Winter Pea and Lentil for Forage in Crop-Livestock Cropping Systems in Montana.

Traditional Australian ley farming system utilizes an annual legume (black medic, Medicago lupulina L.) pasture in rotation with a cereal crop (wheat, Triticum aestivium L.) and livestock graze on the legume pasture before it is terminated for planting the cereal crop. This system may provide some benefits in Montana integrated crop-livestock systems due to rising nitrogen and fuel prices. A survey of 4200 Montana farmers and ranchers indicated that about 43% of Montana producers had both crops and livestock in their operations in 2007.  Although medic was found to be agronomically unsuitable in Montana dryland cropping systems, alternative grazed legume crops appear to have some potential for incorporation into a wheat-based system. A project was carried out in central Montana to evaluate the potential of winter pea (Pisum sativum L.) and lentil (Lens culinaris L.) as forage for haying or grazing, and to investigate the benefits (including N benefit) of the pea and lentil for subsequent wheat in rotation. On average winter pea and lentil produced approximately 3000 and 2000 kg ha^-1 of hay, respectively. An economic analysis was performed and the estimates of nitrogen and haying or grazing benefits of the pea crop appear to offset the seed and machinery operating costs for peas. The nitrogen benefit from peas reduced, but did not completely eliminate the amount of urea that needed to be applied for a subsequent wheat crop.