Nutrient Fate in the Full MAnure PHosphorus EXtraction (MAPHEX) System, and Design of a Simplified System (MAPHEX Lite)

Abstract

Highlights The MAPHEX System removes and concentrates most of the P and other nutrients from liquid dairy manures. Most of the N and K are left in the liquid fraction for the beneficial use of the farmer. Design and expected performance of a simplified but much larger System is discussed. Abstract. The relatively recent concept of the manureshed highlights the problem of the broken nutrient cycle in modern animal agriculture and the low nitrogen:phosphorus ratio in manure relative to crop requirement that results in P accumulation in soils near source areas. One solution to avoid P accumulation is to transport the manure to soils with a deficit of P, but liquid manure’s bulkiness and low nutrient density present challenges for transport over great distances. While the full MAnure PHosphorus EXtraction (MAPHEX) System has shown to be capable of removing greater than 90% of the P from liquid manures while leaving much of the N in the liquid fraction for use on the farm, other nutrients present in manures in lesser amounts than N and P have not been reported on. This study indicates that both the full MAPHEX System and a newly designed MAPHEX Lite System, that not only conserves more N but is more efficient and less costly, are highly efficient at extracting and concentrating most nutrients in solid form while leaving most of the N and K in the liquid phase for beneficial use by the farmer near the manure source. Therefore, it seems clear that both Systems, and the components they include have the potential to play a significant role in manureshed management. Keywords: Chemical treatment, Liquid-solid separation, Manure, Nitrogen, Phosphorus, Potassium, Treatment systems.