XVI International Botanical Congess

Our objectives were to evaluate the effect of different levels of nitrogen fertilization, on the nonprotein portion of the nitrogenous constitution of forage plants. At all four harvests, the concentration of (total Kjeldahl nitrogen) TKN in reed canarygrass increased almost linearly, as the level of nitrogen fertilizer was increased at rates up to the equivalent of 20 g N m-2. However, orchardgrass only showed a linear increase in the concentration of TKN at the 3 g N m-2 and 10 g N m-2 rates, with a leveling off occurring at rates of 15 g N m-2 and 20 g N m-2. The levels of nitrate in reed canarygrass were much lower than those measured in orchardgrass at the rates of 3 g N m-2, 10 g N m-2 and 15 g N m-2.