Environmental Effects of Chemical Additives Used in Poultry Litter and Swine Manure

Abstract

Research into the use of chemical additives for litter or manure additives to reduce environmental pollution has focused on aluminum; calcium; and iron-containing compounds. Aluminum sulfate [Al(SO4)3·14H2O or Al(SO4)3· 18H2O, alum) has been studied extensively in the poultry industries and is currently being used by the U.S. Environmental Protection Agency (U.S. EPA) as a litter additive. Recent studies have been very promising for the use of aluminum chloride (AlCl3) in swine manure to reduce ammonia volatilization and odor. Use of phytase with aluminum chloride reduces levels of soluble P and protects drinking water from P contamination. Basic research into the use of Fe(II) and Fe(III) compounds in manure has shown possibilities for their use in odor and ammonia volatilization reduction. Calcium-containing compounds such as limestone may be attractive for utilization in the future due to their low cost. Besides these compounds, research into the use of other chemical compounds such as zeolite, antibiotics, potassium permanganate, hydrogen peroxide, sulfuric acid, chlorine, phosphoric acid, formaldehyde, yucca saponin, ZnSO4, and organic acids is continuing and there may be promise for the use of these compounds in the future. Long-term studies are needed to determine the effects of these compounds when used as fertilizer on plant absorption and soil quality.