Stockpiling Perennial Warm-Season Forage Grasses in East-Central Mississippi.

Stockpiling of a warm-season perennial grass for grazing during fall and winter months is a management practice that can lower livestock production costs and extend the grazing season.  Two seeded bermudagrass [Cynodon dactylon (L.) Pers.] and two bahiagrass (Paspalum notatum Flugge) cultivars were compared in a small plot field trial in east-central Mississippi.  Each cultivar had four nitrogen treatments (0, 28, 56, and 84 kg N a^-1) with four harvest dates (30, 60, 90, and 120 d after N application) during the fall and winter of 2015 and 2016.  Plots were sampled to monitor accumulated dry matter (DM), nutritive value [crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF)], sward heights, normalized differential vegetation index (NDVI), and leaf area index (LAI).  Total digestible nutrients (TDN) and relative feed quality (RFQ) were calculated based on nutritive values.  In 2015, cumulative forage biomass was less than 3000 kg DM ha^-1 for all cultivars.  CP values for all cultivars in 2015 were greater than 110 g kg^-1 for all harvests and increased with time.  Bahiagrass cultivars generally had greater CP than bermudagrass cultivars, with all cultivars remaining above minimum requirements for mature, non-lactating pregnant beef cows (70-80 g kg^-1).  ADF and NDF increased with time for all entries, with the largest monthly increase occurring in the harvest following a killing frost.  TDN and RFQ values suggest energy requirements for beef livestock cannot be met with these standing forages, thus necessitating high energy supplements.  Data for 2016 has yet to be collected and analyzed*.

*Data and statistical analyses for 2016 will be finalized prior to final poster presentation in February 2017.