Abstract:<br><br><p> Winter wheat (Triticum aestivum, L.) (WW) is the primary dryland crop in the semi-arid US Great Plains. Local producers in extremely low precipitation areas are interested in incorporating cover crops (CC) into a WW-fallow rotation. Information on suitable CC mixes and their impact on soil and competition with weeds is limited. A producer designed and planted two CC mixes: (1) legume dominated three species mix (69-17-14) (3 species legume-dominated): forage pea (Pisum sativum, L.), red clover (Trifolium pratense, L.), and daikon radish (Raphanus sativus, L.) and (2) grass dominated four species mix (55-35-7-3) (4 species grass-dominated): oat (Avena sativa, L.), forage pea, daikon radish, and purple top turnip (Brassica rapa, L.). The CC performance was compared to a weedy fallow (WF) (tilled once and allowed to fallow without weed control) and a cultivated fallow (CF) (tilled five times for weed control). Soil and vegetation sampling took place at 11 weeks and 26 weeks after CC planting. Soil was analyzed for water content and inorganic nitrogen (IN) concentrations and CC and weedy species vegetation biomass was analyzed. Results suggest that soil moisture at the time of WW planting was not negatively affected by CC. The 4 species grass-dominated mix resulted in 97% higher soil IN than weedy fallow and outperformed the 3 species legume-dominated mix in competing with weedy species (73% reduction in weedy biomass). In conclusion, for areas of extremely low precipitation, fallow could be replaced by planting the 4 species grass-dominated CC mix tested in this experiment. </p>