Assessing Ecological Resilience of Smallholder Farms in the Brazilian Cerrado.

The Cerrado is the largest savanna in South America and a biodiversity hotspot. Recently, the biome has become a center for export agriculture, accounting for 60% of Brazilian soybean production. The rapid industrialization of agriculture in Brazil’s Center-West is contentious: despite high yields, extensive deforestation of the native savanna ecosystem, and associated biodiversity losses and environmental degradation, have called into question the ecological resilience of large-scale commodity production. At the same time, smallholder and organic agriculture coexist alongside export commodity farms in Cerrado states such as Mato Grosso, contributing to household and community nutrition. In a one-year study in three farming communities in Mato Grosso, we pilot tested an indicator framework to assess ecological resilience of these alternative production systems, which are highly understudied in this region. We surveyed 55 households about their farming systems and management practices, and analyzed soil samples from 46 farm fields. Farms were 30 hectares on average and produced a diverse range of crops including banana, cassava, papaya, corn and vegetables. Managing soil fertility is a critical challenge on farms with low or no-external inputs, particularly in this tropical region, which has highly weathered Oxisols and Ultisols with high phosphorous binding capacity. Agroecological farmers who were marketing vegetable and fruit crops through a federal public procurement program had significantly greater agrobiodiversity, organic fertility amendments such as manure, plant-available soil phosphorous, and particulate organic matter (POM) pools compared to farmers selling crops through other market outlets. Fields with organic fertility inputs also had greater nitrogen content in the POM fractions, indicating greater capacity for mineralization to supply nutrients to crops. The indicator framework highlighted tradeoffs and synergies among the multiple goals of smallholder farms, and potential leverage points for scaling up more resilient food systems in this ecologically threatened biome.