bahir Dar University, Ethiopia.

Derege Tsegaye Meshesha

Derege Tsegaye Meshesha (PhD) is an Associate Professor and researcher at Bahir Dar University, Ethiopia.

Atsushi Tsunekawa

Atsushi Tsunekawa (PhD) is a Professor and researcher at Tottori University, Japan.

Nigussie Haregeweyn

Nigussie Haregeweyn (PhD) is a Professor and a researcher at Tottori University, Japan.

Fei Peng

Fei Peng (PhD) is an Associate Professor and a researcher at the Chinese Academy of Sciences, China.

Mitsuru Tsubo

Mitsuru Tsubo (Professor) is a Professor and researcher at Tottori University, Japan.

Asaminew Tassew

Asaminew Tassew (PhD) is an Associate Professor and researcher at Bahir Dar University, Ethiopia.

Gizachew Ayalew Tiruneh

Gizachew Ayalew Tiruneh (PhD) is an Assistant Professor and lecturer at Debre Tabor University, Ethiopia.

Nigus Tadesse

Nigus Tadesse (M.Sc.) is a PhD student at Bahir Dar University, College of Agriculture and Environmental Sciences, Ethiopia.

Tsugiyuki Masunaga

Tsugiyuki Masunaga (Professor) is a Professor and researcher at Shimanie University, Japan.