A Systems Approach to Biodigester Evaluation: Analyzing Bioresources to Asses Farm Integration in the Arsi Zone, Ethiopia
Mia Schoeber1, Bernhard Freyer1, Gerold Rahmann2
1University of Natural Resources and Life Sciences (BOKU), Dept. of Sustainable Agricultural Systems, Austria
Smallholder farms in the Arsi zone, Ethiopia, have an average size of 3.3 ha, are situated at an altitude of around 2200 m with annual rainfall between 800-1300 mm and temperatures between 10-25 °C. Agriculture in this region has a high potential, but is limited by water logging, surface runoff, high soil erosion and decreasing soil fertility. Traditionally, livestock manure on smallholder farms is primarily used as a fuel and the remainder as fertiliser on fields. Competition between these two applications can be eliminated by biodigesters, in which manure is transformed to biogas utilised for light and cooking, and bioslurry, a nutritious organic fertiliser. In this study we analyze, how far biodigesters as part of the farming system can cover farm own energy demand and increase nutrients and organic matter supply in the form of bioslurry/compost to the crops to increase farm income and the sustainment of soil and future crop productivity. Bioresource management of 47 farms have been analyzed, and mainly qualitative data collected to identify opportunities and constrains of biodigester use.
Keywords: Arsi zone, Ethiopia, bioresources, household biodigester, integrated smallholder farm
Contact Address: Mia Schoeber, University of Natural Resources and Life Sciences (BOKU), Dept. of Sustainable Agricultural Systems, Vienna, Austria, e-mail: miaschoeberhotmail.com