Changes in Nutrient Contents of Soil across Different Land Uses in a Forest Reserve

Abstract

In order to assess the changes in soil chemical properties' resulting from conversion of forest to other agricultural land uses a study was conducted in Okomu Forest Reserve (Nigeria). Five soil samples collected from top and sub soils of marked points within the undisturbed forest, farmland, cocoa plantation, oil palm plantation and rubber plantation were analyzed for pH, organic carbon, total nitrogen, available phosphorus, exchangeable acidity, sodium, potassium, calcium and magnesium. The results showed variations in all chemical parameters across the land use types with soil depths (top and sub soils). Soil pH ranged from 4.88 (in the cocoa plantation subsoil) to 6.75 (in the forest top soil). Soils (top and sub soils) of the rubber plantation, forest and cocoa plantation had the highest stock of soil organic carbon (SOC), N and exchangeable Na respectively. Available P was highest in the top soil of the rubber plantation and sub soil of the farmland. Exchangeable Ca and Mg were highest in the top soil of the forest and sub soil of the rubber plantation. Exchangeable K and C:N was highest in the farmland top soil and cocoa plantation sub soil. Relationship among the chemical parameters varied with soil depth. Conversion of forest and cocoa plantation resulted in the highest decline (55.78% and 44.40%) in soil N. There is the need to regulate the conversion of natural forests to agricultural lands and plantations as conserve the nutrient cycling processes.

Influence of Land Use Types on Physical and Chemical Properties in Oba Hill Forest Reserve, Iwo, South-western Nigeria

“…Henril et al (2020) reported that the use of forest reserves for other land usage has resulted into sundry and multifarious ecological problems. Soil physical and chemical properties have been used by many researchers for assessing the influence of land-use on changes and management of the ecosystem (Mitchel et al, 2010;Agboola et al, 2017;Akintola et al 2020a andb, Akintola et al 2021). The management of soil and the maintenance of its quality depend widely on frequent evaluating of soil properties to farming, cultivation and other land use (Chima et al, 2009)) Thus, it is paramount to understand the effects of land use types on soil properties for environmental sustainability and management.…”