PSXI-19 Impact of toxic-infected tall fescue renovation strategies on second-year hay yield, botanical composition, and nutritive value

Abstract Renovating toxic-infected tall fescue (Lolium arundinaceum) (TF) pastures to novel endophyte tall fescue (NE) is a solution to mitigate the negative associated effects of toxic fescue in beef cattle. However, beef cattle producers are uncertain of the payback period for costs associated with renovation techniques in terms of farm profitability and agronomic performance. In 2018, three renovation strategies were implemented in a randomized complete block design in Bahama, NC. Strategies included: 1) control (C), 2) renovation to NE after one season of a single specie cover crop (1-SM), 3) renovation to NE after three seasons of a single specie cover crop (3-SM), and 4) renovation to NE after three seasons of a multi-specie cover crop (3-CM). Each treatment plot (0.81 ha) was evaluated for botanical composition and hay was harvested in May and August of 2020. Round bales from each treatment were weighed to determine yield and core sampled to determine nutritive value. Data were analyzed using proc GLIMMIX of SAS v9.4. Combined forage yield was greater (P = 0.0226) for 3-CM (8,816 kg/ha) compared to 3-SM (7,191 kg/ha) and C (6,920 kg/ha), but did not differ from 1-SM (7,775 kg/ha). Crude protein concentration was greater (P = 0.035) for C (10.2%) in comparison to 3-SM (9.35%) in harvest 1, but was not different (P = 0.93) in harvest 2. Percentage of fescue in the sward was greatest (P = 0.0002) for 3-SM and least for C (84.9 and 62%, respectively). Similarly, presence of undesirable plants was greater (P < 0.0001) for C (37.5%) than 1-SM, 3-CM and 3-SM (23.7, 15.2 and 12.7%, respectively). Percentage of bare ground did not differ among treatments (P = 0.31). Data suggest agronomic performance for 3-CM and 3-SM was improved compared to C in years following pasture renovation.