THE EFFECT OF IMMATURITY AND HARVESTING METHOD ON THE YIELD AND PROPERTIES OF BARLEY STRAW

The effects of immaturity and harvesting method of barley grain on res idue yields and nutritive properties were investigated at Saskatoon, S askatchewan in 1983, 1984, and 1985. Three barley (Hordeum vulgare L.) cultivars (Betzes, Harrington, and Scout), were harvested at kernel m oisture contents (KMC) ranging from 56% to 12% using the traditional s wathing/air drying/threshing method and the direct combining/artificia l drying method. Residue nutritive changes that resulted from varying swathing height and from ammonia treatment were also studied. Harvesti ng immature barley increased the yield and nutritive value of the resi due but reduced grain yield and quality. In 1984, direct combining at 35% KMC yielded 40 % more residue but only 5% less grain than swathing . Nutritive value of the residue, determined by equivalent crude prote in (ECP) and in vitro organic matter digestibility (IVOMD), increased with higher KMC at harvest and was usually greater for direct combined than for swathed residue. Harvesting at a higher stubble height in 19 85 increased residue nutritive value. Ammonia treatment of residue fro m all KMC's and harvesting methods increased ECP by an average of 77% in 1983 and 144% in 1984, and the IVOMD by 19% both years. KMC at harv est had little effect on improved nutritive value resulting from ammon iation.