Development of a new manure amendment for reducing ammonia volatilization and phosphorus runoff from poultry litter

Authors: Moore, Philip

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2016
Publication Date: 6/29/2016
Citation: Moore Jr, P.A. 2016. Development of a new manure amendment for reducing ammonia volatilization and phosphorus runoff from poultry litter. Journal of Environmental Quality. 45:1421-1429.

Interpretive Summary: Treating poultry litter with aluminum sulfate is a best management practice that reduces phosphorus runoff and ammonia emissions that is used to grow over one billion broiler chickens are grown with alum in the U.S. each year. However, alum prices have increased substantially during the past decade, creating a need for cheaper products that control phosphorus losses and ammonia emissions. The goal of this research was to develop inexpensive manure amendments that are as effective as alum in reducing ammonia volatilization and phosphorus runoff from poultry litter. Sixteen manure amendments were developed using mixtures of alum mud, bauxite ore, sulfuric acid, liquid alum and water. Alum mud is the waste product that is left over from alum manufacture when produced by reacting bauxite with sulfuric acid. A laboratory ammonia volatilization study was conducted using 11 treatments; untreated poultry litter, poultry litter treated with liquid or dry alum and poultry litter treated with eight of the new mixtures. All of the litter amendments tested resulted in significantly lower ammonia emissions than the untreated litter. Dry and liquid alum reduced ammonia losses by 86% and 75%, respectively, while the eight new litter amendments reduced ammonia losses from 62 to 73% compared to the controls. Water extractable phosphorus was significantly reduced by all of the amendments. The new amendments with the most promise were simple mixtures of alum mud, bauxite, and sulfuric acid. The potential impact of these litter amendments could be enormous, since they could be produced for less than half the price of alum, while being as effective as alum at reducing both ammonia emissions and phosphorus runoff. This technology provides a cost-effective way to reduce air and water pollution while improving poultry production.

Technical Abstract: Treating poultry litter with alum (Al2(SO4)3.14H2O) is a best management practice (BMP) that reduces phosphorus (P) runoff and ammonia (NH3) emissions. Due to the environmental benefits, improvements in poultry production, and lower energy costs over one billion broiler chickens are grown with alum in the U.S. each year. However, alum prices have increased substantially during the past decade, creating a need for cheaper products that control P losses and NH3 emissions. The objective of this research was to develop inexpensive manure amendments that are as effective as alum in reducing NH3 volatilization and P runoff from poultry litter. Sixteen manure amendments were developed using mixtures of alum mud, bauxite ore, sulfuric acid, liquid alum and water. Alum mud is the residual that is left over from alum manufacture when produced by reacting bauxite with sulfuric acid. A laboratory NH3 volatilization study was conducted using 11 treatments; untreated poultry litter, poultry litter treated with liquid or dry alum and poultry litter treated with eight of the new mixtures. All of the litter amendments tested resulted in significantly lower NH3 volatilization than the controls. Dry and liquid alum reduced NH3 losses by 86% and 75%, respectively. The eight new litter amendments reduced NH3 losses from 62 to 73% compared to the controls, which was not significantly different from liquid alum; the three most effective mixtures were not significantly different from dry alum. Water extractable P (WEP) was significantly reduced by all of the amendments; three of which resulted in significantly lower WEP than with dry alum. The new amendments with the most promise were simple mixtures of alum mud, bauxite, and sulfuric acid. The potential impact of these litter amendments could be enormous, since they could be produced for less than half the price of alum, while being as effective as alum at reducing both NH3 emissions and P runoff.