The effect of companion crop management on the establishment of alfalfa was evaluated. The studied variables included species of cereals, row spacing and seeding rate of companion crop, stage of maturity of the companion crop at harvest, and an additional nitrogen fertilizer application. The cereals were harvested as forage. In the year after the seeding year, the first yield of alfalfa was determined. In seven trials, forage yields of a pure stand of alfalfa were 3350 kg/ha in the first cut of the seeding year. These yields averaged 60% of forage yields obtained from the combination of alfalfa and companion crop. However, cereals substantially reduced the total digestible nutrients, crude protein and calcium contents of the forage as compared to the pure alfalfa. The additional 38 kg/ha of nitrogen at tillering provided an extra yield of 600 kg/ha. Row spacing had little or no effect on forage yield. Even though wider spacings has considerably reduced seeding rates increased spacing from 18 to 54 cm did not affect barley yield while wheat was reduced by 400 kg/ha and oat increased by 300 kg/ha. Also, the average number of stems per meter of row increased by 89% with an average weight gain of 23% for each stem at the 54-cm spacing. At the first cut in the year following establishment, yields of alfalfa established with a companion crop were equal to or lower than those in pure stand. Yield reductions varied from 0 to 13% with barley and wheat but approached 30% when oats were seeded in 18-cm rows. However, the yield reduction was only 14% in the 54-cm row spacing of oats.Key words: Medicago sativa L., nitrogen fertilization, companion crop
