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Using Soil Moisture Meters to Compliment Irrigation Scheduling

By Steve Miller and Younsuk Dong
 
There are several tools available for assisting irrigators in making irrigation scheduling decisions. These include paper copies on a clip board that can stay in the truck and Excel spreadsheets that assist in calculating water demand to prove graphical outputs. All scheduling methods rely on estimated crop water usage that uses a reference value of evapotranspiration (ET) (a well-watered grass) derived from weather station data that is then modified to reflect the crop being irrigated. We are developing methods to use satellite data to estimate ET and crop water stress, then making that data available to irrigators.
 
Soil moisture monitoring, once seen as a research tool, has been adapted by producers as an irrigation management tool. Measuring soil moisture near the top, middle and bottom of the crops rooting area allows producers to see the cumulative impact of irrigation and rainfall compared to the crop’s removal of water.
 
These tools are helpful but cannot replace field observations of soil moisture at multiple depths and crop conditions. Soil moisture sensors can be a valuable tool to complement irrigation scheduling. All sensors use the fact that water transmits an electrical charge or electrometric pulse better than soil. To provide useful information, the sensors must be installed in representative locations in the field, be properly installed with good contact between the sensors and the soil and the results interrupted knowing soil texture.
 
The cost of sensor systems range in price from $440 for an Irrometer handheld meter with five sensors to $3,800 for a Campbell Scientific with continuous data collection, five sensors and remote access to the data. For a detailed breakdown of examples of cost and a description of various sensors, see “Comparison of Soil Moisture Sensors Readings and Introduction of Hydrus Model from Michigan State University Extension.
 
 
An affordable sensor system is being developed that includes five sensors, a data logger and remote access to continuous data that can be viewed on a smart phone, tablet or computer. We expect the components for the system to cost about $200 and less than $30 a year for the remote access.
 
Note the green line, late season soybean crops drying of the soil 3 feet below the surface even with adequate irrigation.
 

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Why Your Food Future Could be Trapped in a Seed Morgue

Video: Why Your Food Future Could be Trapped in a Seed Morgue

In a world of PowerPoint overload, Rex Bernardo stands out. No bullet points. No charts. No jargon. Just stories and photographs. At this year’s National Association for Plant Breeding conference on the Big Island of Hawaii, he stood before a room of peers — all experts in the science of seeds — and did something radical: he showed them images. He told them stories. And he asked them to remember not what they saw, but how they felt.

Bernardo, recipient of the 2025 Lifetime Achievement Award, has spent his career searching for the genetic treasures tucked inside what plant breeders call exotic germplasm — ancient, often wild genetic lines that hold secrets to resilience, taste, and traits we've forgotten to value.

But Bernardo didn’t always think this way.

“I worked in private industry for nearly a decade,” he recalls. “I remember one breeder saying, ‘We’re making new hybrids, but they’re basically the same genetics.’ That stuck with me. Where is the new diversity going to come from?”

For Bernardo, part of the answer lies in the world’s gene banks — vast vaults of seed samples collected from every corner of the globe. Yet, he says, many of these vaults have quietly become “seed morgues.” “Something goes in, but it never comes out,” he explains. “We need to start treating these collections like living investments, not museums of dead potential.”

That potential — and the barriers to unlocking it — are deeply personal for Bernardo. He’s wrestled with international policies that prevent access to valuable lines (like North Korean corn) and with the slow, painstaking science of transferring useful traits from wild relatives into elite lines that farmers can actually grow. Sometimes it works. Sometimes it doesn’t. But he’s convinced that success starts not in the lab, but in the way we communicate.

“The fact sheet model isn’t cutting it anymore,” he says. “We hand out a paper about a new variety and think that’s enough. But stories? Plants you can see and touch? That’s what stays with people.”

Bernardo practices what he preaches. At the University of Minnesota, he helped launch a student-led breeding program that’s working to adapt leafy African vegetables for the Twin Cities’ African diaspora. The goal? Culturally relevant crops that mature in Minnesota’s shorter growing season — and can be regrown year after year.

“That’s real impact,” he says. “Helping people grow food that’s meaningful to them, not just what's commercially viable.”

He’s also brewed plant breeding into something more relatable — literally. Coffee and beer have become unexpected tools in his mission to make science accessible. His undergraduate course on coffee, for instance, connects the dots between genetics, geography, and culture. “Everyone drinks coffee,” he says. “It’s a conversation starter. It’s a gateway into plant science.”