Respiration studies on the decomposition of organic waste-amended colliery spoil

N. F.Y. Tam, Y. S. Wong

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Microbial decomposition is an important process determining the fate of organic waste in colliery spoil. Laboratory respiration studies (using modified Birch and Friend respirometers) were conducted to investigate the rate of microbially mediated decomposition in three colliery spoils after amendment of two sewage sludges (Dewmus and Yorkshire Bounty) and two animal manures (Chiguano and Poultry Manure), respectively. Addition of organic wastes significantly enhanced the microbial respiration rates especially in the two acidic Ashington and Whitwood spoils. In most amended spoil, the relationship between cumulative volume of daily hydrogen liberated and incubation time was best described by quadratic regression models. The regression coefficient provided a good index for decomposition rate. Among the four organic wastes, Chiguano treatment had the fastest decomposition rates, followed by Yorkshire Bounty and Poultry Manure. Dewmus-amended spoil exhibited the slowest decomposition rate, suggesting that this organic waste might be more resistant to microbial attack. Besides waste amendments, addition of ammonium sulphate to colliery spoil also caused a rapid increase in decomposition rate. These findings suggested that the microbial activity was mainly limited by the low nitrogen content in the control spoil. In general, the microbial respiratory activities of the three spoil types receiving the same amendment were not significantly different from each other. This finding implied that the decomposition rate of organic amendment in colliery spoil was independent of the types of spoil. At the end of the 44-day incubation period, the amount of carbon mineralized from added organic wastes varied from 10 to 37%, in the order of Yorkshire Bounty > Chiguano + Poultry Manure > Dewmus. In general, the proportion of carbon mineralized from these four organic wastes was relatively small. This reflected the slow-release characteristics of organic waste.

Original languageEnglish
Pages (from-to)25-38
Number of pages14
JournalAgriculture, Ecosystems and Environment
Issue number1-2
Publication statusPublished - Sept 1990
Externally publishedYes


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