One type of gypsum block can now even be hooked up to run an automatic sprinkler system.
Gypsum blocks will tell you New technology has made an old tool for measuring soil moisture--the gypsum-block moisture sensor--more reliable than it used to be.
Gypsum blocks, which have been around for about 60 years, are simply marshmallow-like plaster of Paris cylinders that contain two electrodes.
As with other moisture sensors, it's best to put gypsum blocks in several different microclimates or soil types around your yard.
Although most gypsum blocks gradually break down and read zero after several years, they are inexpensive to replace.
Three companies are the main suppliers of gypsum blocks and related equipment in the West.