Submitted to: Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: September 15, 2005
Publication Date: November 10, 2005
Citation: Rao, S.C., Northup, B.K., Phillips, W.A., Mayeux, H.S. 2005. Using cool-season legumes to extend the forage production season of bermudagrass pastures in the southern plains [abstract]. Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting. Paper No. 3172. Interpretive Summary: Abstract Only.
Technical Abstract: Nitrogen fertilizers are essential to maximize productivity of monocultures of perennial grasses. Including legumes in such pastures can improve seasonal distribution of high quality forage, and reduce N fertilizer requirements. This study determined if incorporation of annual cool-season legumes could lengthen the spring forage production period of bermudagrass (Cynodon dactylon) pastures. Treatments applied to experimental plots included inter-seeding of grasspea (Lathyrus sativa L. cv. AC-Greenfix) or lentil (Lens culinaris Med. cv. Indianhead) in mid-March with 60 kg ha-1 P205, or application of 0, 45, or 90 kg ha-1 N. Forage samples were clipped from random (n=3) 0.25 m-2 quadrates on five sampling dates (May 1 to July 15) annually during 2001-2003, and used to define total biomass and concentrations of nitrogen (N) and in vitro digestible dry matter (IVDDM). Significant (P<0.05) 2-way interactions were noted between sampling date, years and treatments for total biomass, as were 3-way interactions for N and IVDDM. End-of-season biomass of plots inter-seeded with grasspea (5550 kg ha-1) was intermediate to biomass of plots receiving 45 or 90 kg ha-1 N (5305 and 7785 kg ha-1, respectively). Average forage N and IVDDM concentrations of the bermudagrass-grasspea mixture were 34 and 6% higher, respectively, than bermudagrass treated with 90 kg ha-1 N. End-of-season biomass of the lentil treatment was similar to unfertilized controls, but N and IVDDM concentrations were intermediate to 45 and 90 kg ha-1 N treatments. Inter-seeding grasspea into bermudagrass pasture can produce sufficient forage in spring to allow the start of grazing one month earlier, and improve forage quality through mid-summer.