rather complicated measurements and procedures, this method is so far not very widespread. 2.8.223 Electrical resistance blocks The electrical resistance between electrodes embedded in ab bblock of water-absorbent material varies with its moisture content. If such a block is brought in good contact with the surrounding soil, a moisture equilibrium between the soil and the block will establish and the resistance measured between the electrodes can be empirically related to the soil moisture potential. Similarly, a calibration against the gravimetric method may allow the conversion of electrical resistance values to soil-water content. Individual calibrations should be made for each block and every particular soil, but the calibration procedure maybe simplified provided the blocks are sufficiently homogeneous. However, errors are also encountered because of the
