Global analysis of cover management and support practice factors that control soil erosion and conservation

Authors: EBABU, KINDIYE - Tottori University; TSUNEKAWA, ATSUSHI - Tottori University; HAREGEWEYN, NIGUSSIE - Tottori University; TSUBO, MITSURU - Tottori University; ADGO, ENYEW - Bahir Dar University; FENTA, AYELE - Tottori University; MESHESHA, DEREGE - Bahir Dar University; BERIHUN, MULATU - Bahir Dar University; SULTAN, DAGNENET - Tottori University; VANMAERCKE, MATTHIAS - University Of Liege; PANAGOS, PANOS - European Commission-Joint Research Centre (JRC); BORRELLI, PASQUALE - University Of Basel; Langendoen, Eddy; POESEN, JEAN - Catholic University Of Leuven

Submitted to: International Soil and Water Conservation Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2021
Publication Date: 6/1/2022
Citation: Ebabu, K., Tsunekawa, A., Haregeweyn, N., Tsubo, M., Adgo, E., Fenta, A.A., Meshesha, D.T., Berihun, M.L., Sultan, D., Vanmaercke, M., Panagos, P., Borrelli, P., Langendoen, E.J., Poesen, J. 2022. Global analysis of cover management and support practice factors that control soil erosion and conservation. International Soil and Water Conservation Research. 10(2):161-176. https://doi.org/10.1016/j.iswcr.2021.12.002.
DOI: https://doi.org/10.1016/j.iswcr.2021.12.002

Interpretive Summary: The effects of land management and conservation practices for the conservation planning tool Revised Universal Soil Loss Equation (RUSLE) are represented by the factors C and P, respectively. Very limited field-scale studies have been conducted to quantify C and P values across a broad range of climate, soils, crops, management and conservation practices. Further, values used by individual case studies are scattered across the literature. ARS researchers from Oxford, MS, in collaboration with researchers from Belgium, Ethiopia, Italy, Japan, and Switzerland, reviewed values of the C and P factors published in 255 peer-reviewed journal papers. The published values varied widely across climatic zones, land use or cover types, and support practices. The C-factor was highest in areas with low rainfall and in cropland, whereas the P-factor was largest at high elevation and in areas with a humid climate and high rainfall. The compiled datasets of C- and P-factor values can be used by researchers and policymakers to support large-scale planning and evaluation of integrated catchment management interventions, particularly as inputs for soil erosion models in areas where it is difficult to obtain empirical information about the impact of land or cover type changes and support practices.

Technical Abstract: Cover management and support practices largely control the magnitude and variability of soil erosion. Although soil erosion models account for their importance (particularly by C and P-factors in the Revised Universal Soil Loss Equation), obtaining spatially explicit quantitative field data on these factors remains challenging. Hence, also our insight into the effects of soil conservation measures at larger spatial scales remains limited. We analyzed the variation in C- and P-factors caused by human activities and climatic variables by reviewing 255 published articles reporting measured or calculated C- and P-factor values. We found a wide variation in both factor values across climatic zones, land use or cover types, and support practices. The average C-factor values decreased from arid (0.26) to humid (0.15) climates, whereas the average P-factor values increased (from 0.33 to 0.47, respectively). Thus, support practices reduce soil loss more effectively in drylands. The global average C factor varies by one order of magnitude from cropland (0.34) to forest (0.03). Among the major crops, the average C-factor was highest for maize (0.42) followed by potato (0.40), among the major orchard crops, it was highest for olive (0.31), followed by vineyards (0.26). The P-factor ranged from 0.62 for contouring in cropland plots to 0.19 for trenches in uncultivated land. The C-factor results indicate that cultivated lands requiring intensive site preparation and weeding are most vulnerable to soil loss by sheet and rill erosion. The low P factor for trenches, reduced tillage cultivation, and terraces suggests that significantly decreased soil loss is possible by implementing more efficient management practices. These results improve our understanding of the variation in C- and P-factors and support large-scale integrated catchment management interventions by applying soil erosion models where it is difficult to empirically determine the impact of particular land use or cover types and support practices: the datasets compiled in this study can support further modeling and land management attempts in different countries and geographic regions.