The effects of grazing winter small grains

Two varieties representing erect and prostrate types of each of the winter small grains, oats, barley, wheat, and rye, were grazed with sheep at Knoxville, Tenn. during the years 1943-44, 1944-45, and 1945-46 to determine the effects of this forage removal on subsequent grain yields, plant height, tillering, and maturity. The rye, barley, and oats produced approximately equal amounts of forage in the fall, whereas the wheat produced the least fall forage. In the spring the rye furnished the largest amount of forage, the barley and wheat next largest, and the oats the smallest amount. In total forage production, rye out-yielded the other small grains with only minor differences in total forage yields occurring between barley, wheat, and oats. Differences in forage production between erect and prostrate varieties of the same small grains were minor and did not appear to be related to growth habit. Grazing with sheep as practiced in these experiments was detrimental to grain production of all the four small grains. On a percentage basis this reduction in grain yield ranged from a low of 23.2% to a high of 46.7%, depending upon the variety and kind of small grain. Except for rye, growth habit was directly related to grain yield reductions caused by grazing. The prostrate growing types suffered less reduction than the erect types. Grazing also reduced plant height and tillering and postponed ripening from 4 to 8 days. As regards these characteristics, growth habit was associated only with plant height reduction; as in the case of grain yield, the height of prostrate varieties was reduced less by grazing than that of erect varieties. As indicated by chemical analyses of the forage obtained only in 1945-46, small grain forage is high in protein, calcium, and phosphorus. Fall forage proved to be superior to spring forage in the components mentioned. Observations on palatability indicated that oats were preferred by sheep to the other small grains. The palatability relationships of the other small grains and of the varieties themselves were not clear, since the sheep were inconsistent in their preferences. There did not appear to be any direct association between palatability of the various varieties and their growth habits.