Abstract:
One of the major issues in the poultry industry is the large-scale waste accumulation, which can lead to disposal and pollution problems. Due to high nitrogen content, poultry droppings can be used as a nitrogenous soil amendment after composting. However, up to 50 - 88% of the total nitrogen (TN) may be volatilized as ammonia (NH3) during decomposition. This study aims to evaluate the effectiveness of different levels of single super phosphate (SSP) as additives to mitigate NH3 emission during decomposition of poultry droppings. Poultry layer droppings within seven days were collected as the raw material and allowed to decompose for 42 days. Five treatments were designed with varying levels of SSP addition: 0%, 22%, 26%, 30%, and 34% on a dry weight basis, as T1, T2, T3, T4 and T5, respectively. Treatments were tested in a completely randomized design with four replicates. Samples were collected on the 0, 14th, 28th, and 42nd day from each pile and pH, EC and TN were measured. The NH3 emission was determined in the laboratory by enclosure venting method. ANOVA was adapted in data analysis and means were compared by using Dunnett’s Test at 5% probability level. Initial poultry droppings had 4.5% TN. The pH and EC were 8.0, and 1.0 mS/cm, respectively. There was no significant difference (p > 0.05) in TN and NH3 emissions among treatments on 14th and 28th days. The pH ranged from 8.4 to 8.6, and the EC ranged from 6.6 to 9.2 mS/cm in all treatments on day 42. On 42nd day, the significantly higher (p < 0.05) values for TN (2.2% and 2.3%) were obtained by T4 (30% SSP) and T5 (34% SSP) respectively, compared to control (T1). Meanwhile, lower values of NH3 (138.7 mg and 151. 9 mg) was obtained by T4 (30% SSP) and T5 (34% SSP), respectively. Therefore, T4 is the optimum amount of SSP added poultry dropping treatment (30% SSP), which is an effective way to increase the TN while reducing NH3 emission.
