Grass-cast: an experimental grassland productivity forecast

TitleGrass-cast: an experimental grassland productivity forecast
Publication TypeConference Paper
Year of Publication2020
AuthorsKramer L, Elias EH, Peck DE, Parton W, Hartman M, Derner J.D, Smith W, Fuchs B
Conference NameSociety for Range Management Meeting Abstracts
ARIS Log Number382247

Every spring, ranchers face the same difficult challenge—trying to guess how much grass will be available for livestock to graze during the upcoming growing season. Since May 2018, an innovative Grassland Productivity Forecast or “Grass-Cast” has been helping producers in the Great Plains reduce this economically important source of uncertainty. This experimental grassland forecast is the result of collaboration between the U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS), Climate Hubs, and Natural Resources Conservation Service (NRCS); the National Drought Mitigation Center (NDMC); Colorado State University and the University of Arizona. Grass-Cast provides land managers with an indication of what productivity is likely to be in the upcoming growing season relative to their own county’s history. Grass-Cast uses over 30 years of historical data on weather and vegetation growth—combined with remotely-sensed NDVI data and seasonal precipitation forecasts—to predict if rangelands in individual ~6 mile x 6 mile areas are likely to produce above-normal, near-normal, or below-normal amounts of vegetation. The program’s accuracy improves as the growing season unfolds, so it should be consulted more than just once during the growing season. The maps are updated every two weeks to incorporate newly observed weather data and emerging trends in grazing conditions. This tool can help rangeland managers better anticipate drought and prepare for shortages in grazing resources while also providing a view of rangeland productivity in the broader region to help with larger-scale decision making, such as determining where grazing resources might be more plentiful if their own region is at risk from drought. Grass-Cast is currently available to producers in the Great Plains and the Southwest (NM and AZ) Regions of the U.S.