The impact of underseeding forage mixtures on barley grain production in northern North America

Abstract

Livestock farmers in Newfoundland grow most of their required forage, yet must import most feed grain. Growing barley (Hordeum vulgare L.) in the year of forage establishment may allow for the incorporation of grain production into local cropping schemes. We examined the effect of barley grain production over an establishing timothy (Phleum pratense L.)-clover (Trifolium pratense L.; T. hybridum L.) forage sward in a 4-yr study near St. John’s. The experiment compared two barley varieties (differing in plant height), three barley seeding rates and the effect of a forage under-story on grain production in the establishment year, and forage production in the subsequent year. Increasing barley seeding rate from 125 to 375 plants m-2 resulted in a linear increase in spikes m-2, which led to a linear increase in barley yield. Pure-stand grain yields did not differ from those undersown to forage mixtures. The production of barley grain in the establishment year did not alter forage yield in the subsequent year (at any barley seeding rate or cultivar archetype). The barley crop did alter forage species composition in that higher seeding rates resulted in 15% less timothy in the forage production year. Barley undersown at a rate of 375 seeds m-2 with a timothy-clover mixture can be produced successfully in Newfoundland. Key words: Hordeum vulgare L., alsike clover, red clover, underseeding, companion planting, Newfoundland