Alum is also believed to help reduce the risk of soluble phosphorus (P) movement in surface water. Arkansas researchers, Dr. P. A. Moore, Jr. and Dr. D. R. Edwards, utilizing small field plots, found that P from alum-treated poultry manure was less soluble and leached less than in soil treated with P from untreated manure.¹
In larger paired-watershed studies they found that P runoff volume from fields receiving alum-treated poultry manure occurred in lower amounts than from fields receiving untreated poultry manure. Their research also shows that the alum had no effect on aluminum (Al) availability in soils, Al uptake by plants or Al in runoff water. They conclude that the addition of alum to poultry litter is a long-term solution to the P runoff problem.
¹Better Crops, Vol. 90, 2006, No. 3