Grass Establishment on Eroded Soil in A Semiarid African Reserve

Abstract

An area typical of bare overgrazed land in the semi-arid Machakos African Land Unit has been used for experiments on restoration of fertility and on land management. A 32-acre factorial experiment on methods of grass esfaB1ishment is described. Sown and planted grasses were tested on land prepared by various cultivation treatments, and the first two years of grazing-yields are reported. Yields were substantially improved by ploughing, by manuring, and by the incorporation of manure in ridges. Ripping did not improve grass establishment or soil-moisture storage. In two drought years, 10·13 and 16.71 in. of rain respectively, the planting of grasses was more successful than sowing. In a year of very good rainfall sown grasses were rapidly established and gave yields equal to those of the planted species. Ridging was found to conserve available soil moisture for two months of dry weather. Grass roots increased the field capacity of the first 3 in. of soil, but did not, in 2 years, increase the volume of free-draining pore-space.