Smallholder Productivity and Weather Shocks : Adoption and Impact of Widely Promoted Agricultural Practices in Tanzania

Food security in Tanzania is projected to deteriorate as a result of climate change. In spite of the efforts to promote agricultural practices to improve productivity and food security, adoption rates of such practices remain low. Developing a thorough understanding of the determinants of adoption and updating our understanding of the impacts of these technologies under the site-specific effects of climate change are crucial to improve food security. This paper addresses these issues by using a novel data set that combines information from two large-scale household surveys with geo-referenced historical rainfall and temperature data in order to understand the determinants of the adoption of a set of agricultural practices and their impacts on maize productivity under weather shocks in Tanzania. The specific practices analyzed are: maize-legume intercropping, soil and water conservation practices (SWC), the use of organic fertilizers, inorganic fertilizers and high yielding maize varieties. We fi nd strong complementarities between these practices both in terms of adoption and yield impacts. Long-run variability in rainfall decreases the adoption of fertilizers (both organic and inorganic) and increases that of improved seeds. Access to information and extension increase the incentives to adopt modern inputs as well as SWC. Farmers in areas where the cropping season's rainfall has been highly variable and temperature has been unexpectedly high have signicantly lower maize yields. SWC emerges as one of the most important practices in increasing yields with significant benefits by itself, in combination with other practices, under average weather conditions as well as under rainfall and temperature shocks. The shocks we analyze are expected to increase under climate change, underlining the importance of policies to buffer food security from the estimated effects of climate change. This paper contributes to evidence base to support policies to advance food security under climate change by underlining the importance of integrating site-specific analyses of climatic variables and their interactions with promoted practices in policy design and targeting