Save Water by Measuring Temp of Plants —

From (Laurie Bedord):

“With water becoming more precious, we need to exploit the potential of every tool available,” says Kendall DeJonge, an Agricultural Research Service engineer in Fort Collins, Colorado. “Using an infrared radiometric thermometer (IRT) to determine a crop’s water needs just makes sense.”

Currently in research applications, IRTs are placed on field posts or center pivot irrigation systems. Temperature readings are gathered hourly or daily on crops. Scientists then interpret the data by using one of several indices, including the crop water stress index (CWSI), which is considered the gold standard for quanti fying water stress. Developed in the early 1980s, the CWSI also requires that users know air temperatures and humidity levels.

Because the CWSI method is fairly technical and requires additional measurements, many farmers will guesstimate when to irrigate, which could mean water is wasted by overirrigating. As a result, yields will suffer because crops aren’t getting enough to drink. What farmers need is a simple, yet effective, method to monitor the water demands of a crop.

Simplified process

That’s where DeJonge comes in. The scientist has found a way to simplify the process by using canopy temperatures to determine if crops are water stressed.

His research centers around IRTs, affordable sensors that can determine the crop canopy temperature and whether a crop is water stressed.

He and his colleagues compared the CWSI with five other formulas for interpreting IRT data to see how well they could detect crop water stress over two years in a corn-sunflower rotation. All of the indices used crop canopy temperatures to determine water stress levels.

The team developed two indices for the study, which are simpler than CWSI. The Degrees Above Non-Stressed (DANS) index is calculated by comparing a stressed plant’s temperature with the temperature of a nonstressed plant in the same environment. The second study, Degrees Above Critical Temperature (DACT), is based on an established crop temperature threshold, with plant water stress determined by how many degrees above that threshold the plant temperature reaches.

Crop canopy temperatures for DANS and DACT were taken each day at 2 p.m., when water stress levels were usually highest. Researchers monitored soil water levels and crop water use. They fully irrigated part of the field, while intentionally stressing other areas.

Even though they require much simpler measurements, the findings show the DANS and DACT indices are just as effective as CWSI.

DeJonge plans to develop crop water coefficients that establish water needs of specific crops under different scenarios. With that data, IRTs could soon be widely used by farmers. He also foresees farmers using handheld IRTs in the not-so-distant future and eventually using the thermometers with drones to calculate water needs over extensive areas.


The latest “The Current” newsletter is hot off the presses from the Eagle River Watershed Council

Click here to read the newsletter. Here’s an excerpt:

While the West has transformed and evolved greatly since the pioneer days, mining laws remain largely unchanged. Hardrock mining and extraction is, to this day, governed by President Ulysses S. Grant’s General Mining Law of 1872.

Five U.S. Senators, including Sen. Michael Bennet of Colorado, have introduced the Hardrock Mining and Reclamation Act of 2015 in an attempt to reform that 140-year-old law and provide a modern mechanism by which we might cleanup abandoned mines throughout the West…

Kate is the education & outreach coordinator for the Watershed Council. Click here to read more about the proposed legislation.

Snowpack news: The Arkansas River basin = 123% (best in state)

Click a thumbnail graphic below to view a gallery of snowpack data from the Natural Resources Conservation Service.

Below is the December 1st Westside SNOTEL map from the Natural Resources Conservation Sevice.

Westwide SNOTEL December 1, 2015 via the NRCS
Westwide SNOTEL December 1, 2015 via the NRCS

Garden City: 2015 Annual Meeting Arkansas River Compact Administration, December 10

Garden City, Kansas, back in the day
Garden City, Kansas, back in the day

From email from the Arkansas River Compact Administration:

The 2015 Annual Meeting of the Arkansas River Compact Administration (ARCA) will be held on Thursday, December 10, 2015, commencing at 9:00 A.M. CST (8:00 A.M. MST) in the Clarion Inn, Garden City, Kansas. The meeting will be recessed for lunch at about 12:00 P.M. and reconvened for the completion of business in the afternoon as necessary.

The Engineering, Operations, and Administrative/Legal Committees of ARCA will meet on Wednesday, December 9, 2015, also at the Clarion Inn, starting at 2:00 PM. CST (1:00 P.M. MST) and continuing to completion. The public is invited to attend the Committee meetings, however please be aware time for comments may be limited.

Meetings of ARCA are operated in compliance with the federal Americans with Disabilities Act. If you need a special accommodation as a result of a disability please contact Stephanie Gonzales at (719) 688-0799 at least three days before the meeting.

This information is also available on ARCA’s website:

Arkansas River Basin via The Encyclopedia of Earth
Arkansas River Basin via The Encyclopedia of Earth