An Acacia-based design for sustainable livestock carrying capacity on irrigated farmlands in semi-arid Africa

Abstract

Multiple land use designs are becoming increasingly necessary in semi-arid Africa as growing populations focus numerous production systems onto spatially limited arable lands. Engineering distinct land uses into a single area ideally requires that land use components compliment each other, and operate in predictable magnitudes. Quantitative evaluations of components to be included in multiple land use designs are necessary to determine both how components would 'fit' together, and how these would serve populations participating in distinct production systems. With data gathered in Somalia, this study considers a design in which fodder producing trees and irrigated agriculture could be integrated. Following a discussion of the benefits of such an integration, this analysis focuses on a quantitative examination of potential livestock carrying capacity from Acacia albida trees in an irrigated area. Comparisons are made with observed livestock numbers in order to determine if such a design could accommodate the seasonal influx of nomadic herds. The land use elements that comprise carrying capacity are themselves examined to see which elements might be managed to offset or take advantage of those which are not easily managed.

Pastoralist Resource Use and Access in Somalia: A Changing Context of Development, Environmental Stress and Conflict

“…Browsers in Somalia (camels and goats) are hardier than grazers (cattle and sheep), have wider forage preferences, and can be watered less. The protein provided by forage tree and bush species allow greater utilization of protein deficient grasses and crop residues, which otherwise would be consumed less and with less benefit to livestock (Unruh 1993c:32 and the references cited therein). A decrease in browsers and the vegetation to sustain them can make a pastoral livelihood based on extensive livestock production more vulnerable to drought.…”

The Role of Land Use Pattern and Process in the Diffusion of Valuable Tree Species

“…The tree does not compete with crops because it sheds its leaves and becomes dormant during the rainy season. Cultivators do not fell the tree because crop yields are frequently found to be higher in association with this species (Miehe 1986;Felker and Bandurski 1979;Radwanske and Wickens 1967;Le Houerou 1980;Unruh 1993 and the references therein). Thus this tree survives and spreads by a specific spatial and temporal combination of pastoralism and rainfed agriculture to become a dominant in certain man-made landscapes (Harlan 1975;Poschen 1986).…”