Poultry Litter as a Sustainable Fertilizer for Stockpiled Tall Fescue during Winter Grazing in Middle Tennessee

Poultry litter has been used in crop production for many years and is particularly well suited for use as a plant nutrient source because of its high nutrient content compared with other manures. The objective of this research was to compare forage yield, forage nutritive value, beef cattle performance, and economics of stockpiled tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] fertilized with commercial fertilizer or poultry litter. The research was conducted from October 2013 to April 2015 at the Middle Tennessee AgResearch and Education Center of the University of Tennessee, in Spring Hill. The experimental design was completely randomized with two treatments- ammonium nitrate used as commercial fertilizer or poultry litter-replicated three times. For the plant morphological components and forage nutritive value, there were no differences between N sources. However there was a year × N source interaction (P = 0.04) for crude protein (CP) concentration with CP values averaging 9.8% in 2014 and 10.8% in 2015. There were no differences between N sources for average daily gain (ADG), which was 1.19 lb/day in 2014 and 0.95 lb/day in 2015, or for stocking rate, which was 0.65 animal units (AU) per acre in 2014 and 0.49 AU/acre in 2015. In assessing N requirements of stockpiled tall fescue, producers should consider the cost of buying, transporting, and applying poultry litter compared with the cost of commercial fertilizer sources before making a decision to fertilize a particular pasture.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Dep. of Plant Sciences Univ. of TennesseeDepartamento de Ciências Exatas Faculdade de Ciências Agrárias e Veterinárias UNESP-Univ. Estadual PaulistaDep. of Agricultural and Resource Economics Univ. of TennesseeDep. of Animal Science Univ. of TennesseeDepartamento de Ciências Exatas Faculdade de Ciências Agrárias e Veterinárias UNESP-Univ. Estadual PaulistaFAPESP: 2013/25202-

Nitrogen Rate and Initiation Date Effects on Stockpiled Tall Fescue During Fall Grazing in Tennessee

In Tennessee, N is one of the most common limiting nutrients for tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] production. Rising prices for N fertilizer have pressured cow-calf producers in Tennessee to reevaluate N management alternatives. The objectives of this study were to determine the effect of initiation date and N fertilization on stockpiled tall fescue yield, nutritive value, animal performance during fall grazing, and overall profitability of the production system. The research was conducted in tall fescue pastures at the Plateau AgResearch and Education Center in Crossville, TN from August 2013 to December 2014. A completely randomized design with three replications was applied to existing tall fescue pastures. Stockpile initiation dates were 1 August and 1 September, and N fertilization rates were 0 and 60 lb/acre N. With the exception of crude protein (CP) and in vitro dry matter digestibility (IVDMD), all other plant-related variables analyzed in this study showed a significant difference among monthly grazing periods. Nitrogen fertilization rate did not affect forage mass or nutritive value in both years. There were no significant interactions between initiation date and N fertilization rate for all animal performance measures. Data from this study suggests that with low beef prices ($0.75/lb), profits are maximized by initiating stockpiling in August with no N application.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Tennessee, Dept Plant Sci, Knoxville, TN 37996 USAUniv Estadual Paulista, Fac Ciencias Agr & Vet, Dept Ciencias Exatas, BR-14884900 Jaboticabal, SP, BrazilUniv Tennessee, Dept Agr & Resource Econ, Knoxville, TN 37996 USAUniv Estadual Paulista, Fac Ciencias Agr & Vet, Dept Ciencias Exatas, BR-14884900 Jaboticabal, SP, BrazilFAPESP: 2013/25202-