Economic Feasibility and Ecosystem Services Delivery of Grass-N and Legume-Forage Systems in Southern US.

Cool season forage species play an important role on extending the grazing season on livestock production systems in Southern US. Thus, the soil coverage and returning of nutrients to the system during this period contributes to optimize ecosystem services delivered. The objective was to determine feasibility of use of cool-season species in Southern US and their contribution to nutrient cycling. Treatments were all combinations of two forage systems and two defoliation methods replicated three times. The warm-season component was ‘Florigraze’ rhizoma peanut (Arachis glabrata) for the legume system and ‘Tifton-85’ bermudagrass (Cynodon spp.) for the grass system. Both systems were overseeded in fall with rye (Secale cereale) and ryegrass (Lolium multiflorum), and the legume system also was overseeded with crimson (Trifolium incarnatum) and red clovers (T. pratense). Grass-N plots received 30 kg N ha^-1 after each winter defoliation event, respectively. The estimation of seed and fertilizer costs will be done. Then, herbage mass and accumulation for grazed plots will be determined by double-sampling, and for hay plot by harvesting a sample with sickle bar mower. The return of nutrients to the system will be determined by residual litter biomass collected on the end of the season, and analyzed for C and N concentration by dry combustion. The results will be included on the further edition of this abstract.