Effect of nitrogen and zinc on growth characters, herbage yield, nutrient uptake and quality of fodder sorghum (Sorghum bicolor)

A field trial was conducted at the Livestock Research Centre of the Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, during the rainy (kharif) season of 2001 and 2002, to study the effect of nitrogen and zinc on growth, herbage yield, nutrient uptake and quality of herbage in fodder sorghum [Sorghum bicolor (L) Moench]. Increase in nitrogen application from 0 to 120 kg/ha increased the green herbage yield (434.9 q/ha) and dry fodder (157.9 q/ha) of sorghum, being 35.8 and 43.1% higher over the control respectively. The crop responded up to 5 kg zinc/ha which increased the yield of green herbage 8.6% and dry fodder 11.5% over no zinc. Crude protein and digestible dry-matter yield were significantly higher at 120 kg N/ha than other N levels. Zinc also significantly responded up to 5 kg/ha in respect of quality. Almost similar trend was also observed in N and Zn uptake. The optimum dose for N and Zn were calculated to be 108.3 kg and 1.36 kg/ha and maximum yields were with the application of 126.67 and 5.53 kg/ha respectively.