Variability of Characteristics and Productive Potential of Some Pedons on the Basement Complex of Southwestern Nigeria

The objective of this study is to assess variability of land quality and soil characteristics of some of the pedons on the basement complex of southwestern Nigeria. Variation in soil properties and their relationship with crop production must be studied and understood to ensure sustainability of soil. Soil characteristics can vary significantly across most fields used for crop production. Interaction among the parent materials, topography, vegetation, tillage, fertilization, make variation across fields the norm rather than the exception. Some soil chemical parameters of pedons on two locations (Alaho-Olokutaand Ajibode) were assessed.
Coefficient of variation was used to evaluate the level of variability of the parameters. The coefficient of variability for pH (Top and Subsoil) for both sites was <15%; for site 1 top soil most of the pH falls below 15%, likewise for site 2 except Balogun series with CV 22.94%. Total N and Organic carbon were extremely variable among the pedons and between the two sites. Organic C in site 1(167, 160, 125, 90.35, 235, 20.9, 134 and 107, 96.41, 40.0, 53, 89, 120, 78%), site 2(102, 105, 133, 71.39, 164, 11.1 and 111, 48.4, 68.26%) respectively.
In site 1, potassium has the least variability while in site 2 it was moderately variable except for Balogun series. ECEC, topsoil and subsoil; (15.78, 14.19, 10.04, 12.55, 19.78, 35.14 and 13.16, 5.15, 5.16, 2.05, 7.94, 3.60, 12.10, 3.69%) was least for site 1, it varied for site 2 topsoil and subsoil ranges from least to moderately variable (25.5, 4.7, 4.6, 7.1, 18.6, 21.9, 15.2, 0.01, 7.5, 4.4, 26.5 and 16.6%) respectively. Results from this investigation showed that the key knowledge of soil chemical and physical properties could influence organic and inorganic fertilizer application at the appropriate time to ensure sustainable crop production on the soils.