Sustainable Turkey Litter Amendments for Mixed Swards Grazed by Sheep in Appalachia Nitrate Leaching

Increased poultry production in the Appalachian Region provides a readily available nutrient source and a means to improve soil quality. As with any applied source of nutrients, surface and ground water quality can be compromised if nutrient inputs exceed plant nutrient requirements. Understanding nutrient dynamics in hill-land pasture enables us to develop management practices that minimize detrimental effects on water quality, and stabilize and improve the productive capacity of highly eroded soil. The objective of this research was to assess nitrate leaching under mixed swards of orchardgrass (Dactylis glomerata), white clover (Trifolium repens), and chicory (Cichorum intybus) receiving various loadings of composted turkey litter and grazed by sheep (Ovis aries). Treatments were applied in the early spring of 1997, 1999, and 2001 and consisted of P and K only; N, P and K; 3 Mg ha-1 composted turkey litter; and 6 Mg ha-1 composted turkey litter. Indications were that any of the treatments supplied adequate herbage to sustain rotational stocking of growing lambs at 50 lambs per hectare, but NO3-N leaching occurred at the litter application rate of 6 Mg ha-1. Nitrate leaching also occurred when no additionalN was applied as a result of an increased ratio of white clover in the sward. When chicory is included in the sward composition, rates of composted turkey litter application greater than 3 Mg ha-1 cannot be recommended from a NO3-N leaching perspective.