LI-COR LI-710 - Height above the Canopy

Section 2. Deploying the LI-710
Height above the canopy
The area represented in measurements from the LI-710 will depend on its height
above the plant canopy. The LI-710 should be installed at least 2 meters above the
canopy. At a 2-meter mounting height, the fetch is assumed to be a 100 to 200 meter
radius around the LI-710 (see Figure 2-3 on the previous page). All landscape ele-
ments within this range can contribute to the evapotranspiration measurement.
The LI-710 is designed for measurements over annual crops and orchards. Over fast-
growing canopies, such as soybeans, sorghum (milo), wheat, flax, rice, maize (corn),
vegetables, and cotton, install the LI-710 at 3.5 to 5 meters above the surface before
germination for a fetch up to 350 to 500 meters. As the crop grows, the distance
between the canopy and sensor will become smaller, and so will the fetch. This is an
ideal measurement scenario - the area measured represents the area-of-interest for the
entire growing season. Alternatively, you can raise the height of the LI-710 over the
growing season to maintain a consistent measurement height.
Figure 2-5. The LI-710 can be installed at a fixed position over crops. Install it at a height
that is at least 2 meters above the expected canopy height. Alternatively, you can raise the
LI-710 as the crop grows to maintain a consistent height for the season.
2-4 LI-710 Evapotranspiration Sensor Instruction Manual