Resource information
Southwestern Nigeria is replete with soils that have high gravel contents within the subsoils. Most of these soils are being opened up for cultivation as other land uses (roads and housing) are competing for agricultural lands. It is imperative that these soils be properly studied and managed to prevent serious land degradation, which may over the long term militate against food production in most rural communities. Thus, the objectives of these investigations were to assess the soil profile gravel contents, texture, cation exchange capacity (CEC), soil organic matter (SOM), and SOM/silt + clay (or SSC ratio) of these soils; assess which of these pedons will be susceptible to degradation using the SSC ratio; and evaluate the relationship that exists, if any, among the aforementioned variables. A semidetailed survey was conducted on 810 ha of land (7° 40′ N and 7° 45′N; 4° 25′ E and 4° 30′ E) located in the rain forest (RF) agroecological zone (AEZ) of southwestern Nigeria. Eighteen soil types/pedons were identified. Subsequently, profile pits (1.50 m) were dug, and soil samples were collected, bagged, labeled, and air dried. These samples were used to determine the proportion of gravel (>2 mm) in the soil, and the
