Evaluation of Multiple Species for Use As Cover Crops in Dryland Production in Montana.

A statewide investigation (6 locations) of cover crop species was conducted to determine the best candidates for use in fallow replacement strategies for dryland crop production in Montana to improve soil qualities and provide forage for livestock. Species included 6 grasses, 8 legumes, 6 broadleaves, and 4 polycultures. Crops were planted at two timings, early April and late May, providing opportunity for both cool- and warm-season species to produce maximum growth. Treatments were arranged in randomized complete blocks replicated at each location. All species at both establishment timings were terminated at flowering of the annual grasses within the group. Total above ground biomass (AGB) was determined at termination. Nutrient profiles in terms of crude protein, ADF, NDF, TDN, NEL, NEM, NEG, and nitrate content were determined on subsamples to evaluate feed value. Values for AGB ranged from 0.0 to 4.1 Mg ha^-1 with warm season species averaging 1.6 Mg ha^-1 while cool season species averaged 1.2 Mg ha^-1. Crude protein ranged from 7.8 to 28.1%. Relative feed value ranged from 87 to 231. A detailed summary of statewide results will be presented.