Impact of Poultry Litter Cake, Cleanout, and Bedding following Chemical Amendments on Soil C and N Mineralization

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 its N availability. Thus, research was initiated to evaluate the effect that broiler cake and total cleanout litter amended with chemical additives have on C and N mineralization. A 35-day 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 (broiler cake, total cleanout, and bedding material) from a broiler house were evaluated and compared to a soil control. Chemical amendments lime (CaCO 3 ), gypsum (CaSO 4 ), aluminum sulfate (AlSO 4 ), and ferrous sulfate (FeSO 4 ) 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 broiler cake > total cleanout > bedding > soil control. Although a greater concentration of organic C was observed in the bedding, broiler cake mineralized the most C, which can be attributed to differences in the C : N ratio between treatments. Chemical amendment in addition to the manured soil also impacted C mineralization, with AlSO 4 generally decreasing mineralization. Nitrogen mineralization was also significantly affected by poultry litter component applications. Broiler cake addition increased N availability followed by total cleanout compared to soil control, while the bedding resulted in net N immobilization. Chemical amendments impacted N mineralization primarily in the broiler cake amended soil where all chemical amendments decreased mineralization compared to the no chemical amendment treatment. 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 and chemical amendment use which could decrease N mineralization.