Nutrient seepage from operating Turkey buildings with a litter system

Core soil samples were collected from nine operating turkey buildings with different ages located in areas of different soil types in Minnesota. These samples were analyzed for pH, phosphorus, organic matter, ammonium nitrogen, and nitrate nitrogen to investigate the potential of groundwater pollution by turkey operations. According to the data, for clay loam soil, the chance of leaching of phosphorus to groundwater is slight if the water table is 153 cm below the ground surface. Saturation of ammonium nitrogen in the topsoil can be reached in 20 yr of continuous operation. Therefore, it may be suggested that the topsoil layer in turkey buildings be replaced every 20 yr for areas of high groundwater (within 91 cm or so), and every 40 yr for areas with low groundwater (greater than 153 cm in depth). Also for clay loam soil, the nitrate nitrogen may be able to move down in soil about 91 cm deep in ten years. For barns older than ten years, it is observed that the nitrate nitrogen concentrations are significantly higher inside than outside of barns throughout the entire sampling depth. As a preventive option for turkey producers for nitrate nitrogen in particular, replacing the topsoil layer every ten years may be helpful to obviate the potential pollution of groundwater resource by nitrate leaching. Similar measures may also be applied to loam soil. Due to limited data, the performance of silt and sandy loam soils in preventing nutrient leaching cannot be determined and should receive further research.