Applying Poultry Litter in the Fall to Fertilize Corn May Not Be Advisable Under Warm Climate.

Row crop farmers prefer to apply poultry litter in the fall or winter but whether this practice is safe environmentally and effective for production in regions with warm fall and winter months is not well researched and document.   A research in Mississippi tested the effectiveness of fall- versus spring-applied broiler litter for corn grain production.  The research compared 9 and 18 Mg/ha poultry litter applied in the fall against the same fertilizations applied in the spring in 2006 to 2008. A treatment fertilized with 202 kg N/ha/yr as NH4NO3 (Std) in the fall and spring was included for comparison purposes.  Applying 18 Mg/ha litter in the fall reduced grain yield by 10 to 14% relative to spring application.  The reduction was even greater (12 to 17%) when the litter rate was 9 Mg/ha.  Relative to the Std, fertilization with the largest litter rate of 18 Mg/ha, whether applied in the fall or spring, produced up to 24% less grain in the first year in 2006 but produced 10 to 20% more grain in the subsequent 2 yr.  This likely is because the effect of the litter applied in the first year carries over to subsequent years.  These results clearly showed that broiler litter may be an effective corn fertilizer if applied in the spring.  Applying litter in the fall to fertilize corn is not advisable under relatively warm climate conditions such as that of northern Mississippi.