Spatial distribution of bowal and differences in physicochemical characteristics between bowal and woodland soils in Benin, West Africa

Bowal, is degraded land surface characterized by ferricrete exposure due to soil surface erosion. This study aims at assessing the spatial distribution of bowé in Benin and the physicochemical differences between bowé and soil of adjacent woodlands. Bowé surfaces were identified during field investigations and mapped. Soil samples were taken on the bowé surfaces and nearby woodland. Mann–Whitney test was applied to analyze the different physicochemical characteristics of bowé and woodland. The results show that bowé were directly related to ferruginous soils and rainfall regime. Bowé soils are characterized by significantly lower values of electrical conductivity, organic matter, extractable phosphorus, silt and total nitrogen than woodland soils, while potassium exchangeability of bowé soils is higher. Bowé can be expected wherever ferruginous soils and/or ferricretes are observed under unimodal rainfall regimes condition. The disaggregation of bowé ferricretes may improve the soil physicochemical characteristics and sustain the regrowth of forest under more humid conditions.