Using poultry litter in black walnut nutrient management

Poultry litter was evaluated as a fertilizer in a young (three-year-old) and an old (35-year-old) black walnut (Juglans nigra L.) plantation in southwest Missouri. The older planting had a fescue (Festuca arundinaceae Schreb.) ground cover that is grazed by cattle. In the young plantation, weeds were mowed and sprayed with herbicides once annually in the spring. Litter was applied at rates of 6.72 Mg ha(-1) and 13.44 Mg ha(-1) for one year in the spring in the young plantation and at 8.96 Mg ha(-1) for two years in the spring and once in late summer in the older plantation. Height growth and leaf nitrogen (N) concentrations were improved during the summer following litter applications in the young plantation, but neither diameter growth nor nut production increased in the older plantation. Second-year height growth treatment differences for the young plantation were not significant. The number of nuts increased in the second year, but differences between treatments were not significant.