Poultry Litter Decomposition as Affected by Litter Form and Rate before Flooding for Rice Production

Abstract

Environmentally sound management of poultry litter from concentrated broiler‐producing areas is a major challenge. Due to its chemical composition, poultry litter could be a valuable organic source of plant nutrients and soil amendment for row‐crop agricultural soils if transportation costs are not limiting. However, few studies have investigated the effects of poultry litter on nongraded soils used for rice (Oryza sativa L.) production in the mid‐southern United States. The objectives of this study were to evaluate the effect of poultry litter form (fresh and pelletized) and five application rates (34–269 kg N ha−1) on soil surface CO2 flux, total soil N and organic C, and inorganic soil N before flood establishment and to evaluate the effect of soil temperature and moisture on soil surface CO2 flux in two silt‐loam Aqualfs. Poultry litter decomposition dynamics, as measured by soil surface CO2 flux and total soil N and organic C concentrations in the top 10 cm, were unaffected by litter form but were generally affected by litter rate. When significant, soil surface CO2 flux, total soil N and organic C, and soil NO3–N and NH4–N increased as litter rate increased. Soil NH4–N was generally unaffected by litter form, but soil NO3–N was consistently higher from the pelletized than fresh litter when added between 134 and 269 kg total N ha−1, suggesting that pelletized litter may have a slightly greater fertilizer‐N value than fresh litter. Environmental factors, such as soil temperature and moisture, were not significant controlling factors for soil surface CO2 flux early in the rice growing season, suggesting that soil biological properties such as microbial biomass may be more of a controlling factor than moisture and temperature.