Soil Quality Dynamics under Isolated Stands of Irvingia gaboneensis (Bush Mango) and Within the Rainforest in Isoko Region, Nigeria

Abstract

This study investigated soil quality dynamics under isolated stands of Irvingia gaboneensis within the rainforest of Isoko South region in Nigeria. Both experimental and quasi experimental designs were adopted; while the study area was stratified into 10 from which 2 sampling sites (I. gaboneensis and rainforest respectively) were selected, making 20 sampling sites examined. Samples of soil were derived from topsoil (0-15 cm) and subsoil (15-30 cm) layers of soil under I. gaboneesis and rainforest using core sampler. Each selected site of 30 m x 30 m was divided into quadrant of 10 m x 10 m from which samples were taken. Laboratory analyses of the samples were carried out following standard procedures. All data generated were statistically analysed using descriptive and paired t-test. Results revealed that soil attributes varied under I. gaboneensis and rainforest. With t-value = 0.114 and P (0.9110) > 0.05, mean differences in the topsoil are not significant. For the subsoil, t-value = 0.706 with P (0.4980) > 0.05 thus, mean differences in the subsoils are not significant. Also, with t-value = 1.0250 and P (0.3320) > 0.05, mean differences between the topsoil and subsoil under I. gaboneensis is not significant. For the rainforest, the t-value = 1.1520 and P (0.2790) > 0.05, mean differences between the topsoil and subsoil under adjoining rainforest trees is not significant. The observed insignificant difference in properties of soils under I. gaboneensis and rainforest shows the capacity of I. gaboneensis in soil management. Therefore, its conservation should be encouraged to manage the degraded rainforest ecosystem, while their incorporation into agro-forestry farming should be encouraged