Introduction
Mississippi has about 1,450 poultry farms producing 762 million broilers per year that are processed and shipped locally, across the country, and around the world. Poultry has been leading the state as the largest agricultural commodity for 20 straight years. In 2013 alone, farmers were paid $2.7 billion, and 28,000 employees were paid another $2.1 billion in wages and salaries (Mississippi Poultry Association, 2014). Management of poultry litter generated on the state’s poultry farms is an increasingly important environmental issue in Mississippi. Poultry litter is a mixture of manure, feathers, and bedding material that is a valuable source of plant nutrients and organic matter. The fertilizer value and organic matter make poultry litter of great interest to many livestock and row-crop farmers across Mississippi. Even though new and innovative methods of using poultry litter continue to evolve and develop, land application currently remains the most sustainable option. However, land application of litter is being closely scrutinized regarding short- and long-term environmental impacts, especially as it relates to phosphorus (P) runoff and its potential role in accelerating eutrophication (Sharpley et al., 2009). Eutrophication is a process by which runoff from a source such as a fertilized field may cause a lake, pond, or other body of water to become overly rich in organic nutrients, so that algae growth increases rapidly and may deplete the oxygen supply. Additionally, without correctly sampling and analyzing litter before it is land applied, there is no way to determine its true fertilizer value. If land application of litter is to accurately meet the needs of the current crop, an up-to-date soil test analysis is also needed. In fact, to remain in compliance with Mississippi’s Dry Litter Poultry General Permit, poultry litter must be analyzed a minimum of once annually for nitrogen (N) and P. Furthermore, soil must also be analyzed at a minimum of once every 5 years for P content. Currently, the Mississippi State Chemical Laboratory located on the Mississippi State University campus provides a poultry litter analysis for $35 per sample. This analysis determines potash (K2O equivalent), total N, moisture content, P as P2O5 (phosphoric acid), and pH. Nutrient (N-P-K) content is reported on a dry basis, on an as-received basis, and on a pounds-per-ton basis. The Soil Testing Lab (also located on the MSU campus) can provide routine soil analysis for $8 per sample. Extension agents in your county can provide guidance and instruction in proper soil and litter sampling procedures. In addition, Extension poultry and soil specialists located on the MSU campus can provide further assistance, if needed. Contact your local Extension office for the most up-to-date information on sample collection and analysis. While the fertilizer value of litter is well-recognized, the nutrient concentration can be extremely variable (VanDevender et al., 2000). To date, Chamblee and Todd (2002) reported the only data that currently exists describing the nutrient value of broiler litter in Mississippi. Changes in production practices during the last 12 to 15 years, such as increased emphasis on paw quality, house clean-out schedules, windrowing of litter between flocks, heavier bird market weights, phytase use in feed to aid in P availability, closely matching P levels in feed with bird requirements (precision nutrition), and litter amendments used by many growers to help control ammonia early in the flock, may have changed the litter’s nutrient value. Therefore, the objective of this study was to determine the current nutrient value of Mississippi broiler litter.
