|Mayeux Jr, Herman|
Submitted to: Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 9/15/2003
Publication Date: 11/1/2003
Citation: Rao, S.C., Mayeux, H.S. 2003. Performance of forage soybean lines in the Southern Great Plains [abstract]. Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting. Paper No. C06-rao287249-poster.
Technical Abstract: Pasture for livestock is often in short supply during the late summer in the southern Great Plains. The objective of this study was to compare seasonal forage production patterns, forage quality, and grain yield of three recently developed forage soybean cultivars ('Donegal', 'Derry' and 'Tyrone') to the commonly grown grain soybean cultivar 'Hutchinson'. Inoculated seed were planted at 60 kg/ha in rows (10 m long) with row spacing of 60 cm, in June 2001 and 2002 after no-till winter wheat was harvested. Whole plant samples were collected on six sampling dates from 52 days after seeding (DAS) to 120 DAS. At the last sampling date, forage cultivars produced 43 percent more leaf biomass and 61 percent more stem biomass compared with grain soybean. Grain soybean initiated reproductive growth 15 days earlier than forage soybeans resulting in lower leaf and stem yield. Forage quality of whole plants (N concentration and dry matter digestibility) were similar across all cultivars. Grain yields of forage soybeans were 29 percent lower than grain soybeans at 105 DAS, but prolonged growth of forage soybeans produced 12 percent more grain at 120 DAS. Nitrogen concentration of forage soybean grain at 105 and 120 DAS were 3 and 1.3 g N/kg greater than the grain soybean. These results suggest that forage soybeans have the potential to provide higher leaf and stem biomass at later growth stages when other forages are less productive.