Yield and quality of forage from intercrops of barley and annual ryegrass

Abstract
Three spring barley (Hordeum vulgare L.) and four annual ryegrass (Lolium multiflorum Lam.) types were intercropped to evaluate the potential yield and quality of forage which can be produced under irrigation in southern interior B.C. All treatments were intercrops; when barley cultivar effects are described they are averaged over the ryegrasses and vice versa. Barley cultivars differed in grain maturity. Ryegrass cultivars included diploid and tertraploid Italian and Westerwolds types. Intercrops including late grain maturing barley cultivars (Samson and Virden) increased the yield of the first silage cut (both by 25% over 2 yr) compared to Diamond, a medium-maturing cultivar adapted to the area. Intercrops containing the semi-dwarf barley, Samson, produced more digestible forage including higher in vitro digestible dry matter (IVDDM) and lower ADF and lignin. Annual ryegrass yield in the first cut intercropped with Samson was almost twice that with either Diamond or Virden, showing that Samson barley is less competitive. Second-cut yield (ryegrass regrowth) was greater for tetraploid than diploid annual ryegrasses. Yields of fall pasture (cuts 3 and 4) were similar among ryegrass cultivars. Cuts 2 and 3 (ryegrass only) of Italian ryegrasses had superior quality (higher IVDDM and protein; and lower ADF, lignin, and NDF) to Westerwolds ryegrassses, but all cultivars had similar quality in the late fall (Cut 4). It was concluded that a range of barley and annual ryegrass cultivars can be successfully intercropped to produce forage in south central B.C.Key words: Intercropping, barley annual ryegrass, forage yield and quality