Soil survey and soil classification of the Koupendri catchment in Benin, West Africa

Abstract

Lack of detailed soil data has been a major constraint to hydrological modeling and making of agronomic decisions in the Koupendri Catchment. A soil survey was carried out to characterize and classify the soils of the 11.8 km 2 catchment using Soil and Terrain (SOTER) approach. The soils were classified using the soil taxonomy (USDA) and the world reference base for soil resources (WRB) classification systems. The soil map produced at a scale of 1:25000 using FAO/UNESCO legend showed five distinct soil types. The dominant soil type-Dystric Plinthosols-covered about 55% of the area and supports few crop productions but make plantation agriculture almost impossible. The soils are slightly acidic to alkaline, predominantly silty to clayey in texture with good to imperfect drainage, low permeability and high bulk density that impedes root growth. The poor soil organic carbon content, total nitrogen, available phosphorus, cation exchange capacity, base saturation and other basic exchangeable cations with moderately leached horizons indicated low-moderate fertility status of less weathered soils. The soils belong to three major soil orders: Ultisols, Inceptisols and Alfisols (USDA), and reference soil groups: Plinthosols, Cambisols, Luvisols and Gleysols (WRB). The WRB gave a better and detailed soil classification compared to USDA, and thus should be used in subsequent classification of soils in the region.

Soil Damage Potential Index Based on Weighting Scoring Analysis and Utilization of Geographical Information Systems

“…Nineteen observation points with a percentage of 86.36% soil type in the Inceptisol order with land use as dry fields, forests, plantations, rice fields, shrubs. Inceptisol soil is soil that is starting to develop with marked formation of a soil horizon on the cambic endopedon (Azuka et al, 2015;.…”

Socio-demographic and economic characteristics, crop-livestock production systems and issues for rearing improvement: A review

“…It is highest in the south of the country (about 100-200 per km 2 ) and lowest in the north (about 15-60 per km 2 ). Average 70% of the population is rural (INSAE, 2008;Azuka et al, 2015).…”

“…The chemical composition of these substrates shows an accumulation of ferric oxides and hydrates with low concentrations of aluminium oxide and low exchangeable cations capacity (2-8 cmol + /100g), but with high base saturation (80-95%). Organic matter content is very low (0.5-1.5%) and soils are deficient in N (0.01-0.03%) and assimilable P (1-3 ppm Bray) (Youssouf and Lawani, 2002;Azuka et al, 2015).…”

Biomass allocation in five semi-arid afforestation species is driven mainly by ontogeny rather than resource availability

“…The vegetation is typical for a Sudan savanna ecological zone, with parklands, forest patches, and agricultural and fallow land, all of which are impacted by human activity (Saïdou et al 2004;Chabi et al 2016). The soils are compacted, limited in their depth by gravel and lateritic formations, and have low to moderate inherent fertility (Saïdou et al 2004;Azuka et al 2015). The soil at the research site was classified as an epipetric plinthosol with sandy-loamy texture in the surface layer and loamy soil dominated by clayey loam in deeper layers.…”

“…In sub-Saharan Africa (SSA), these efforts are increasingly constrained by the decline in the per capita availability of agricultural land (de Graaff et al 2011), required to satisfy the food, feed, and fuel demands of the ever-increasing population. The resulting pressure on marginal land (Azuka et al 2015) has dramatically reduced the duration of fallows, the traditional practice used to restore soil fertility (Nandwa 2001). The increasing variability of rainfall in SSA (Sylla et al 2016) has become an additional obstacle for efforts to improve cropland productivity and regenerate forest areas.…”