Measurement of width, depth and soil loss for gully erosion impact in the Sudan Savannah region, Kebbi State Nigeria

Soil erosion has become global news as it affects soil, environmental and food security in many nations. Gully erosion is one of the serious types of soil erosion that damages soil productivity and soil quality in African drylands. The aim of this study was to measure the impact of gully erosion based on width, depth and soil volume loss in the Sudan Savannah’s dryland of Kebbi State Nigeria. Gully erosion impact was recorded and calculated based on USDA standard method of measuring soil erosion in the field. Results show that the highest soil volume loss (796647.2 m3 ) was recorded at Gwandu whereas the lowest (241.60 m3 ) was recorded at Augie. The maximum width (49.56 m) was recorded at Tarasa and minimum (1.01 m) at Argungu2. Likewise, maximum depth (8.666 m) was recorded at Badariyya and minimum (0.94 m) was recorded at Argungu. The soil physical properties revealed that soil structural configuration were classified as granular, massive and single-grains, and are non-coherent but loose and poorly sorted. Most of the sites have more that 65% sand characterized as low organic matter, nitrogen and CEC. Sites were considerably affected by gully erosion and the impact was physical and quantitative. Soil quality (Sq) and land suitability (Ls) potentials for agricultural production were affected. The affected sites were evaluated as bad land (Sq5, Ls5), notably damaged (Sq4, Ls4) and partially damaged (Sq3, Ls3). The study recommended the use of advanced soil conservation measures across the affected sites, which will employ the adaptation of water harvesting systems, orchard plantation and drainages.