DAVIS Leaf & Soil Moisture/Temperature Station for Vantage Pro2 - Manual (Page 15)

15
Sprinkler Irrigation
• Sprinkler irrigation usually provides a more uniform distribution of water to the
ground surface, but there can be great differences in penetration 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 3 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-sprinkler 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 measured in at
least two depths.
• With deep well-drained soils, crops generally root deeper if moisture is available.
• With coarse, shallow or layered soils, root systems may be limited in depth.
Sensor depth
dependent on:
• crop rooting
depth
• soil texture
and depth
Co-locate
temperature probes
and
moisture sensors
Some crops need
measurement at
more than one depth
Sensors must be located in the effective root system of the crop