Location: Agricultural Systems ResearchTitle: Spring grazing winter cereals in Montana Author
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/26/2009
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: Winter wheat (Triticum aestivum L.) is widely utilized for winter pasture and grain production in the central and southern US plains. Under rainfed conditions in the northern Great Plains, winter wheat seldom achieves adequate fall biomass for grazing, and little is known about the impacts of grazing on subsequent forage or grain production. Field experiments were conducted to evaluate the impacts of grazing forage winter cereals at the vegetative (V), boot (B) and heading (H) stages of growth on subsequent hay yield, forage quality and grain yield. ‘Willow Creek’ forage wheat (2006, 2007 and 2008) and ‘TRICAL® 102’ triticale (X Triticosecale Wittmack) (2006 and 2008) were grown under rainfed conditions near Fort Ellis, MT. At each growth stage, replicated enclosures were grazed by yearling lambs (Ovis aries). The grazing cell locations were maintained, and forage biomass samples were taken in all plots at 14-day intervals until ungrazed plots reached physiological maturity at grain harvest. Biomass accumulation was very rapid from late May through June, 87 to 248 kg ha-1 forage dry matter (DM) per day. Forage DM yields of ungrazed winter wheat (4.0 to 13.2 Mg ha-1) and triticale (8.5 to 12.6 Mg ha-1) varied widely due to previous cropping sequence; crop fallow (2007 and 2008) and continuous re-crop (2006). Grazing beyond the V stage significantly (P < 0.05) reduced forage (by 48 to 93%) and grain yields (by 56 to 87%). At the V stage, winter cereals had high levels of crude protein (223 to 284 g kg-1), in situ DM disappearance (797 to 913 g kg-1), but had toxic levels of nitrate in 2008. Under rainfed conditions, 0.6 to 3.2 Mg ha-1 of high-quality forage would be available for grazing at the V stage with limited impact on subsequent hay yield.