Precision irrigation: A must in the face of today's water issues

Friday, May 23, 2014
The Hortau WEB TX3 soil moisture monitoring station (Contributed photo)

It's no secret many Midwest farmers are having to make up for lost time this spring due to prolonged wet weather early in the year.

While water is always welcome in the agricultural industry, the soggy conditions can lead to planting delays, fertilizer leaching, root rot and other issues if irrigation isn't managed properly.

Add to the list the constant threat of water restrictions, and precision irrigation isn't a nice thing to have -- it's a necessity.

"In agriculture, we do worry about the environment," former fourth-generation farmer Doug Larson said. He heads High Plains regional operations for Hortau irrigation management systems. "Not only do we want to watch how much water we're putting on our crops to prevent wasting water and money, we want to make sure we're not affecting the environment in a negative manner. Precision irrigation helps us do just that."

Precision irrigation, for those unfamiliar, is the practice of using state-of-the-art tools to deliver the optimal amount of water to a field or orchard.

Precision irrigation practices can include a number of innovative technologies, including soil moisture sensors.

Irrigation management starts with having the proper tools and moisture monitors in place in the field.

Without the right tools, it can be difficult for growers to determine crop health, and how often to water -- putting precisely the amount of water a plant needs in the root zone.

Using a soil moisture monitoring station helps growers to do just that -- monitor their irrigation patterns, identifying when and where to irrigate.

Hortau's "smart" soil moisture monitoring system simplifies that process, putting soil measurement information at their fingertips via mobile devices and tablets. Using mobile networks and web-based technology, Hortau's soil moisture monitoring stations report to growers how crops are faring in real time -- before stresses such as drought or lack of aeration can have a negative impact on the crop.

Larson said there are a number of different ways to measure soil moisture, the most precise of which uses soil tension to detect plant stress and water availability no matter the soil type.

"Without a system in place, it's truly a guessing game," he said. "It's really difficult to know how much water a plant needs without watching the soil profile in a system like this."

Soil mapping, data aggregation

Drones, satellite imagery, GPS and other emerging technologies have helped make soil mapping a much more useful tool in recent years.

Variable rate zone maps, for example, can help read nitrogen levels, helping growers determine when and where to plant and how much fertilizer to use.

Aggregating satellite maps, yield maps and soil test data, growers are able to see a high-level overview of their operations, giving them historic data to compare over specific periods of time.

Weather stations

Adding a weather station to the field allows growers to complement soil moisture readings with real-time weather data that keeps tabs on:

-- Air temperature and degree days.

-- Evapotranspiration (ET).

-- Wind speed and direction.

-- Cumulative rainfall and intensity.

-- Humidity, barometric pressure and solar radiation.

All of the above not only helps growers make more precise irrigation decisions, but the historical data will provide insight into what worked and what didn't year after year.

Automated irrigation systems

Automated irrigation systems give growers the ability to run their irrigation systems remotely, a major benefit for operations spread across multiple locations.

From a mobile device or computer, irrigators can start their irrigation systems (no matter if they're pivots, sprinklers or drip) with the push of a button.

The automated control units can remotely open and close valves, and start and stop diesel engines or electrical motors for pumping. Installing a control unit also adds an additional layer of reporting to "smart" irrigation dashboards, reading flow meters and pressure in irrigation lines.

"I've been in farming my whole life, and for me it's amazing what we're doing," Larson said. "You look at what these guys are doing now, planting from GPS and using precision with every piece of the process. ... It's nothing like it was when I was a kid. It truly is precision agriculture, and it's fun to be part of it."

Brian Milne is a freelance writer who covers tech, agriculture and water issues. Connect with him at