Seasonal Availability of Cool- and Warm-Season Herbage in the Northern Mixed Prairie

On the Ground • Variability in spatial and temporal patterns of herbage production is common in grasslands and can affect land uses, such as grazing. • Total herbage biomass in northern mixed grass prairie was similar on loamy and sand dune ecologic sites but varied in composition. • Cool-season grasses were uniformly produced throughout the grazing season, whereas warm-season grasses grew rapidly during August. • Litter conservation was important for increasing cool-season grass biomass, whereas warm-season grasses remained independent of litter. • Biomass and composition of herbage in the northern mixed grass varies spatially and intra-annually, affecting seasonal grazing opportunities for livestock .