Acacia Trees Enhance Soil Nitrogen That Influences Grass Crude Protein In African Rangelands

Abstract

The study found out the impact of acacia trees on soil nitrogen and how this nitrogen consequently influences the grass crude protein in Sanga rangeland. Four 100×100m plots were randomly selected in a vast area, five acacia trees and five open areas randomly identified in each plot. A soil and pasture sample were collected from each acacia tree and in open area. Samples were analyzed by Kjeldahl's method to determine percentage soil nitrogen and grass crude protein. The results were subjected to analysis of variance using MINITAB 14 statistical software. Percentage soil nitrogen and grass crude protein significantly differed between under acacia and away from acacia with P=0.001 and P=0.007 respectively. Both soil nitrogen and grass crude protein were higher near acacia than in the open area. We suggest that the co-existence between grasses, acacia trees and also herbivores at an advanced level should be area of interest to livestock farmers and rangeland managers. Natural soil fertility replenishment in African rangelands is partly influenced by acacia trees which have also gone ahead to determine the nutritional quality of ground grass species that are the basic source of food to rangeland herbivorous and omnivorous animals. Finding out the approximate tree population and spacing required for optimum rangeland productivity and the interest to know the acacia species fixing more nitrogen than the others are areas for further research. This can help to understand the species to be kept in the rangelands and in what proportions.