Intensive spring nitrogen management of winter barley: silage and grain yield and composition

The impact of rate and timing of spring nitrogen application on yield and composition of barley forage and grain and the fermentation and utilization of barley silage was investigated in a 3-yr study. The use of a growth regulator, ethephon, was also investigated. Nitrogen application at a rate of 135 kg/ha increased forage yields in 1984 and tended to increase yields in 1985 and 1986 though dry conditions existed. Crude protein yield was increased with application of 135 kg N/ha all three years. Major impact of N. fertilization appeared to be associated with an application at Feekes stage 5. Nitrogen treatments had little impact on nitrate, NDF or ADF concentration but higher rates generally lowered forage dry matter. Use of N resulted in increased dry matter intake and increased dry matter, crude protein, NDF, and ADF digestibility of silage when fed to lambs. In 2 of 3 yr grain yield appeared to be lowered as forage yield increased due to N treatment. Grain crude protein and crude protein yields were increased with the use of N. Increases in grain crude protein content were associated with applications of N at Feekes stage 5. Generally, test weight and 1000 kernel weight decreased and the number of tillers increased at rates of N application were increased. Use of Ethephon tended to increase yields in 1984 and increased yields in 1985.