Soil Type and Temperature Affect Poultry Manure Residual Nitrogen Mineralization.

Residual nitrogen (N) from poultry manure continues to mineralize through the inter-season period.  Soil temperature and moisture affect the rate at which either freshly applied or residual N is mineralized.  Residual N mineralization varies among soils receiving the same organic material.  Different soil types will have distinct rate of residual N mineralization from poultry manure when the temperature changes.   Determining residual N amount and mineralization rate can be used in calculation of nutrient requirement for the succeeding crop.  This study seeks to determine how application time, N source, temperature and soil type (Goldsboro loamy sand, Norfolk loamy sand and Portsmouth fine sandy loam) affect poultry manure (broiler litter and layer manure) residual N mineralization rate.  End season soil samples collected from wheat and cotton-corn-cotton rotation fields that received 134 kg N ha^-1 from poultry manure.  Check plot soils were also collected.  These soils were aerobically incubated under controlled temperature chambers at 10, 20 and 30 ⁰C while maintaining moisture at 80% container capacity.  Two control treatments were included, check-plot soils with and without fresh addition of urea at 134 kg N ha^-1.  Mean response for 10, 20 and 30 ⁰C temperatures were used to calculate amount and rate of N mineralized from the soil types in SAS Proc Nlin and Proc Glimmix.  Residual N mineralized ranged between 4.3-9.8 kg N ha^-1 with 10 ⁰C giving the lower amount than 20 ⁰C and 30 ⁰C.  The mineralization rate was between 0.01-0.25 kg N ha^-1 day^-1 (p=0.05).  Increase in temperature corresponded to the maximum amount of N mineralized but not the rate of mineralization.  Application time and N source did not significantly affect residual N mineralized