Submitted to: International Journal of Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2012
Publication Date: 5/1/2012
Citation: Watts, D.B., Smith, K.E., Torbert III, H.A. 2012. Impact of poultry litter cake, cleanout, and bedding following chemical amendments on soil C and N mineralization. International Journal of Agronomy. Vol. 2012, Article ID 204629, 8 pages, doi:10.1155/2012/204629.
Interpretive Summary: Poultry litter can be used in agricultural practices as a valuable N fertility source. Recent changes in how poultry litter is removed from broiler houses as well as the increased use of chemical amendments to control environmental loss may affect N supply to crops. This laboratory study investigated whether gypsum, lime, aluminum sulfate or ferrous sulfate amendments used in conjunction with poultry litter cake, poultry litter cleanout, and bedding material would affect N release when amended to soil. Nitrogen supply to soil was affected differently depending on whether poultry litter cake, poultry litter cleanout, or bedding material was used. The greatest N release was observed with poultry litter cake, followed by the cleanout, and bedding material. This implies that N release from poultry litter sources were most likely due to the percentage bird droppings in the litter. The use of chemical amendment aluminum sulfate generally decreased N supply when added the poultry litter sources during this short-term study.
Technical Abstract: Poultry litter is a great alternative N source for crop production. However, recent poultry litter management changes and increased chemical amendment use may impact litter plant N availability. Thus, research was initiated to evaluate the effect that broiler house cake and total cleanout litter amended with chemical additives have on C and N mineralization. A 35 day soil incubation study was carried out on a Hartsells fine sandy loam (fine-loamy, siliceous, subactive, thermic Typic Hapludults) soil common to the USA Appalachian Plateau region. Three poultry litter components (cake, total cleanout, and bedding material) from a broiler house were evaluated and compared to a control. Chemical amendments lime (CaCO3), gypsum (CaSO4), aluminum sulfate (AlSO4), and ferrous sulfate (FeSO4) were added to the poultry litter components to determine their impact on C and N mineralization. Litter component additions increased soil C mineralization in the order of cake > cleanout > bedding > control. Although greater C was observed in the bedding material, poultry litter cake mineralized the most C, which can be attributed to differences in C:N ratio between treatments. Chemical amendment addition to the manured soil also impacted C mineralization, with CaCO3 increasing and AlSO4 generally decreasing mineralization. Nitrogen mineralization was significantly affected by the different poultry litter component with greater N availability being observed with cake > cleanout compared to control, while the bedding material resulted in net N immobilization. This short term study (35 day incubation) indicates that N availability to crops may be different depending on the poultry litter component used for fertilization. Also the use of chemical amendments AlSO4, may decrease the N mineralization rates thereby slowing down N availability to crops.