Winter Annual Legumes Seeded Into Bermudagrass: Production, Nutritive Value, And Animal Preference

Overseeding cool-season annual legumes into bermudagrass [Cynodon dactylon (L.) Pers.] offers an economical solution to pasture shortage experienced by beef cattle (Bos spp.) farmers during winter on the southeastern Coastal Plain of the USA. Using Austrian winter peas [Pisum sativum var. arvense (L.) Poir.], 'Dixie' crimson clover (Trifolium incarnatum L.), 'Yucchi' and 'Apache' arrowleaf clover (T. vesiculosum Savi), and 'AU Merit' hairy vetch (Vicia villosa Roth.) in replicated complete blocks (four replicates in each of two growing seasons), our objectives were to (i) determine the nutritive value of forage provided by several legumes as they mature; (ii) evaluate legume impact on the nutritive value of subsequent bermudagrass hay harvests; (iii) obtain estimates of the quantity of N they potentially add to the system; and (iv) evaluate the preferences of grazing cattle for the various legumes. All legumes improved early-spring dry matter (DM) yield compared with control plots without overseeding (3310 vs. 1120 lb/acre for legumes and control; P < 0.01). Legumes increased the crude protein (CP) content of bermudagrass hay harvested during the subsequent growing season (14.1, 14.8, 13.7, 14.8, and 12.0% for crimson, vetch, peas, arrowleaf, and control, respectively; P < 0.01); however, peas and arrowleaf reduced hay DM yield (P = 0.04). Across species, legumes added approximately 89 lb/acre N to the system by fixation, and overseeding offered a potential addition of 64 grazing days/acre (1200-lb cows). Legumes improved the potential removal of both N and P from the system, and cattle readily consumed the legumes. Overseeding may have the potential to reduce N fertilization and lengthen grazing season; however, with added seed costs, it may not improve profitability.