Variation of soil properties under different landscape positions and land use in Hunkuyi, Northern Guinea savanna of Nigeria

The food insecurity problem in developing countries has been linked to rapid rates of soil loss and decline in fertility in tropical environments which are characterized by insidious topography. This study was conducted to assess the relationship between topographic positions, land use, and soil characteristics. Three slope classes were considered with six pedons; two on each slope position were opened, described, sampled, and analysed for morphological and physicochemical properties. The results showed that the soils were deep to very deep with drainage improving from HK1 soils (very poorly drained) to HK3 (well-drained). The mean sand fraction ranged between 320 and 740 g kg−1, while bulk density had values between 1.20 and 1.80 M gm−3. The cation exchange capacity (CEC) of the soils with values from 5.6 to 10.4 cmol (+) kg−1 was generally lower on the surface than the subsurface soils. The different landscape positions alongside variation in land use substantially influence variations in soil properties of the study area. The influence of topography was noticed for sand values and soil reaction (pH) along the slope, as mean pH values were significantly (P ≤ 0.05) higher for HK1 compared with HK2 and HK3. Intensive cultivation of soils due to rainfed and irrigated land use on middle slope position (HK2) alongside its strong slope gradient resulted in significant variation in total exchangeable bases (TEB) ((P ≤ 0.05), base saturation (P ≤ 0.05), available P ((P ≤ 0.01), and exchangeable Ca and Mg (P ≤ 0.05).