Herbage Dynamics and Soils of two Different Sites of Calotropis procera (ait) r. Br. (Asclepiadaecae) in the Northern Guinea Savanna Zone of Nigeria

Abstract

The relative abundance of Calotropis procera (Ait) R. Br. (Asclepiadaeceae), types and relative abundance of herb species in association with it and the soil types in two different sites, Tudun Sarki (ABU) and Basawa in the Northern Guinea Savanna zone of Nigeria were assessed. To determine herbage dynamics, herbs in each quadrat of the experimental sites were harvested, sorted out according to species, counted and identified in the herbarium. Simpson’s index, D = ∑P_i² was used to obtain relative frequencies and abundance of species. Soil samples were derived from the quadrats and analysed in the laboratory for physico-chemical and chemical properties. The percentage distribution of herbs in relation to Calotropis procera ranged between 0.09 – 50% and 0.21 – 47.6% for Tudun Sarki(ABU) and Basawa respectively, while percentage distribution of Calotropis procera ranged between 37.5 – 64.5% and 35.5 – 90% for Tudun Sarki and Basawa respectively. Herbs species common to Basawa sites include, Senna, Sporobolus pyramidalis, Calotropis procera, Sida acuta, Indigofera numlarifolia, Acanthospermum hispidium and Chamaecristi rotundifolia while those common to Tudun Sarki(ABU) include, Calotropis procera, Spermacoce radiata, Bracharia, Sida, Senna and Desmodium numlarifolia. Top soils in both sites were dominated by sandy clay and loam. Total nitrogen values were more in the surface horizons in both sites. Values of exchangeable bases were high, hence lower values of exchangeable acidity were recorded. In terms of number of species and Simpson’s index per quadrat, there is no significant difference (P< 0.05) in both experimental sites.