1980 年 30 巻 4 号 p. 385-391
The rate of CO_2 evolution from soil, Y (mg C/kg dry soil/hr), was highly correlated with the amount of dissolved orgainc carbon in soil solution, X (mg C/kg dry soil), obtained by a centrifugalization. The rates Y of soils of a forest floor at 25℃ were almost invariably 1.5 in a wide range of the contents of soil water from 60 to 120% on an oven-dry weight basis, while those of soils of a paddy field were 0.9 in arange from 80 to 150%. The amounts X were also constant within these ranges, being about 3.7 in the soils of the forest floor and 2.6 in the soils of the paddy field. At the lower ranges of the contents of soil water, the rates Y decreased with the decrease of the amounts X. The equation Y=0.370X holded equally well both in the soils of the forest floor and in the soils of the paddy field except in the soils at extremely high contents of the soil water.