Characterization of nutrients in built-up broiler litter using trench and random walk sampling methods

Accurate sampling of broiler litter for nutrient analysis is critical for nutrient management and land application. Litter can be applied to agricultural land either fresh or after composting. If applied fresh, sampling should be done before house clean out so that the nutrient analysis results are readily available prior to land application. There are 2 methods that are suitable for obtaining representative litter samples in poultry houses, the trench and the point methods. This study was designed to investigate the effect of sampling methodology on the resultant nutrient content of broiler litter and how nutrient concentrations in broiler litter differ between brooding and nonbrooding areas in the production unit. The sampling methods gave similar results for litter pH, moisture content (MC), total Kjeldahl nitrogen (TKN), and total phosphorus (TP), thus indicating that the random walk method can be used to easily collect representative samples instead of the more time- and labor-intensive trench method for nutrient management purposes. The total ammoniacal nitrogen (TAN) content was significantly higher for the trench method, however, TAN accounted for less than 15% of the litter TKN. Litter MC, TAN, and TP varied significantly in each of the nonbrooding areas and the brooding area. Moisture content was 28.5, 32.0, and 28.0% for the brooding, north, and south nonbrooding areas, respectively. Litter TKN levels were 37.4, 24.9, and 20.5 g/kg for the brooding, north, and south nonbrooding areas, respectively. The TAN concentrations were higher at the north nonbrooding areas. The TP concentrations were 10.4, 8.8, and 8.5 g/kg for north nonbrooding area, brooding area, and south nonbrooding area, respectively. Our results indicate the need for sampling litter in both brooding and nonbrooding areas in broiler houses for the determination of average litter nutrient and MC.