Herbage Nutritive Value of Tall Fescue-Bermudagrass Binary Mixtures Fertilized with Combinations of Nitrogen Fertilizer and Poultry Litter.

Year-round forage production is feasible in much of the southeastern USA through utilization of cool- and warm-season forages. This study determined if productivity and nutritive value in binary mixtures of tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] and bermudagrass [Cynodon dactylon (L.) Pers.] could be improved through application timing of poultry litter and fertilizer N to coincide with seasonal growth activities. Two tall fescue cultivars, ‘Flecha MaxQ’ (summer-dormant) and ‘Jesup MaxQ’ (summer-active) were drill-seeded in 2007 into established swards of ‘Russell’ and ‘Tifton 44’ bermudagrass. Three seasonal N treatments were each comprised of 8.6 Mg litter ha^-1 (as-is moisture basis) split into two applications per season with additional 168 kg N ha^-1 split into three applications per season. Samples of mixed herbage were obtained in April, May, July and August 2009 and 2010 and analyzed for crude protein (CP, by dry combustion), acid detergent fiber, neutral detergent fiber and in vitro true digestible dry matter (ADF, NDF, and IVDDM, respectively, by NIRS procedures) to assess treatment effects on nutritive value. In general, nutritive value was greatest for Jesup-Tifton 44 mixture, based on low ADF and high CP and IVDDM. As compared to Jan/Mar seasonal N treatment that applied litter and fertilizer N in January–July, applying N before April significantly (P < 0.01) enhanced yield performance of mixed herbage in April and May and herbage IVDDM harvested in either July (603 vs. 629 g kg^-1, 2 yr average) or August (618 vs. 660 g kg^-1). Results suggest application timing of poultry litter and N to favor growth of the cool-season grass may benefit nutritive quality of tall fescue-bermudagrass production systems.