The displacement of calibration curves for electrical soil‐moisture units

Electrical‐resistance blocks were calibrated for use in soil‐moisture studies at Seabrook, N.J. Curves from successive laboratory calibrations are positioned differently because of the effects of chemical quality of the water used, drying techniques and other factors. Furthermore, the laboratory curves are displaced from the field calibration curves because of the difficulty of establishing moisture equilibrium in laboratory samples. It is believed that the results demonstrate the general unreliability of laboratory calibrations when compared with field calibrations of soil‐moisture blocks