Land IQ: Tracking Water Use at the Field-Scale in California

Land IQ is an Agricultural Science and Remote Sensing company based in Sacramento, California. Land IQ ET is a data-driven model for field-scale water use estimation that incorporates ground-truth data from over 80 meteorological stations and remote sensing imagery from multiple sources. Their clients include almost 40 Groundwater Sustainability Agencies (GSAs) or Irrigation Districts, they measure evapotranspiration from 35-40 different crop types, and their network covers over 3 million acres in all or parts of six key agricultural counties: Stanislaus, Madera, Fresno, Tulare, Kings and Kern.

Frank Anderson, a Senior Scientist with Land IQ, collects and analyzes data from the ground stations and provides this information as the back bone of Land IQ's data driven field-by-field ET model on a monthly basis. “We pride ourselves on collecting the most comprehensive, accurate, and highest quality data we can for our clients,” he said. Anderson is part of a larger team effort and works closely with Seth Mulder, another Senior Scientist at Land IQ, to install and maintain ground truthing stations as well as provide post-model analysis using independent evaluations.

Since November 2022, Land IQ has deployed five LI-710 Evapotranspiration Sensors in their Land IQ ET network, and they are planning a sixth. They tested the LI-710 side-by-side with the instruments at their meteorological stations.

“We wanted to deploy the LI-710 across a spectrum of crop coverages,” Anderson said, “fallow, pistachios, almonds, citrus, and alfalfa. The alfalfa is unique due to the periodic cuttings, which gives the LI-710 some variability and contrast in ET,” he added. Canopy coverage ranges from pistachios at 25% to almonds at 90%. They plan to add an LI-710 to a mature citrus grove with over 90% coverage.

They set up the LI-710 at a challenging time of year when solar power generation is low and ET values are near zero. Anderson is impressed with how easily and smoothly the sensor connects and transmits data to their existing logger system. They find the values between their stations and the LI-710 comparable. “It speaks to the robustness of the LI-710 in that it can resolve small fluxes,” he said, “we’re happy with the results and the methodologies validate each other.”

At the alfalfa field, which is located next to a dairy, they experienced issues with LI-710 filters clogging with dairy dust in foggy conditions. “We work in a caustic environment,” Anderson said, “it’s a challenge because you have the ammonia, volatile organic compounds, and dust particles.” In response, LI-COR developed a tool that helps to easily swap out filters.

Anderson sees potentially significant cost savings with the LI-710, both in terms of its price and the labor involved in setting up a station. It took two people less than an hour to add the LI-710 to an existing infrastructure, which is set on scaffolding up to 20 feet high for trees. “Because the LI-710 is an eddy covariance sensor, we still have to follow the requirements of eddy covariance, so we can’t eliminate the scaffolding,” he said, “we estimate that it will probably take 4-6 hours to install the LI-710 with our current scaffolding infrastructure.” Their existing stations require 8-12 hours to install.

Anderson, who has worked with LI-COR instruments for over 20 years, is excited about the LI 710 and its potential for their field stations. “Our whole model is based on robust ground-truthing. It makes our modeling more defensible, makes regional estimates of ET more accurate, which results in strong agreement by the end users, the growers,” he said. He sees the release of the LI-710 as a great opportunity for Land IQ and LI-COR to work together to expand their network.