Vulnerability and Productivity Impacts of Farm-Level Interventions in the Brazilian Sertão

Monday, 15 December 2014
Jennifer A Burney, UCSD, La Jolla, CA, United States
The Brazilian Sertão exemplifies the complex dynamics between climate, land use, agricultural production, and food security presently playing out across the world's semi-arid tropics. Regional climate change in the past half-century is some of the most dramatic in the world -- +2 degrees average warming in many districts and -300mm rainfall. Crop yields have improved weakly or remained stagnant, in stark contrast with the rest of Brazil. As a result many smallholder farmers have increasingly turned to milk production, but they remain dependent on rainfall for forage growth. During droughts they thus face a choice between overgrazing and letting their cattle die. As a result, deforestation of the native Caatinga biome has been rampant, with estimates of 85% loss. We present the results of controlled tests, conducted with over one hundred farmers, of several on-farm interventions meant to boost on-farm productivity, reduce vulnerability to rainfall shocks, and lessen the incentives for deforestation. These interventions -- water cisterns, smallholder irrigation systems, balancing of animal feed ratios, and cultivation and use of palma forrageira as cattle feed -- are described and presented with results of their impact on productivity and vulnerability/resilience metrics. Estimates of larger-scale social benefits and future land-use change impacts are also discussed.