Using Geostatistics to Determine Spatial Variability of Nutrients Within a Poultry House

Manure nutrient management calls for sampling poultry litter prior to field applications. The new Confined Animal Feeding Operations (CAFO) rules propose broiler (meat-type chicken) house sampling guidelines to derive nutrient load values, which may be used to determine fertilizer application rates or nutrient accountability upon litter transfer to a third party. Unanswered questions remain such as: how best to perform sampling of litter within the house, what is representative data, and how many samples are needed? Developing better sampling techniques may provide needed information for implementing sound manure management practices. Numerous studies, that primarily report averages and ranges of nutrient composition, have addressed nutrient availability in poultry litter (Smith et. al., 1994, Chamblee and Todd, 2002, Bitzer and Sims, 1988, Gordillo and Cabrera, 1997 and Westerman et al., 1988). One study was conducted to determine the difference between cake litter and non-caked litter. This study found that caked litter was higher in moisture and metals; howeve