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Interrelationships between terrace development, topography, soil erosion, and soil dislocation by tillage in Minchet Catchment, Ethiopian Highlands
Author(s) -
Subhatu Alemtsehay,
Speranza Chinwe Ifejika,
Zeleke Gete,
Roth Vincent,
Lemann Tatenda,
Herweg Karl,
Hurni Hans
Publication year - 2018
Publication title -
land degradation and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 81
eISSN - 1099-145X
pISSN - 1085-3278
DOI - 10.1002/ldr.3109
Subject(s) - terrace (agriculture) , erosion , tillage , soil conservation , environmental science , hydrology (agriculture) , deposition (geology) , geology , soil science , geography , agriculture , sediment , geomorphology , agronomy , geotechnical engineering , archaeology , biology
This study assesses the interrelationships between terrace development and topographic factors, soil erosion, and soil dislocation by tillage in Minchet Catchment in the Ethiopian Highlands. Data were collected through a mix of modelling soil erosion using the Universal Soil Loss Equation adapted to Ethiopia, and measuring slope and soil deposition above the terraces. The terraces, which developed over 29 years following construction of fanya juu bunds on cropland, reduced the cropland's current slope gradient to half of its original slope, leading to about 39% less soil erosion. Currently, of the total 50 t · ha −1 · yr −1 soil deposition measured above the terraces, about 22 t · ha −1 · yr −1 was soil eroded by water, and the other 28 t · ha −1 · yr −1 was soil that had been dislocated by tillage. This shows that Soil and Water Conservation technologies in the study area are effective in reducing slope gradient and slope length, and thus also in trapping eroded soil, slowing soil movement by tillage, and ultimately, in reducing soil erosion. However, current soil loss from the fields still exceeds the soil formation rate of the study area. We thus highlight possible options to further reduce soil erosion in the crop fields, such as increasing the number of terraces in areas with wider spacing and growing multipurpose and productive grasses and trees on terraces.