Eco-certification and greening the Brazilian soy and corn supply chains.

Garrett et al 's recent letter (2013 Environ. Res. Lett. 8 044055) shows the trade value of Brazil's production of non-genetically modified (GM) crops, and argues that production for this niche market laid the foundation for the expansion of a variety of non-GM and eco-certification systems. We argue that the conditions underlying the development and perpetuation of the non-GM certification systems are transient. The expansion of soy production has dampened the conditions that promoted the dominance of non-GM soy in the region. The state at the heart of the production of conventional soy, Mato Grosso, already has transitioned to almost 90% GM soy in the most recent agricultural season. The continued viability of eco-certification systems depends on strengthening institutions on the demand side, and ensuring farm-level costs on the supply side match price premiums reaching the farm level.