Effect of Mixed Cover Crop Functional Groups on Barley Yield and Quality.

Dryland crop production in Montana is dominated by a cereal grain -- fallow crop sequence due in large part to limited annual precipitation that ranges from 250 to 400 mm. In Montana the majority of these 1.3 million hectares are established under no-tillage conditions. Since tillage is minimal, increased cropping diversity could be the next step to improving soil quality. Diversity can be increased by the inclusion of cover crops during the fallow period which would not decrease the total acreage planted to cereal grains. Multi-species cover crops have been successfully incorporated in areas of higher annual precipitation. But for Montana, questions remain on what combination of cover crop species provides the best complement to cereal grain production. A mixed species cover crop study was begun in 2014 utilizing three functional cover crop groups including legumes: soybean and spring pea; taproot crops: safflower and turnip; and grass crops: barley and Sudan grass. Monocrop covers of each species, all functional groups, and combinations of two out of three functional groups, plus a fallow check resulted in 11 treatments. In 2015, malt barley was planted across all previous treatments using nitrogen rates of 0, 28, 56, and 84 kg ha^-1 in a strip-strip plot design. Results of the first two years of cover crop production and the impact on malt barley production are presented.