THE EFFECT OF SPRING AND FALL APPLICATION OF N ON YIELD AND QUALITY OF BARLEY (Hordeum vulgare L.) AND RAPESEED (Brassica campestris L.)

Application of N fertilizer in the fall as opposed to spring has been a controversial recommendation for cereal crops grown in Western Canada. Also, oilseed crops such as rapeseed may not respond to N in the same way as cereals. To investigate spring and fall application of N on barley and rapeseed, factorial split plot experiments were designed with three N treatments of 45, 90 and 134 kg N ha−1 and four P treatments of 0, 9.4, 18.8 and 28.2 kg P ha−1, as main plots. A control without fertilizer was included and the subplots were spring and fall times of broadcast application of ammonium nitrate fertilizer. Barley (Hordeum vulgare L.), cultivar Conquest and rapeseed (Brassica campestris L.) cultivar Arlo were seeded as the test crops over a 5-yr period and a 6-yr period, respectively, at separate sites on Melfort silty clay soil to determine the differences in yield and quality of grain between spring and fall applied N. In some years yield response to N fertilizer was greater when applied in the spring ...