Management of Bedded-Pack Manure From Swine Hoop Structures: 1998 Results
Hoop structures are an increasingly popular alternative to conventional confinement facilities for swine production. Animals bed and dung on a bedded manure pack, which generates heat and contributes to animal comfort during winter months. As it comes directly out of the hoop structure, the high degree of variability in the bedded pack makes it difficult to predict manure nutrient contributions to crop fertilization needs. Although manure from the dunging area has clear fertilizer value, the high-carbon (C) lownitrogen (N) status of the drier bedding may lead to nitrogen immobilization and crop stress if applied during or immediately prior to the growing season. This study examined the distribution of moisture, N, and temperature of the bedded pack inside a hoop, and evaluated the effect of 4 composting strategies on manure nutrient levels and uniformity, mass, volume, and moisture content. A simple loader built pile with no turning appeared to most effectively reduce nitrogen losses, but building piles with a manure spreader or frequent turning provided benefits in volume, mass, and moisture reduction. Composting did not consistently improve the nutrient variability of the manure, and additional studies are planned to address this concern.