Fate of nitrogen during composting of chicken litter

• Published in: Environmental pollution (1987) Vol. 110; no. 3; pp. 535 - 541
• Main Authors: TIQUIA, S. M, TAM, N. F. Y
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier 01.12.2000
• Subjects: Agriculture, rearing and food industries wastes; Agronomy. Soil science and plant productions; Applied sciences; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Biotechnology; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Industrial applications and implications. Economical aspects; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Pollution; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Wastes; Organic carbon; Organic matter; Waste treatment; Nitrogen compounds; Farmyard manure; Time variation; Carbon nitrogen ratio; Vertebrata; Composting; Upgrading; Chemical composition; Agricultural waste; Biological treatment; Aves; Animal waste; Rearing by-product; Nitrogen fertilizer
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/S0269-7491(99)00319-X

Chicken litter (a mixture of chicken manure, wood shavings, waste feed, and feathers) was composted in forced-aeration piles to understand the changes and losses of nitrogen (N) during composting. During the composting process, the chemical [different N fractions, organic matter (OM), organic carbon (C), and C:N ratio], physical, and microbial properties of the chicken litter were examined. Cumulative losses and mass balances of N and organic matter were also quantified to determine actual losses during composting. The changes in total N concentration of the chicken litter piles were essentially equal to those of the organic N. The inorganic N concentrations were low, and that organic N was the major nitrogenous constituent. The ammonium (NH(4)(+))-N concentration decreased dramatically during first 35 days of composting. However, the rapid decrease in NH(4)(+)-N during composting did not coincide with a rapid increase in (NO(3)(-)+NO(2)(-))-N concentration. The concentration of (NO(3)(-)+NO(2)(-))-N was very low (<0.5 g kg(-1)) at day 0, and this level remained unchanged during the first 35 days of composting suggesting that N was lost during composting. Losses of N in this composting process were governed mainly by volatilization of ammonia (NH(3)) as the pile temperatures were high and the pH values were above 7. The narrow C:N ratio (<20:1) have also contributed to losses of N in the chicken litter. The OM and total organic C mass decreased with composting time. About 42 kg of the organic C was converted to CO(2). On the other hand, 18 kg was lost during composting. This loss was more than half (59%) of the initial N mass of the piles. Such a finding demonstrates that composting reduced the value of the chicken litter as N fertilizer. However, the composted chicken contained a more humified (stabilized) OM compared with the uncomposted chicken litter, which would enhance its value as a soil conditioner.