Utilizing Switchgrass for Forage in the Southern Ozarks

Native warm season grasses have the potential for inclusion in forage programs in the southern Ozarks, but little is known about the management requirements for sustainable production.  Switchgrass is a native warm season grass with potential for use as a hay crop in the region but unlike tall fescue and bermudagrass, which are common forages in the Ozarks, little is known about the forage production of switchgrass.  Switchgrass may help livestock producers diversify their forage systems on marginal soils while also allowing flexibility in response to variations in forage quality, livestock markets, and drought. One of the keys to maximizing yield and quality of any annual or perennial forage is management, which includes applying the proper amount of nitrogen fertilizer to meet yield goals and the nutritive quality demands of different livestock classes.  

Multiple field plantings by the USDA-NRCS Plant Materials Program over the years and on a variety of soil types across the southern Ozarks have determined that the cultivar 'Alamo' is adapted and performs well in the region.  However, there is limited information on Alamo switchgrass response to N fertilizer on yield and quality in the southern Ozarks region. To answer this question, a 3-year field study was conducted by the USDA-NRCS Booneville, Arkansas Plant Materials Center and the Dale Bumpers Small Farms Research Center, Booneville, Arkansas in 2014 -2016.  Nitrogen fertilizer was applied to field plots of Alamo switchgrass at rates of 0, 75, 250, 225 and 300 lb/acre in two, equal split applications and harvested 2 times/year in early June and again in late July. The average forage yield was 2.5, 3.5, 4.5 tons/acre when fertilized with 75, 150 and 225 lb of N/acre/year, respectively.  The average crude protein ranged from 7 to 8% and the total digestible nutrients ranged from 50 to 54%.  The study results suggest applying a minimum of 75 lbs of N/acre/year, not to exceed 225 lb/acre/year, as a split application in the spring at the time of green up and again in early summer to Alamo switchgrass stands results in a low-input hay crop option for producers.

Full details of the study can be found at Switchgrass nitrogen fertility response and nutrient cycling in a hay system | Agronomy Journal (wiley.com) 

For additional information on specific species of plants mentioned, please see the USDA PLANTS  database. Technical information and guidance on the use of conservation plants to address resource concerns can be found on the Plant Materials Program website or contact the nearest Plant Materials Center or plant materials specialist.