ISSN:
1435-0661
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
2 and inorganic N. First-order kinetic models described the accumulation of CO2 and inorganic N and accounted for 96 to 99% of the variation in these processes. First-order rate constants (k) for net N mineralization significantly increased with temperature, but the k for microbial respiration did not increase in a consistent manner; it was 0.107 wk-1 at 5°C, 0.123 wk-1 at 10°C, and 0.101 wk-1 at 25° C. Matric potential did not significantly influence k for either process. Substrate pools for microbial respiration and net N mineralization declined between -0.01 and -0.30 Mpa, and the decline was greatest at the highest soil temperature; this response produced a significant temperature-matric potential interaction. We conclude that high rates of microbial activity at warm soil temperatures (e.g., 25°C) are limited by the diffusion of substrate to metabolically active cells. This limitation apparently lessens as physiological activity and substrate demand decline at relatively cooler soil temperature (e.g., 5°C).
Type of Medium:
Electronic Resource
