Case Study of Swine Finishing Manure Nutrient Characteristics for Land Application

In modern animal agriculture, implementation of practices improving the sustainability of livestock production has been a key goal. As a means of achieving this objective, farmers decreased the inputs for live production through nutrition and equipment modifications to decrease the feed and water wastage. These practices and changes have also impacted manure characteristics. Thus, the objectives of this work were to report the impact of changing to wet-dry feeders and manure storage types had on manure production and nutrient concentrations, and discuss these impacts on farm manure management planning. This study examined manure samples from 2001 to 2015 and manure applications from 2007 to 2015 from swine finishing facilities in Iowa that utilized deep pits, vats, and lagoons for manure storages. Over time the manure concentrations for nitrogen, phosphorus and potassium increased across all storage types. Pits had the highest concentrations of all nutrients. A significant increase in nutrient concentrations were seen when changing from dry feeders to wet-dry feeders in deep pit and lagoon storage systems for nitrogen, phosphorus and potassium. The changes in vats were not significant. Results and analysis of the manure production and manure applications showed that manure storage type leads to different estimates of nutrient production, presumably due to differences in nutrient conservation during storage. This study will examine the changes in application land coverage and application rates over time as it relates to the change in manure concentrations in nitrogen and phosphorus.