Impacts of industrial farming and common diets on the urban- and agro- ecosystems have been increasingly analyzed, improving insight into some of the negative consequences of food production. In particular, beef production has been linked to numerous challenges, such as climate change and water resource depletion. Although studies have identified benefits and tradeoffs associated with specific beef systems (e.g., grass- vs. grain-finished), there has been limited exploration of opportunities to improve these agroecosytems. Also lacking has been a discussion of how transitioning to alternate systems could affect farm profits or be incentivized.
The objective of this study was to compare environmental and societal implications of various farming systems that indirectly or directly include beef production. As conventionally managed corn-soybean farms are key to industrial beef production, we developed several hypothetical scenarios that involved a transition of corn-soy fields to grass-based grazing lands and/or diversified crop rotations. We used the Cropping Systems Calculator to model costs and savings in each scenario, and literature values to estimate impacts on soil N2O and carbon fluxes, fuel use, and grey and green water consumption.
Results/Conclusions
We found that integrating crop rotations and grazing into farms could be profitable for farmers while reducing fertilizer and fuel use, lowering soil N2O fluxes, and increasing soil C. The economic model, optimized for a ten-county region in the Chippewa River Watershed, MN (2014 prices) indicated that net returns were positive in response to different degrees of conversion of corn-soy fields to perennial pasture with intensively managed custom grazing. Conversion of additional crop acres to a four-year rotation was also possible while still earning profits, particularly when corn and soy yields were boosted in response to improved soil health. All scenarios were associated with climate change mitigation value from carbon sequestration, and reduced soil N2O and fuel use. When a social cost of carbon of $36/t was considered, the estimated social value of alternate systems exceeded the monetary value of average current conservation payments (from the USDA). While benefits were predicted at the farm-scale, scaling up would likely lead to changes in economic conditions (affecting profits) and to food production. While detailed analysis of these issues was outside the scope of the study, we discuss results in the context of potential scale-up scenarios.