STUDIES OF THE EFFECT OF SIMULATED ACID-RAIN ON THE ECOLOGICAL EQUILIBRIUM OF THE SOIL SYSTEM .2. SOIL AS A PHYSICAL-ENVIRONMENT - FLUCTUATIONS OF WATER-RESOURCES IN SOIL DURING THE VEGETATION PERIOD
M. Angiel, STUDIES OF THE EFFECT OF SIMULATED ACID-RAIN ON THE ECOLOGICAL EQUILIBRIUM OF THE SOIL SYSTEM .2. SOIL AS A PHYSICAL-ENVIRONMENT - FLUCTUATIONS OF WATER-RESOURCES IN SOIL DURING THE VEGETATION PERIOD, Environmental monitoring and assessment, 41(1), 1996, pp. 15-37
During the vegetation periods of the years 1988 and 1989, within studi
es performed at Dziekanow Lesny near Warsaw, the temporal variation of
humidity and water resources in the upper soil layer (loamy sand) was
determined. Two experimental plots were observed: one subject to natu
ral precipitation and the other watered with natural + simulated preci
pitation (8.4 mm weekly). In the vegetation period of a year which had
a dry spring and autumn and wet summer (1988), neither of the experim
ental plots showed overdrying of the upper 10 cm soil layer. During 96
% of the time, at both experimental plots, water accessible to plants
and gravitation water was found. On the other hand, in the vegetation
period of a year with a wet spring and autumn and a dry summer, water
conditions were different; accessible water and gravitation water occu
rred at the experimental plot, alimented with natural precipitation du
ring 80% of the time, and at the plot watered with natural + simulated
precipitation only during 57% of the time. In the case of rain defici
t, small artificial watering in the summer had enhanced evaporation an
d decreased the water content in the nearsurface soil layer.