In the true prairie region, spring burning of big bluestem stands that have not been burned within the past few years almost always results in increased yields. Big bluestem rapidly produces large amounts of foliage following fire. When the fire interval is greater than about 5 years, bluestem prairie becomes unproductive because the large accumulations of standing dead material stifle growth. However, fires occurring more frequently than every 2 years will probably lower biomass production. Postburn herbage production indicates that the season of burning, the amount of annual precipitation the area receives, and site conditions greatly influence big bluestem's response to burning.
Response is somewhat variable though, and dependent upon site characteristics.
42.4 43.4 2.0 15.1 23.0 Fires that occur during the summer cause the most harm to big bluestem. Measurements taken the following August showed that productivity was within the seasonal normal range. Late spring is the best time to burn big bluestem stands. The later in the spring burning occurs, just prior to the emergence of new growth, the greater the postburn herbage production will be. Regardless of season of burn, however, soil moisture content is consistently lower in burned areas than in unburned areas.