Pedogenic Assessment of Hydromorphic Soils in Two Inland Valley Swamps in Ogbomoso and Ondo, Southwestern Nigeria

Abstract

This study investigated the physical, chemical and morphological properties of hydromorphic soils in two inland valley swamps and evaluated their suitability for crop production in Ogbomoso and Ondo, Southwestern Nigeria. The study was conducted at two Teaching and Research Farms of two Universities: Ladoke Akintola University of Technology, Ogbomoso and Wesley University, Ondo. Two pits were dug at each site and soil samples were collected from each profile pit at all the identified genetic horizons. Prepared composite soil samples were subjected to laboratory analysis for the determination of selected physical and chemical characteristics following standard procedures. Data generated were subjected to descriptive statistics, including range, mean, standard deviation and coefficient of variation. The study showed that Ogbomoso soils were deep (> 100 cm depth) and the soil colour ranged from brownish grey (5 YR 5/1) to light greyish (5 Y 6/2) at the top soil. The texture of the top soil varied from loamy sand to sandy loam. The silt/clay ratios ranged from 0.5 to 4.0 with mean value of 1.30. The soil pH was generally acidic with mean values of 5.32. Three of the basic cations (potassium, sodium, calcium) were generally low with mean values of 0.18, 0.10 and 0.77 cmolkg-1 respectively while magnesium was high (1.43 cmolkg-1). Mean values of organic matter (0.92 %), total nitrogen (0.09 gkg-1) and phosphorus (1.60 mgkg-1) contents were low. Extractable iron (0.76 mgkg-1), zinc (2.64 mgkg-1) and copper (3.48mgkg-1) values were very low while manganese (47.71 mgkg-1) was high. Ondo soils characteristics showed similar trend with Ogbomoso soils. The soils were deep (> 120 cm depth), with light grey (5Y 8/2) colour at the top soil. The textures were predominantly loamy sand, the silt / clay ranged from 0.5 to 1.7 with mean values of 1.06 indicating weakly developed soils with young parent materials. The soil pH was generally acidic with mean values of 4.26. Potassium, Sodium, Calcium were generally low with mean values of 0.19, 0.06 and 0.73 cmolkg-1 respectively while magnesium was high (1.67cmolkg- 1). Organic matter (0.77 %), total nitrogen (0.31 gkg-1) and phosphorus (1.61 mgkg-1) contents were low. Iron (1.90 mgkg-1), zinc (2.26mgkg-1) and copper (2.01mgkg-1) were very low while manganese (19.43 mg kg-1) was high. It was concluded that the soils at the two locations were not fully developed and young (Entisols). The low macro and micronutrients in the soils at the two sites indicated need for incorporation of organic and inorganic fertilizers into the soils for optimum crop production.