Forage Quality and Performance of Tall Fescue Hay Amended with Broiler Litter and Commercial Fertilizer

Broiler chickens are a leading agricultural commodity in Tennessee. Many broiler operations are located in eastern and middle Tennessee where a common land use is tall fescue (Festuca arundinacea Schreb.) hay and pasture, for cow-calf and dairy operations. Litter from broiler operations is land applied on fescue at rates that often exceed the recommended phosphorus (P) and potassium (K) rates. Surveys of forage quality conducted by the University of Tennessee Extension in 2001 found that many forages across the state had higher than recommended K and sulfur levels and were deficient in copper (Cu) and other nutrients. In spring 2004 a two-year study initiated at the Research and Education Center at Greeneville, TN evaluated the performance and forage quality of tall fescue hay amended annually with 3 rates of broiler litter (2.3, 6.8, and 11.3 Mg/ha) and 2 commercial fertilizer rates (a recommended rate, 114-30-28 kg/ha of NPK; and a commonly used rate 65-29-54 kg/ha of NPK). The study was conducted on a Dewey silt clay loam (fine, kaolinitic, thermic, Typic Paleudult), severely eroded soil (12 to 25 percent slope). Mehlich I soil analysis indicated increased phosphorus (P) and increased zinc (Zn) levels after application and harvest. All plots were harvested in May 2004, September 2004, and May 2005. Forage analysis was conducted to determine the nutrient content in the fescue. Dry matter yields of higher quality forage were obtained using high litter rates (11.3 Mg/ha) and the recommended fertilizer rate. In 2004 and 2005, Cu, Na, and Zn levels were below and (S) sulfur levels above National Resource Council (NRC) recommendations for beef cattle, while Ca and Mg were above recommendations. Using high litter applications (11.3 Mg/ha) resulted in K levels at or above maximum tolerable concentration (30 g/kg) critical for beef cattle in May 2004 and 2005