OAT, OAT-PEA, BARLEY, AND BARLEY-PEA FOR FORAGE YIELD, FORAGE QUALITY, AND ALFALFA ESTABLISHMENT

There is no known published work on the use of pea (Pisum sativum L.) in mixture with oat (Avena sativa L.) or barley (Hordeum vulgare L.) as a companion crop for the establishment of alfalfa. The objective of this field study was to determine the effect of field pea [Pi. sativum L. var. arvense (L.) Poiret] on alfalfa (Medicago sativa L.) establishment when seeded in mixtures with oat or barley. In addition, forage yield and quality of oat and barley and their mixtures with pea were assessed. Sixteen oat and nine barley genotypes were grown alone and in mixtures with 'Trapper' field pea to produce oat, oat-pea, barley, and barley-pea companion crops. The companion crops were underseeded with 'Blazer' alfalfa. No single oat or barley cultivar or experimental genotype, whether mixed with pea or not, was distinctly superior for forage yield, forage quality, and subsequent alfalfa yield in the year after alfalfa establishment. Pea did not significantly affect alfalfa yield in the establishment year nor in the year after establishment. The addition of pea to oat decreased neutral detergent fiber (NDF) by 7.1 percentage units and increased crude protein (CP) by 4.4 percentage units, while adding pea to barley decreased NDF by 6.2 percentage units and increased CP by 3.0 percentage units. The oat-pea forage mixture was significantly lower in NDF and significantly higher in CP than barley-pea forage mixture. Although barley-pea was highest in forage yield, we concluded that oat-pea was the best companion crop in this study because it had superior forage quality.