Selected physical and chemical properties of soil under different agricultural land-use types in Ile-Ife, Nigeria

This study examined changes in soil properties under different types of agricultural land-use. This was done with a view to extending knowledge on the nature of soil properties under long-term land-use practices. The study investigated six types of land-use: paddock, continuously cropped, secondary forest, teak, oil palm, and cacao plantations. Soil strength and saturated hydraulic conductivity were determined in-situ at two soil depths (0–15 and 15–30 cm) across the land-use types. Soil samples were collected to determine particle size distribution, bulk density, aggregate stability, pH, organic carbon, cation exchange capacity, total nitrogen, and available phosphorus. The data obtained were subjected to analysis of variance and Duncan's multiple range test was used to separate significant means at p ≤ 0.05. The results showed that land-use types such as forest, cacao and continuously cropped had higher saturated hydraulic conductivity, while soil bulk density was highest under continuously cropped land-use type (1.55 g cm(−3)). The soil aggregates of forest, teak, and oil palm land-use types were more stable, but soil under oil palm land-use had the highest soil strength (5.65 kg m(−2)). Soil pH across the land-use types was slightly acidic to strongly acidic, while soil organic carbon was least in continuously cropped land (3.87 g kg(−1)). The total nitrogen content of soil across the land-use types was high, but the available phosphorus was low. Paddock, cacao, and continuously cropped land-use types had higher cation exchange capacity. The results implied that continuous cultivation led to depletion in soil physical and chemical properties, whereas, afforestation and cultivation of tree crops conserved soil properties better. Therefore, the establishment of tree crop plantations and conservative soil management practices such as manuring, mulching, liming, and conservation tillage were suggested to prevent agricultural lands from degradation in areas with soils under similar conditions.