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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 10/1/1995 Publication Date: N/A Citation: N/A Interpretive Summary: There are certain areas of the country where poultry manure has been over applied, resulting in high nitrate levels in groundwater, heavy metal accumulation in soils, high soil test P levels, and elevated concentrations of P in runoff water. The objectives of this paper were to provide information on current poultry manure management practices, to discuss potential problems associated with land application of poultry litter, and to delineate some possible solutions to these problems. Potential environmental problems associated with poultry manure can be divided into three categories: (1) leaching of NO3, into groundwater, (2) surface water runoff of P, C, metals, and/or bacteria, and (3) NH3 volatilization, which is important in acid deposition. Best management practices (BMPs) which reduce P runoff from poultry litter include vegetative buffer strips, establishment of an upper level for soil test P, feed additives to reduce dietary P requirements of poultry, and manure additives which precipitate P in the manure. At present, one of the most promising BMPs to decrease P runoff appears to be the addition of alum to poultry litter. Alum has also been shown to reduce NH3 volatilization from litter (which should decrease atmospheric acid deposition), as well as decrease fecal coliform, C, and metal runoff. Technical Abstract: Over 13 billion kg of poultry litter and/or manure are produced each year in the U.S. More than half of this manure is concentrated in five states (AR, NC, GA, Al and CA). As a result, there are certain areas of the country where poultry manure has been over applied, resulting in high nitrate levels in groundwater, heavy metal accumulation in soils, high soil test P levels, and elevated concentrations of P in runoff water. The objectives of this paper were to provide an overview of current poultry manure management practices, to discuss potential problems associated with land application of poultry litter, and to delineate some possible solutions to these problems. Potential environmental problems associated with poultry manure can be divided into three categories: (1) leaching of substances, such as NO3, into groundwater, (2) surface water runoff with high concentrations of P, C, metals, and/or bacteria, and (3) NH3 volatilization, which is important in acid deposition. Due to the low N/P ratio in litter, P runoff can be a problem even when litter is applied at recommended rates and at the proper time. Best management practices (BMPs) which reduce P runoff from poultry litter include vegetative buffer strips, establishment of an upper level for soil test P, feed additives to reduce dietary P requirements of poultry, and manure additives which precipitate P in the manure. At present, one of the most promising BMPs to decrease P runoff appears to be the addition of alum to poultry litter. Alum has also been shown to reduce NH3 volatilization from litter, as well as decrease C, and metal runoff. Decreasing NH3 volatilization lowers NH3 levels in poultry houses, resulting in better feed conversion and weight gains in broilers. |
