Pluvial Flooding Impacts on Soil Properties under Oil Palm (Elaeis guineensis) Plantation in a Lowland Humid Tropical Environment of Southern Nigeria

Abstract

Flooding has been a major threat not only to the socioeconomic growth and development of tropical countries but also on their agricultural farmlands. Therefore, this study assessed the impact of pluvial flooding on the morphological, physical, chemical and biological properties of soils under oil palm (Elaeis guineensis) plantation in a lowland humid tropical environment of southern Nigeria. A total of eighteen (18) soil samples were collected from flooded and non-flooded sites at three respective soil depths (0-15, 15-30 and 30-45 cm). Soil samples were analyzed in-situ for their key morphological features while the selected physical, chemical and biological properties were determined following standard laboratory methods. Results indicated the dominance of sand fractions in all the test soils and they were slightly acidic. Pluvial flooding had increasing effects on iron - Fe (47.20, 51.26 and 54.50 mg kg^-1) and manganese - Mn (2.66, 2.63 and 2.16 mg kg^-1) across the three soil depths. However, the poorly drained soils were deficient in copper (Cu) concentrations and inhibited the proliferation of bacteria and fungi. Organic carbon (OC), total nitrogen (TN) and available phosphorous (Avl P), as well as the exchangeable cations (calcium - Ca, sodium - Na, potassium - K and magnesium - Mg) were rated adequate. The study concluded that the deficiency of Cu element in all the test soils may inhibit oil palm plant and root growth.