Installing Soil Moisture Sensors
Page 11
Sprinkler Irrigation
• Sprinkler irrigation usually provides a more uniform distribution of
water to the ground surface, but there can be great differences in pene-
tration and holding capacity due to soil type variations, soil interfaces
and contour. Try to place your sensors in the areas where variations
occur.
• In tree crops, locate sensors at the drip line.
• In row crops, locate sensors right in the plant row.
• Be sure that sensors are not located behind obstructions, such as tree
limbs, which would interfere with water distribution to the sensor area.
• With center pivots, place sensors at 4 locations down the length of the
pivot, just in front of the "start" point.
• Place sensors at "hot spots" or "good production" areas being sure to stay
in active root zones.
Drip or Micro Irrigation
• Place sensors in the wetted area. With drip emitters, this is usually 12” to
18” from the emitter.
• With micro-sprinklers or sprays, usually 24” to 36” from the micro-sprin-
kler is best.
Sensor Depths
Sensor depth depends on the rooting depth of your crop, and also depends on
soil depth and texture.
• With shallow rooted (less than 12”) vegetable crops, one depth may be
adequate.
• Deeper rooted row crops, small grains, vines, and trees need to be mea-
sured in at least two depths.
• With deep well-drained soils, crops generally root deeper if moisture is
available.
