Effects of different nitrogen doses and harvesting times on the forage yield and quality of barley

This study was conducted at the Education, Research, and Application Farm of the Faculty of Agriculture, Isparta University of Applied Sciences, during the 2023-2024 growing season to determine the effects of different nitrogen doses and timing of application on the yield and quality of barley. The study applied 5 different nitrogen doses (0, 5, 10, 15, and 20 kg/da) at 3 different application times (heading stage, flowering stage, and milk stage). The experiment was set up in randomized blocks with split plots, with three replications according to the experimental design. Nitrogen rates were planned as main plots, while application times were planned as subplots. Plant height, green forage yield, hay yield, crude protein content, crude protein yield, NDF, ADF, total digestible nutrients (TDN), and relative feed value (RFV) were determined in the study. According to the research results, the plant height values in barley were 101.1-108.2 cm, green forage yield 3449.2-4123.6 kg da-1, hay yield 897.8-1302.2 kg da-1, crude protein content 5.83-8.99, crude protein yield 69.5-93.6 kg da-1, NDF 51.45-67.05%, ADF 38.65-51.63%, TDN 34.7-51.5% and RFV 67.5-106.3. As nitrogen doses increased, plant height, green forage yield, hay yield, crude protein content, crude protein yield, TDN and RFV increased, while ADF and NDF decreased. As the cutting times progressed, plant height, green forage yield, hay yield, crude protein yield, NDF and ADF ratios increased, while crude protein ratio, TDN and RFV decreased. When the results were evaluated as a whole, there wasn't a significant difference 15 and 20 kg of nitrogen applications per decare in terms of both yield and quality, while harvesting barley during the milk stage yielded the highest values in terms of yield and harvesting during the heading stage yielded the highest values in terms of quality. The trial concluded that the least loss in terms of yield and quality would be achieved with 15 kg of nitrogen per decare and harvesting during the flowering stage.