Monday, November 2, 2009
Convention Center, Exhibit Hall BC, Second Floor
Georgia generates an average of two million Mg poultry litter (PL) annually. While this material is used as a fertilizer, its nitrogen (N) value could decrease considerably due to ammonia (NH3) volatilization. One possible way of minimizing NH3 volatilization from PL is by mixing it with biochar (or char), a by-product from bio-fuel production. When acidified, biochar may reduce NH3 losses from PL. This study aimed to 1) evaluate the effect of acidified biochar on NH3 volatilization, 2) examine its effect on CO2 evolution and 3) determine its influence on the release of inorganic N and P from surface-applied or incorporated PL. Poultry litter with or without acidified biochars was surface-applied or incorporated into the soil. During the 21-d incubation, volatilized NH3 and CO2 evolved were determined at certain periods. Inorganic N and P were determined by leaching the soil with 0.01 M of CaCl2 followed by a N- and P-free nutrient solution at 14 and 21 d of incubation. In addition to leaching, the treatments were extracted with 1 M KCl at the end of the incubation. Acidified biochars reduced NH3 losses by 63% and CO2 evolved by 21% from surface-applied PL. Similarly, it decreased NH3 volatilized by 60% but increased CO2 emission by 37% from incorporated PL. Adding acidified biochars did not affect the release of inorganic P from surface-applied or incorporated PL. Acidified biochars did not affect inorganic N released when PL was applied on the surface but increased it when PL was incorporated into the soil.