Relationship of soil and water is generally considered as important in soil science. To specify it further we studied two different soils in 2012-2013, three additional soils once and made several series of experiments with drying and wetting of the soils. Principal parameters studied were the gravimetric water content (GWC), water holding capacity (WHC), soil organic matter (SOM), their correlations and rates of change in drying or wetting. The three parameters are significantly intercorrelated. Distribution of GWC in the replicates of soils dried both in nature and in experiments was narrower than that in wet soils, while WHC changed less in drying. The correlations (GWC-WHC) became steeper (the slope coefficient higher) and the coefficient of determination (R 2) lower. Attempts to increase WHC in wet soils with a high WHC even further were not successful. Drying may be fast or slow; rates of increase of WHC in wetting were all low, both in field and in the experiments, less than 0.1 g (H2O) g −1 (soil)•day −1. None of the three parameters can be considered as fixed characteristics of forest soils.

Drying of soil was linearly related to time, soil volume decreased and ratio of air within the soils increased. Respiration was related with decreasing humidity, storage of CO2 in soil water results in RQ < 0.5 in the larger soil items at least for a while. Rate of drying decreased in the second part of the process. RQ increased as the CO2 stored was aerated when its solvent-water evaporated and access of air into the soil increased; eventually RQ = 1.0 in the last days of the experiment. Respiration of the experimental soil stopped when GWC reached 0.15. ΣRQ for the whole process is about 0.7, a bit higher in experiments with less soil suggesting less anoxia.

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