Determinants of inorganic fertiliser use in the mixed crop-livestock farming systems of the central highlands of Ethiopia.

Increased use of inorganic fertilisers is believed to be fundamental to addressing the low and declining soil fertility and improving food security in sub-Sahara Africa (SSA). Despite notable improvements in the supply of inorganic fertilisers and supporting services such as extension and credit, use of inorganic fertilisers among smallholder farmers remained disappointingly low. The objective of this study was to determine key factors responsible for use of inorganic fertilisers in the mixed crop-livestock farming systems in the central highlands of Ethiopia. Heckman’s two-step procedure was used to analyse the variables. Education level of the head of the household, number of livestock owned, number of plots owned, land tenure, access to credit and extension, agroecology and manure use influenced both the likelihood of adoption and intensity of inorganic fertiliser use. Continued land redistribution in the already degraded and land scarce highlands further undermine sustainable farming and increase nutrient mining. On the other hand, shrinking plot size as a result of repeated plot subdivisions may induce current users of inorganic fertilisers to use more nutrients per unit of land in an attempt to raise productivity. This positive effect, however, may be more than offset by the negative effects exerted by plot distance, thus leading to nutrient mining.Key Words: Adoption, Heckman two-stage, land tenure, manur