Determination of optimum rate and application time of nitrogen for yield and quality of malt barley (Hordeum vulgare L.) in Dabat district, Western Amhara, Ethiopia

Abstract

Malt barley is an important crop for Ethiopia’s agro-industrial development and smallholder livelihoods. However, its productivity and grain quality remain low due to suboptimal agronomic practices. To address this limitation, a field experiment was conducted to investigate the effects of nitrogen (N) application rates and split-application strategies on agronomic traits, yield, and grain quality. The experiment was arranged in a randomized complete block design with three replications, and data were analyzed using R statistical software (version 4.3.2). The treatments comprised 12 combinations: four N rates (46, 92,138, and 184 kg N ha⁻¹) and three application schedules (½ at planting + ½ at tillering; ¼ at planting + ¼ at tillering + ½ at booting; and ⅓ at planting + ⅓ at tillering + ⅓ at booting). The results showed that both N rate and application timing significantly affected spike length, kernels per spike, thousand-kernel weight, grain yield, and protein content. The highest grain yield (2.65 t ha⁻¹), thousand-kernel weight (43.04 g), spike length (7.97 cm), kernels per spike (42), and protein content (13.6%) were achieved at 184 kg N ha⁻¹. However, partial budget analysis indicated that the treatment with 92 kg N ha⁻¹ provided the highest net benefit (1324.84 USD ha⁻¹) and a marginal rate of return of 292.64%. Therefore, applying 92 kg N ha⁻¹ split as 1/2 at planting, and ½ at tillering stage is the most effective and economically feasible practice for malt barley production in the study area and similar agro-ecological zones.