Effects of Fertilizer Application on Nitrogen Utilization Efficiency and Nitrate Content in Hybrid Pennisetum

Effects of fertilizer application on nitrogen utilization efficiency and nitrate content in hybrid Pennisetum was studied in Nanjing,Jiangsu province.The results were showed as follows:dry matter yield and total nitrogen accumulation in hybrid Pennisetum reached the highest and dry matter production efficiency by nitrogen was relatively low as fertilization combination of 67 500 kg/hm~2 manure plus 270.0 kg/hm~2 chemical nitrogen was applied;at the same time,nitrate content in forage was higher than 0.25% in second,third and fourth defoliation,which could cause potential nitrate toxic danger when the forage was fed lonely.Nitrogen dry matter production efficiency and dry matter yield were higher than those in other fertilization combinations as 45 000 kg/hm~2 manure plus 270.0 kg/hm~2 chemical N or 67 500 kg/hm~2 manure plus 67.5 kg/hm~2 chemical N was applied.In the above two treatment,nitrate contents in forage were lower than 0.25% in the second,third and fourth defoliation which would cause no toxic danger for animal 45 000 kg/hm~2 manure plus 270.0(kg/hm~2)chemical N and 67 500 kg/hm~2 manure plus 67.5(kg/hm~2) chemical N were regarded as two optimum fertilizer de signs for hybrid Pennisetum if nitrogen uptake and utilization efficiency and nitrate content were considered synthetically.