Abstract
Incorporation of organic manure in sandy soils is known to improve soil properties related to agricultural production. Therefore, we studied the effect of temperature on the biodegradation of chicken manure and municipal refuse (measured by static alkali absorption of CO
2) during a series of successive 7-day laboratory incubations at 0, 10, 20, 30 and 40°C using application rates equivalent to: 0, 4·1, 8·25, 16·5 and 33·0, and 0, 16·5, 33·0, 49·5 and 66·0t ha
−1, respectively. Regression analyses revealed that a linear relationship existed between temperature and rate of biodegradation. Based on an Arrhenius plot of log rate of biodegradation vs. 1/T (reciprocal of absolute temperature), the rate constant (
k), activation energy (
E
a) and the temperature coefficient (Q
10) of the biodegradation process at each temperature and rate were calculated. The results obtained indicated that at high rates of application the magnitude of
k, E
a and Q
10 was affected by the rate, irrespective of temperature. At application rates higher than the optimum (16·5 and 33·0t ha
−1 for chicken manure and municipal refuse, respectively) biodegradation was insensitive to temperature. This effect was reflected on the calculated values of
k, E
a and Q
10. Moreover, this study revealed significant correlations between the application rates of manures and some of the properties of the manure-treated sandy soil.