The Role of Extension and Sustainable Soil Management in Smallholder Agriculture-Evidence from Ethiopia

Rising demand for agricultural commodities coupled with population growth, climate change, declining soil fertility, environmental degradation and rural poverty in the developing world call for strategies to sustainably intensify agricultural production. Sustainable intensification refers to increasing production from the same area of land while reducing its negative environmental consequences. Most of the adverse conditions are particularly prevalent in Sub-Saharan Africa (SSA), where rates of undernutrition are the highest worldwide, while agricultural productivity is still far below global averages. An important factor in explaining productivity deficits among smallholders in SSA is the slow adoption of new agricultural technologies. Recently, governments and international donors especially concentrate on the promotion of ‘system technologies’, i.e. packages of technologies that should be applied jointly due to synergistic effects. Yet, evidence shows that farmers delay in particular the uptake of system technologies, and tend to scatter practices across plots instead of combining them on the same plot. Hence, analyzing how to effectively enhance the adoption of technology packages is crucial, but still understudied. In addition, comprehensive studies on the plot- and household level effects of system technologies that use micro data from farmer surveys are still scarce when it comes to impacts beyond traditional outcomes, such as crop yields and income, but important to understand the consequences of adoption for farmers.

This dissertation addresses these gaps by studying the adoption and effects of ‘Integrated Soil Fertility Management’ (ISFM). ISFM is a system technology comprised of a set of sitespecific soil fertility practices which should be applied in combination. Its core is the integrated use of organic and inorganic fertilizers with improved seeds. Practices should be adapted to local conditions, accompanied by a general improvement of agronomic techniques and, depending on the context, by other technologies such as crop rotation, agroforestry or reduced tillage. The general aim of ISFM is an improvement of the soil’s fertility by replenishing its nutrient stocks and organic matter level. Enhanced soil fertility is likely to improve food security, incomes, and ultimately, livelihoods of the rural population depending on small-scale agriculture. In addition, healthier and more fertile soils can contribute to restoring and conserving natural resources by providing crucial ecosystem services, such as the storage of soil carbon, erosion control and the prevention of further deforestation. Thus, they can make an important contribution to the sustainable intensification of smallholder agricultural systems. However, ISFM commonly also goes along with increased demand for capital and labor, which often prevents smallholders from adopting it. In addition, ISFM is considered knowledge-intensive, as combining several practices and adapting them to local conditions requires at least a basic understanding of biological processes.

Against this background, the dissertation addresses two broad research objectives: Firstly, to assess the role of ‘farmer-to-farmer’ and non-traditional forms of agricultural extension to enhance knowledge and adoption of ISFM as a pathway to sustainable intensification. And secondly, to assess the productivity and welfare implications of adopting ISFM practices at the plot and household level. The thesis comprises three essays. The first essay concentrates on knowledge and adoption of ISFM as a complex agricultural technology, while the second and third essay analyze the effects of ISFM at the plot, respectively household level. All three essays build on primary data collected among 2,382 farm households in the three Ethiopian regions Amhara, Oromia and Tigray. The research was carried out in cooperation with the ‘Integrated Soil Fertility Management Project’ (ISFM+ project) of the German Agency for International Cooperation (GIZ), launched in 2015 in 18 districts in the three highland regions.