Carbon and nitrogen mineralization in soil amended with non-tabletized and tabletized poultry manure

Abstract

The recycling of poultry (Gallus gallus domesticus) manure (PM) needs to be done in a manner that will not only improve soil physical, chemical and biological properties but also minimize environmental risks. Untreated PM is more difficult to handle and more expensive to apply than granular fertilizers; the application of PM in the form of tablets may be a suitable alternative. It is necessary to determine whether C and N mineralization in tabletized PM (T-PM) differs from non-tabletized PM (NT-PM). Net C and N mineralization from a Brandon loam soil (Typic Endoaquoll) amended with NT-PM and T-PM, were measured in an incubation study at 25 °C. After 60 d of incubation, about 62 and 77% of total PM carbon was mineralized in NT-PM and T-PM amended soils, respectively. Carbon mineralization was not stimulated by the addition of PM tablets containing NPK to soil, while in soils mixed with NT-PM + NPK, soil respiration was reduced. Net N mineralization was similar in soils amended with T-PM and NT-PM, although changes in ammonium (NH4+–N) concentrations during incubation differed. Generally more NH4+–N accumulated in soil amended with T-PM and T-PM + NPK than with NT-PM and NT-PM + NPK The concentrations of nitrate (NO3−–N) did not differ in soils amended with T-PM and NT-PM, indicating a reduction in nitrification and NH4+–N accumulation in soils amended with PM tablets. Key words: Poultry manure, tablets, carbon mineralization, nitrogen mineralization, organic fertilizer