The Importance of Distribution Uniformity
Distribution uniformity values most growers consider “good enough” could still be costing $700 per acre.
This fall, Team Tule was pleased to join the Almond Board of California on their Irrigation Workshop Series. We spoke to growers all over the state about the differences between Reference Evapotranspiration (i.e., the water use of a lawn) and Actual Evapotranspiration (i.e., the water use of your crop field) and the importance of irrigating to Actual Evapotranspiration.
I enjoyed learning from the other speakers at the ABC workshops. My favorite was the presentation by the Almond Board’s Tom Devol called, “Importance of Distribution Uniformity and Cost of Leaks.” In the presentation, ABC’s Field Outreach & Education Senior Manager discusses the hidden cost of poor distribution uniformity.
At Tule, we’ve long touted the importance of monitoring and improving distribution uniformity along with measuring and irrigating to Actual Evapotranspiration. They’re both important tools when it comes to irrigating efficiently and maximizing the profitability of your operation.
Putting a Number on Issues
Missing Sprinkler
.87 GPH
52.2 GPH
46,771 gallons in a season of irrigation.
Improper Repair
.21 GPH
12.6 GPH
11,290 gallons in a season of irrigation.
Leaks at Filter
.61 GPH
36.6 GPH
20,773 gallons in a season of irrigation.
Clogged Screens
Lose of 12 PSI in system pressure.
What’s more, if you’re using an in-line pressure switch to monitor irrigation applications, like the one on the Tule sensor, having good distribution uniformity is key to getting the most from the data.
Take a look at Tom Devol’s Distribution Uniformity presentation here.
A leak here and a leak there can add up to significant water costs and crop loss. But did you know that poor distribution uniformity can cause overall over-irrigation to overcompensate for under-irrigated areas? That can lead to excess water bills, pumping costs, and nutrient leaching.
In one of Tom’s examples, he shows that a distribution uniformity reduction from 100% to 85% in a 100-acre almond orchard can cost a grower up to $70k in a year. And that’s where water is cheap! And not including ineffective nutrient applications!
Simple Math on 100 Acres
Lost Yield
$655.00 per Acre x 100 Acres…..$65,500.00
Additional Water Applied
$36.00 per Acre x 100 Acres………..$3600.00
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TOTAL……………………………………………..$69,100.00
Tom Devol’s presentation is geared toward almond growers, but the pitfalls of low distribution uniformity plague any irrigated crop. Now is a great time to conduct a distribution uniformity test on your ranch! Need help monitoring your distribution uniformity? Many Resource Conservation Districts conduct DU tests for free! Contact your local RCD here or contact Meras Water Solutions.
November 15, 2022 @ 12:54 pm
Having read this I believed it was very informative. I appreciate you taking the time and energy to put this information together. I once again find myself personally spending way too much time both reading and posting comments. But so what, it was still worthwhile!
December 31, 2022 @ 6:25 pm
Thank you, Nathaniel! We’re so glad you found it informative.