Repeated land application of dairy manure can increase soil phosphorus above crop requirements because of manure's low nitrogen (N) to phosphorus (P) ratio (N:P < 4:1). This soil P build-up can lead to off-site P transport and impairment of surface water quality. We evaluated a treatment process to extract P from manures, called Quick Wash, integrated with a double-stage solids separation system to recover coarse and fine manure solids. The Quick Wash process uses a combination of acid, base,

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... d organic polymers to extract and recover P from manures, improving the N:P ratio of recovered manure solids (RMS). Results showed that coarse RMS could have use as bedding materials for dairy cows, and the fine acidified RMS with N:P > 10:1 can be used as a low-P organic soil amendment. A soil incubation test showed that acidified RMS stimulated N mineralization and nitrification having higher nitrate levels than untreated dairy slurry when incorporated into soil. Our results suggest that the inclusion of Quick Wash in a dairy manure management system can improve manure's value, lowering costs of bedding material and manure hauling, and recover P for use as fertilizer while reducing the environmental impact of land spreading manure P.