Tracers determine movement of soil moisture and evapotranspiration.
The downward movement of water in soil is a layered one. Marking a certain layer with hydrogen-isotope tracer, and watching its displacement, makes possible a water balance and gives information on evaporation and groundwater recharge.
Zimmermann
U
U
Münnich
K O
KO
Roether
W
W
Kreutz
W
W
Schubach
K
K
Siegel
O
O