The Amount and Timing of Foliar Urea Application Effect on Maize and Forage Sorghum Proteins

This study was carried out for investigating the effect of amount and timing of foliar urea in increasing silage yield and protein content of fodder, in a maize field in Neyshabour, Khorasan Razavi Province during 2011 summer crop season. A split plot design with factorial arrangement and three replications were used. Treatments were timing of foliar urea application (a week before tasselling, mid anthesis and early milk stage), urea levels (zero (check), five and 7.5 g.lit-1) and two hybrids of corn (Sc 704) and forage sorghum (speed feed). The results indicated that the concentration of nitrogen had significant effect to increase forage protein and silage yield (correcting by 280 g.kg-1 of dry matter). The highest forage protein concentrations for both crops and silage yield were achieved with 7.5 g.lit-1 of urea application, but the silage yield of sorghum was more than that of corn. The results showed that urea spraying can effectively increase the fodder nitrogen and silage protein, respectively, with the least possible cost, and in this respect it has an important role in providing quality and environmental safe forage for producer and consumer, meanwhile the adverse effects of excessive use of nitrogen fertilizer are reduced.