Has the contribution of animal manure to the phosphorus loads delivered to the Gulf been previously documented?
|Back to Top| The study reports that, on average, 37% of the phosphorus load that is delivered to the Gulf originates from non-recoverable animal manure in the Basin. The estimate is about twice as large as previously estimated for the Mississippi River Basin in the 1999 Gulf of Mexico Hypoxia Assessment (Goolsby et al., 1999). This USGS study defines non-recoverable animal manure as the manure that is not recoverable for use as fertilizer on cropland. This includes manure from unconfined animals and manure lost during the collection, storage, and treatment of wastes from confined animals, including concentrated animal feeding operations. Non-recoverable manure is primarily associated with pasture and rangelands.
