A Review of Agroforestry Practices with an Introduction to the Arba Minch Slope Farming Project

Abstract

Agroforestry is the inclusion of trees or other woody perennial plants into agricultural systems, including crop and livestock production. It can also be seen as a combination of agriculture and forestry. While conventional large scale agriculture is mainly concerned with maximising short term yields, agroforestry has the objective of emulating natural ecosystems in order to realise a number of ecosystem services. Those include the protection of soil against erosion and water-logging, minimising evaporation of water from soil and plants by decreasing wind speed, water protection through deeper and more extensive root systems and increased biodiversity. Long term stability and productivity of agroforestry systems surpasses those of conventional monocultures or pasturelands, as they tend to be more resilient, but the establishment of trees on farmland comes with certain challenges. Until the trees start to pay off, several years or even decades might pass. The right combination of trees, crops and animals for the particular climate, soil type and desired outcomes has to be carefully selected, which is often hard to predict in terms of productivity and required management. Trees have the potential to become too dominant anddiminish yields of nearby cash crops or pasture grasses. Moreover, agricultural policies still tend to favour large scale conventional farming methods over alternative land management systems by selective provision of subsidies and lack of regulatory framework concerning agroforestry systems in particular.