Frontiers in Sustainable Food Systems (Mar 2021)
Native Grasslands at the Core: A New Paradigm of Intensification for the Campos of Southern South America to Increase Economic and Environmental Sustainability
Abstract
Extensive livestock production in southern South America occupies ~0.5 M km2 in central-eastern Argentina, Uruguay and southern Brazil. These systems have been sustained for more than 300 years by year-long grazing of the highly biodiverse native Campos ecosystems that provides many valuable additional ecosystem services. However, their low productivity (~70 kg liveweight/ha per year), at least relative to values recorded in experiments and by best farmers, has been driving continued land use conversion towards agriculture and forestry. Therefore, there is a pressing need for usable, cost effective technological options based on scientific knowledge that increase profitability while supporting the conservation of native grasslands. In the early 2000s, existing knowledge was synthesized in a path of six sequential steps of increasing intensification. Even though higher productivity underlined that path, it was recognized that trade-offs would occur, with increases in productivity being concomitant to reductions in diversity, resilience to droughts, and a higher exposure to financial risks. Here, we put forward a proposal to shift the current paradigm away from a linear sequence and toward a flexible dashboard of intensification options to be implemented in defined modules within a farm whose aims are (i) to maintain native grasslands as the main feed source, and (ii) ameliorate its two major productive drawbacks: marked seasonality and relatively rapid loss of low nutritive value-hence the title “native grasslands at the core.” At its center, the proposal highlights a key role for optimal grazing management of native grasslands to increase productivity and resilience while maintaining low system wide costs and financial risk, but acknowledges that achieving the required spatio-temporal control of grazing intensity requires using (a portfolio of) complementary, synergistic intensification options. We sum up experimental evidence and case studies supporting the hypothesis that integrating intensification options increases both profitability and environmental sustainability of livestock production in Campos ecosystems.
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