Chemical Property of Poultry Litter Amended with Selected Industrial and Agricultural Byproducts.

The bulk of poultry litter consists of manure and bedding materials.  When applied to the soil, litter supplies all essential plant nutrients, serves as a source of organic matter, and improves soil physical properties. Litter breaks down in the soil and its soil conditioning effect diminishes within a short time after application.  The breakdown of litter and other manures may be slowed by co-applying it with certain industrial and agricultural byproducts.  The objective of this research was to test selected agricultural and industrial byproducts for their ability to alter the pH and slow the decomposition of raw poultry litter.  Ten materials that included gypsum, quicklime, alum, aglime, cement kiln dust, and biochar were mixed with rice hull-based broiler litter at 20% (w/w) and incubated in open containers at ≈45% moisture and room temperature.  The pH and temperature of the mixtures were monitored throughout a 97-d incubation period beginning with the first hour.  The pH of the non-amended litter at incubation was 8.7 and increased gradually to 9.1 at the end of the incubation. The different byproducts altered the pH to as low as 4 and as high as 12 immediately after mixing.  These effects on pH and increases or decreases of mixture temperature suggested that the byproducts affected microbial activity and possibly manure decomposition.