By Scout Nelson
According to research led by South Dakota State University, nearly 80 years of grazing records from the Cottonwood Field Station in western South Dakota are helping guide future rangeland management decisions. These long-term studies provide rare insight into how grazing intensity affects prairie ecosystems over time.
Beginning in the 1940s and 1950s, early researchers carefully recorded plant growth, species mix, forage production, and pasture condition by hand. These notes captured valuable details about how mixed grass prairie responds to different grazing pressures. Today, SDSU researchers from natural resource management, animal science, and university archives are working together to digitize these handwritten records and compare them with modern data.
The digitization process uses modern technology to scan and convert old field notes into usable digital records. Once processed, the data is standardized so it can match current plant names, soil types, and measurement units. This allows researchers to combine historical records with recent data collected from 2000 through 2023, creating a continuous dataset that spans more than eight decades.
The long-term study includes three consistent grazing levels: light, moderate, and heavy. Results show clear trends. Light grazing supports taller cool season grasses like western wheatgrass. Moderate grazing maintains a healthy mix of grass species and improves overall forage production. Heavy grazing reduces taller grasses and favors short grass species such as blue grama and buffalograss, which survive frequent grazing but produce less forage.
These findings help explain how weather changes, drought, and grazing pressure work together over time. Short studies cannot capture these patterns, but long-term records clearly show how land responds year after year.
For today’s ranchers and land managers, this information supports better planning. It helps adjust stocking rates, predict plant changes after drought, improve forage planning, and protect long-term land health while staying profitable.
Because South Dakota’s prairie shares traits with much of the Northern Great Plains, these lessons extend beyond the state. By preserving and studying this history, researchers ensure past knowledge continues to support strong, resilient rangelands for the future.
Photo Credit: gettyimages-imaginegolf
Categories: South Dakota, General