Effects of Broiler Litter and Nitrogen Fertilization on Uptake of Major Nutrients by Coastal Bermudagrass

Land application of poultry litter provides essential nutrients for hybrid bermudagrass [ Cynodon dactylon (L.) Pers.] production, but ammonia (NH 3 ) volatilization and N mineralization influence the amount of litter N available for plant uptake. Our objective was to determine the combination of broiler litter and fertilizer N, which maximizes the yields of forage and N, P, and K by ‘Coastal’ bermudagrass. Studies were conducted for 3 yr (1999–2001) in pastures at Newton and Mize, MS that differed widely in soil test P (STP) due to history of litter application (0 vs. 30+ yr, respectively.). Litter rates of 0, 4.5, 8.9, 13.4, and 17.9 Mg ha −1 were obtained by up to four monthly (April–July) applications of 4.5 Mg ha −1 and were supplemented with ammonium nitrate (NH 4 –NO 3 ) to provide the same total N in each treatment. At Newton, combining litter with fertilizer N increased forage yield by 10% in 1999, 25% in 2000, and 34% in 2001, as compared to fertilizer N. At Mize, K uptake increased as litter rate increased in 2001 only. These responses to litter were related to increased soil P and K at Newton, and increased soil N, P, and Ca at Mize. Averaged across years, maximum P uptake of about 40 kg ha −1 was obtained by applying 8.9 Mg litter + 134 kg N ha −1 at Newton and 4.5 Mg litter + 202 kg N ha −1 at Mize. Safe and effective management of major plant nutrients in broiler litter may require the use of commercial N fertilizer.