6.4 Climatological Drivers of Double Cropping Expansion in the Brazilian Cerrado

Wednesday, 13 January 2016: 9:15 AM
Room 245 ( New Orleans Ernest N. Morial Convention Center)
Keith R. Spangler, Brown University, Providence, RI; and A. H. Lynch and S. Spera

The Amazon Basin has been subjected to unprecedented rates of land-use and land-cover change over the past several decades, primarily as a result of the expansion of agriculture. Enhanced rainforest conservation efforts toward the end of the twentieth century slowed deforestation of the Amazon but, in turn, increased demand for land repurposing in the adjacent Cerrado (savanna) region, where conservation regulations are less strict. In order to maintain yields while minimizing the need for additional land, farmers adopted a technique of “double cropping,” a form of agricultural intensification in which two rain-fed crops are planted successively on the same plot within a single growing season. While this practice is thought to confer numerous socioecological benefits, including increased cost-effectiveness and reduced land degradation, the physical and social drivers affecting the spatial distribution of its implementation are not well understood. Presented here are findings from a statistical evaluation of selected factors associated with the expansion of double-cropped agriculture across the Brazilian Cerrado for the growing years from 2003-2012. This study assesses data from: (1) MODIS 13 Enhanced Vegetation Index product for phenology-based landscape definitions; (2) TRMM 3B42v7 satellite for precipitation trends; (3) soil maps from the Brazilian Ministry of Agriculture, Livestock, and Food Supply; and (4) crop prices from the Food and Agriculture Organization of the UN. Our analyses demonstrate statistical significance between double cropping in the Cerrado and specific characteristics of the seasonal rainfall regime. This provides strong evidence to support the claim that the decision to utilize double cropping is driven in part by local climate. In the context of global climate change, this association is particularly salient not only for the long-term sustainability of Brazilian agriculture, but also for regional forest and Cerrado conservation efforts. While no study of an open socio-ecological system can encompass all possible drivers and consequences of land use decision-making, the results from this inquiry have utility in informing probabilistic assessments of future land-use and climatic changes in this vast, ecologically sensitive region.
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