17.3 11.3 11.8 30.0 34.6 38.9 Nitrogen Rate Stockpiled fescue yield and quality are also influenced by the rate of nitrogen applied. If fescue pastures are high in summer annual grasses, such as crabgrass or foxtail, nitrogen efficiency for tall fescue growth will be low. The summer annual grasses that are growing vigorously in August will take up most of the available nitrogen, leaving little for the fescue. Therefore, nitrogen fertilization for stockpiling should be limited to pastures with a vigorous fescue sod that are relatively free of summer annual grassy weeds. When applying nitrogen in the summer, keep in mind that some forms are subject to surface volatilization resulting in loss of available nitrogen to the plants.
Ammonium nitrate is an excellent form to use because surface volatilization losses are minimized.
Urea is a cheaper source of nitrogen, but the nitrogen can be completely lost under conditions favoring volatilization. It is best to apply urea fertilizers just before a minimum of 0.5 inch rainfall so the nitrogen is washed into the soil. Do not use urea if the pasture has been surfacelimed within the past three months. For more information on nitrogen forms and volatilization losses refer to Agronomy Facts AGF-205, available through county Extension offices. The need for late-summer nitrogen application on fescueclover pastures should be evaluated in terms of the forage needs of each specific operation.