Miscellaneous thoughts
concerning all methods of
irrigation scheduling
Several different techniques are available
which can be used to effectively monitor or
directly measure soil water content. Some are
extremely simple and are well worth the
investment of time and labor. Many irrigation
scheduling consultants are using these
different methods
Table 5. (Thomas W. Ley, Robert G. Stevens, Richard R.
Topielec and W. Howard Neibling)
Qualitative evaluation of soil water monitoring devices. 1 is
Least favorable while a score of 10 is most favorable.
NP Neutron Probe;
TDR Time Domain Reflectometry;
GS Gravimetric Sampling;
AP Troxler Sentry 200
-
AP;
AQ Aquaterr Probe;
TM Tensiometer;
GB Gypsum Block;
WB Watermark Block;
Disadvantages of Fixed Point Soil
Moisture Monitoring:
Several locations and depths must be monitored to
make sure your measurements are representative of
the entire field. Irrigation systems often are
extremely variable
Movement of water on the surface of the soil leaves
wet and dry spots, often within a few feet of each
other. Moving a water mark sensor or tensiometers
a few meters away might give very different
readings. Moving to a different location in the field
will likely encounter a completely different soil.