Soil factors influencing the availability of manganese under different land-use systems in coastal plain sands derived soils of Umudike, Nigeria

Abstract

The research was conducted in March, 2017 at the Michael Okpara University Agriculture, Umudike, Nigeria to investigate soil factors influencing the availability of Mn in soils under different land-use systems. Soil samples were collected from two depths (0-20 and 20-40 cm) from five selected land use types, cassava farm, natural fallow, rice farm, forest and grazing fields. Available Mn in the soils was determined using four extractants; Coca-Cola, EDTA, HCl and NH₄OAc. The results showed that, higher mean values of physico-chemical properties were generally recorded in the surface (0-20 cm) compared to the subsurface (20-40 cm) soil layer and were also significantly affected by the land use. The highest and the lowest mean values of available Mn were obtained in flood rice farm and cassava farm, respectively. The availability of Mn varied widely depending on the used extraction which were in the order of Coca-Cola > EDTA > NH₄OAc > HCl extractants. Manganese extracted by all extractants was well correlated with organic matter, pH and ECEC, which suggests that these soil properties were responsible for the availability of Mn in the soils under different land use systems.