Yield and nutritive value of forage bermudagrasses grown using subsurface drip irrigation in the southern high plains

Bermudagrass [Cynodon dactylon (L.) Pers.] forages are potential alternatives to traditional row cropping in the Southern High Plains. Early persistence of certain bermudagrass selections and economic potential and nutritive value of known, improved cultivars in semiarid West Texas are uncertain. A 2-yr study was conducted to evaluate hay productivity and nutritive value of 10 cultivars and two selections of bermudagrass grown with subsurface drip irrigation. Grasses were irrigated with 312 mm of water from 1 May through 31 August in 2002 and 2003. Precipitation amounts during the growing season (May-September) were 195 and, 184 mm for 2002 and 2003, respectively. 'Tifton 85' yielded the highest total annual biomass (20.4 Mg ha(-1)) and resulted in high irrigation water use efficiency (IWUE; 65.2 kg ha(-1) mm(-1)). 'World Feeder' and 'Macho' performed poorly with respect to yield when compared with the other 10 grasses. Although Tifton 85 exhibited high acid detergent fiber (ADF; 349 g kg(-1)) and low total nonstructural carbohydrates (TNC; 93 g kg(-1)), in vitro dry matter disappearance (IVDMD) was greatest (622 g kg(-1)) when contrasted with the mean of all other cultivars. Yields were similar for sprigged and seeded types. Results indicate that several bermudagrass cultivars maintained high yields and adequate nutrition 2 yr after establishment and, based on IWUE, may be an economically sound alternative to the existing cotton (Gossypium hirsutum L.) monoculture in the region.