Drying Poultry Manure for Pollution Potential Reduction and Production of Organic Fertilizer

Abstract

Disposal and storage of raw poultry manure has become an environmental problem because of the associated air, water and soil pollution. Poultry manure begins to decompose immediately after excretion giving off ammonia which, in high concentrations, can have adverse effects on the health and productivity of birds as well as the health of the farm workers. Application to land is the most common way for utilizing poultry manure as a viable source of major plant nutrients and soil conditioner to improve soil tilth and reduce the problems associated with soil compaction. The aim of this study was to investigate the effects of drying depth and temperature on the nutritional profile of dried poultry manure and its suitability as a plant fertilizer. Drying temperature and manure depth had no significant effects on manure pH, but the loss of ammonia during the drying process decreased the pH (from 8.4 to 6.4-6.7). Greater nitrogen losses (44-55 %) were observed at the deeper manure layer (3 cm) and the higher temperature (60°C) which resulted in a reduction of N:P:K (from 4.58:1.29:1 to 2.07:1.30:1-2.57:1.28:1). Drying of poultry manure helped reduce the presence and offensiveness of odor by 65.3 and 69.3%, respectively. Drying of poultry manure also achieved significant reductions in bacteria (65.6-99.8%), yeast and mold (74.1-99.6%) and E. coli (99.97 %). Dried poultry manure can be used as a fertilizer source for plants because of its high nitrogen, phosphorus and potassium contents which are essential for plant growth. Other elements (such as calcium, magnesium, sulfur, boron, copper, iron, manganese, molybdenum, cobalt and zinc) which are lacking in commercial fertilizer are also present in manure in significant amounts.