Time of Nitrogen Supply in Yield and Industrial Quality of Oat Grains by Agricultural Condition

The timing of nitrogen application in oats improves the efficiency of use of the nutrient, expressing the yield and industrial quality of grains. The objective of the study is to indicate the appropriate timing of nitrogen supply on the yield and industrial quality of oat grains, considering the use of low and high dose of nitrogen at sowing and favorable and unfavorable years for cereal growing in soybean/oat system. The experiment was conducted in the years 2016, 2017 and 2018, in Augusto Pestana, RS, Brazil. The experimental design was a randomized block with four replications in a 2 x 4 factorial, for two doses of nitrogen at sowing (5 and 25 kg ha-1), changing the top dressing dose by the total supplied of 70 kg ha-1, in the expectation grain yield of 4000 kg ha-1, with time of supply at 0, 10, 30 and 60 days after emergence. In an unfavorable and intermediate year for the growing of oats, it is necessary to increase the dose of the nutrient at sowing in order to favor greater amplitude of the time of application in top dressing. In a favorable year, whether low or high, this range of application is guaranteed. Regardless of the reduced and high dose of nitrogen at sowing, the greatest expression of grain and industry yield occurs with the nutrient applied at 30 and 35 days after emergence in an unfavorable year, 35 days in an intermediate year and 40 to 45 days in a favorable year, respectively.