An improvement in lysimeter design
1940
Wallihan, E.F.
Four small lysimeters were asembled in a greenhouse. Two were allowed to drain by gravity, according to the usual procedure. In the other two drainage was aided by the application, through tensiometers cups, of a tension equivalent to about 10 cm of mercury column. As a result of this improved drainage, the rate of evaporation of water from the lysimeter was decreased, volume of percolate increased, content of nitrates and calcium in percolate increased, and growth of plants decreased. Since this procedure rendered moisture conditions more nearly like those occurring in naturally well-drained soils, it was concluded that the abnormal moisture conditions in the ordinary type of lysimeter cause important errors in lysimeter studies. The method used here for correcting these conditions appears to offer possibilities for general use in lysimeter installations.
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