Nitrogen Fertilizer and Seeding Rate Influence on Grain and Forage Yield of Dual‐Purpose Barley

Abstract

Clipping fall-sown cereals provides a good source of high-quality forage during late winter. Farmers usually use more inputs, including fertilizers and seed, in dual-purpose systems compared with grain-only systems. A 2-yr fi eld study was conducted in Karaj, Iran, to evaluate the eff ects of nitrogen (N) rates (0, 50, 100, 150 kg N ha -1 ) and seeding rates (400, 600, 800 seed m -2 ) on forage and grain yields of two barley (Hordeum vulgare L.) cultivars (Fasih and CB 744) in grain-only and dual-purpose systems. Fasih and CB 744 grain yields in the grain-only system were 2996 and 3250 kg ha -1 , respectively (averaged over experimental treatments). Forage removal in the dual-purpose system resulted in 25% grain yield penalty. Despite the lower grain yield, the economic return of the dual-purpose system was considerably greater due to the high price of forage during late winter in the region. Grain yield response to N was linear in the grain-only system, but the trend was not signifi cant in the dual-purpose system. In both production systems, grain yield response to seeding rate was quadratic, and the highest yields of both cultivars (2534 and 3192 kg ha -1 for Fasih and CB 744, respectively) were obtained from 600 seed m -2 . In both production systems, 600 seed m -2 and 100 kg N ha -1 were optimum for grain and forage production. Our results showed considerably higher revenue in the dual-purpose system compared with the grain-only system in this region. Moreover, no additional inputs of N and seed are required for dual-purpose barley than those usually used in a grain-only system.

Dual Purpose Barley Production in the Mediterranean Climate: Effect of Seeding Rate and Age at Forage Cutting

“…In many agricultural systems around the world, feed shortage during late winter and spring periods, limits the integration of livestock production (Hajighasemi et al 2016). The adoption of dual purpose winter cereal crops, that are cut or grazed during tillering and then left to regrow for grain production, is widely practiced in many Mediterranean countries to narrow the gap between forage supply and demand in the shortage periods (Sadreddine 2016).…”

“…Some crop management practices and their influence on the success of the dual purpose system has been heavily investigated. For example, it is well known that, to support the dual purpose system, sowing should be done earlier than in case of grainonly system (Hajighasemi et al 2016). Nevertheless, limited knowledge is available about the optimum seeding rate and cutting management that should be practiced to maximize forage production with minimal reduction of grain yield, and thus achieve success from the dual purpose system.…”

Producción de cebada (Hordeum vulgare L.) con urea normal y polimerizada en Pintag, Quito, Ecuador.

“…Para la urea normal se obtuvo una tendencia en la respuesta de tipo lineal creciente (p=0,15; r 2 = 0,44), misma que indicó que las dosis de FN utilizadas en este sitio fueron bajas con respecto a los requerimientos del cultivo, y no permitieron alcanzar la DON o calcular la PDON, resultado que refleja la alta pérdida de N, probablemente por la excesiva precipitación. Una respuesta de tipo lineal en un estudio realizado en Karaj, Irán, la obtuvieron Hajighasemi et al (2016). En cambio, la urea polimerizada mostró una tendencia en la respuesta de tipo cuadrática platea con una DON de 25 kg N/ha y una PDON de 2,35 t/ha.…”

“…Los resultados para la urea polimerizada en este sitio fueron inconsistentes con las recomendaciones de fertilización que maneja Cervecería Nacional. En algunos casos, la variabilidad climática y de manejo del cultivo tienen alta influencia en la producción del cultivo y esto puede resultar en respuestas no significativas a la FN (Hajighasemi et al, 2016). La alta variabilidad en la respuesta a la FN en el sitio 2 fue un reflejo de la excesiva precipitación en este sitio durante la evaluación.…”

“…Moreno et al (2003) indicaron que una producción óptima de cebada requiere 120 kg N/ha como fertilizante, y que aplicaciones superiores a 150 kg N/ha resultan en excesivo costo de producción y disminución en la productividad. En cambio, si se desea maximizar la rentabilidad del cultivo, Jankovic et al (2011) sugirieron fertilizaciones entre 50 y 110 kg N/ha, y Hajighasemi et al (2016) indicaron que solo se debe aplicar 100 kg N/ha.…”