Influence of Chicken Manure Amendment on the Thermal Properties of Selected Benchmark Soils in Zambia

Abstract

Influence of Chicken Manure amendment on the thermal properties of selected Benchmark soils in Zambia was investigated in the laboratory under soil column experiments. Five benchmark soils were exerted to four chicken manure amendment rates of 0% (control), 2%, 4% and 6% on a weight basis. Soil temperature profiles were monitored in soil columns exerted to artificial heat source and generated data was used to compute the thermal properties of the soils. The effect of manure application on the soil thermal properties was strongly related to soil type and application rate. Significant differences (p < 0.05) were observed in volumetric heat capacity, thermal diffusivity and damping depth among the benchmark soils. The volumetric heat capacity varied from 3.87 MJ•m −3 •c −1 (Mushemi series) to 8.62 MJ•m −3 •c −1 (Makeni series) and attributed to differences in soil characteristics. Thermal diffusivity varied from 0.028 m 2 •s −1 (Makeni series) to 0.069 m 2 •s −1 (Mushemi series) a reverse trend to thermal conductivity. A similar trend was observed with damping depth however thermal conductivity was not significantly different among the benchmark soils. The studied soils showed significant differences (p < 0.05) in their thermal properties with chicken manure amendment. Thermal conductivity (λ), thermal diffusivity (D h) and damping depth (d) decreased while volumetric heat capacity (Cv) increased with increased chicken manure addition. The differences in these thermal properties were attributed to differences in soil properties. These results suggest that chicken manure application can be an important intervention in regulation of the thermal properties of the soil and consequently the thermal regime of the soil.