Grain yield and malting quality of barley in relation to nitrogen application at mid- and high altitude in Northwest Ethiopia

Abstract

In the main cropping seasons of 2006-2007, a two-year field experiment on the response of malting barley varieties to nitrogen (N) application was conducted on nitosols of the Laie-Gaint, Gozamen and Yilmana-Denssa areas of northwestern Ethiopia. The aim was to determine the optimum N application rate for malting barley production. The experiment was a complete factorial arrangement in RCB with three replications. It consisted of 12 factorial combinations of four N rates (46, 69, 92, 115 kg N ha-1), and three recently released malting barley varieties (HB-52, HB-1533 and Miscale-21). A blanket application of 46 kg ha-1 P (as P2O5) was applied across all treatments at the time of sowing. Grain yield and its protein content in all locations increased almost linearly as the N rate increased. Based on the findings of the experiment, it is recommended that fertiliser rates of 115/46 kg N/P2O5 ha-1 for HB-52, and 92/46 kg N/P2O5 ha-1 for Miscale-21, are economically optimum rates, with an acceptable grain quality standard in the Laie-Gaint, Yilmana-Denssa and Gozamen areas. For variety HB-1533, fertiliser rates of 92 kg N ha-1 and 115 kg N ha-1 are recommended, with acceptable grain quality in the Laie-Gaint and Gozamen areas, respectively. It is not recommended to grow the variety HB-1533 in the Yilmana- Denssa area, owing to its high protein content. Selection of appropriate varieties for different localities was also found to be crucial for maintaining the grain quality of malting barley at its standard level.