Forecasting Unintended Consequences of Grassland Conversion
March 18, 2016
This column was written collaboratively by Roger Gates, Professor & SDSU Extension Rangeland Management Specialist; Ben Turner, Assistant Professor, Department of Agriculture, Agribusiness & Environmental Sciences, Texas A&M University-Kingsville; Melissa Wuellner, Assistant Professor, Department of Natural Resource Management; and Barry Dunn, South Dakota Corn Utilization Council Endowed Dean of the SDSU College of Agriculture & Biological Sciences, SDSU Extension Director.
Continuing implementation of the 2014 U.S. Farm Bill, which includes programs such as SodSaver and policies such as conservation compliance (restraining cultivation on highly erodible or marginal lands), provides incentives to enhance conservation of grasslands.
However, these policies will likely only slow, rather than reverse, recent trends of expansion of cultivation for crop production into existing grasslands. Driven by economics, policy, and social shifts in rural America, this is certainly a complex problem worthy of our ongoing attention.
Systems thinking, which combines both qualitative (descriptive observation) and quantitative (numerical, requiring measurement) data with computer simulation, is a methodology for investigating and interpreting complex problems.
Using information from farmers and ranchers across South Dakota, combined with USDA's National Agricultural Statistics Service (NASS), Natural Resource Conservation Service and U.S. Census Bureau data, SDSU investigators developed a systems model to forecast land use change across the northern Great Plains (SD, NE, ND, WY, MT).
Soil Environmental Risk (SER) was also assessed at the regional level based on varying degrees of cultivation intensity across differing land use qualities. This model was used to test and compare public policy and economic scenarios to identify favorable future conditions (Figure).
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Under the 2012 'base-case' scenario, where no policy changes occurred, an additional 9 million acres would be converted away from grassland by 2060, while Soil Environmental Risk (SER) would increase from 2.6 to 4.29 (or 65 percent).
Soil Environmental Risk
Eliminating the Conservation Reserve Program (CRP), for which budget constraints continue to limit acreage enrollments, led to an increase of almost 12 million acres by 2060 with an associated increase in Soil Environmental Risk to 5.2 (an increase in 100 percent).
For reference, estimated Soil Environmental Risk values during the Dust Bowl ranged between 5 and 10.
Increasing crop insurance premium subsidies (CIPS) to 95 percent of the rate covered also caused increased projected Soil Environmental Risk.
Reduced financial risk led to increased Soil Environmental Risk. Not all of the scenarios tested were so alarming. More stringent conservation compliance would essentially keep land use at today's levels, while policies aimed at increasing participation of younger individuals in livestock agriculture would result in similar conditions but with enhanced rural community-resilience. Integrating livestock with crop production provided the most noticeable reduction in Soil Environmental Risk, due to higher demand for grass acres and additional crop diversity to enhance grazing opportunities.
The systems approach provided some of the first forecasts for both land-use change and associated negative impacts of grassland loss in the region.
Although gains have been made in conservation policies, more will be needed if stakeholders and policy makers want to avoid serious consequences comparable to the Dust Bowl era.