Soil Sensors a Smart Choice


Employing irrigation technology can boost your sales and reduce clients’ water bills

Technology is not just for desk jobs anymore – it’s everywhere, including the properties you service every day. If it’s not an integral part of your grounds and landscaping practices, it should be.

Water bills from a property owner in Palm Beach Florida show how a soil sensor can benefit you and your client.

Here’s why.

Soil moisture technology has come a long way since it was first introduced. It’s relatively simple to install, creates the optimal environment for landscaping and lawn health, and when it’s installed correctly and in appropriate landscape settings, it can save 20 percent to 50 percent of your customers’ water and water bill – sometimes more – over non-automated systems. Who doesn’t want a quick return on their investment?

Soil sensors often measure more than moisture for turf managers who need additional information. Growing in popularity are small, wireless sensors that measure salinity and temperature in addition to moisture.

Here’s how the technology works:

1. The sensors are buried in each irrigation zone, 2 to 18 inches beneath the surface, depending on the brand and the quality of the product.

2. A base station is connected to the existing irrigation clock, and becomes the “brains” of the clock, or a controller replaces an existing clock.

3. The base station or controller adjusts to the type of soil in which the sensors, carefully calibrated, have been buried, so it “knows” the optimal moisture zone for that particular soil type.

4. The sensors measure the soil conditions regularly and send the soil data, in the case that they are wireless, to the base station to let it know what the moisture levels are for each zone.

5. The microprocessor in the base station or controller determines how long to run each irrigation valve to maintain the optimal moisture level in each zone.

Irrigating to plant needs

The installation and use of soil moisture sensors increase irrigation efficiency, which is critically important in this era of rising water costs and landscape irrigation restrictions. Sensors provide an accurate answer to the question, “Am I watering enough?”

In an independent survey, 98 percent of people responded that they do not overwater and believe that they water just the right amount. However, studies show that as much as 70 percent of irrigation water is wasted because of overwatering.

While all landscapers and grounds managers can make educated estimates on how much water is needed, they really don’t know for sure. Guesswork doesn’t work. Because soil sensors are measuring the moisture in real time, they provide an accurate reading of exactly how much and when watering is needed.

Sometimes there’s confusion about soil moisture sensors and EvapoTranspiration (ET) devices. ET is based upon complex algorithms, and there’s a vast difference between an ET system and soil moisture sensors.

This particular sensor featureswireless-sensor- networktechnology that offers soil moisturedata up to six times an hour.


Think of it this way: You are on a long road trip with friends and you need to know how much gas is in your tank. You can estimate the amount of gas left in the car by calculating average speed, head wind, how many hills you’ve gone up and down, your acceleration speed and other factors. Or, you can look at your gas gauge and know exactly how much gas is left in the tank.

Soil moisture sensors are like the gas gauge; ET is like estimating how much gas is left in your tank.

Soil moisture sensors, because they are buried in the soil and measure the actual moisture, and not an estimate of the moisture, give you a precise, accurate and real-time knowledge of the moisture content.

7 Tips for Installing Soil Moisture Sensors

1.)Soil in the area of burial should be representative of the entire irrigated area.

2.)Units should be buried in the rootzone of the plants to be irrigated because that’s where the plants will extract water.

3.)Sensors need to be in good contact with the soil after burial. There should be no air gaps surrounding the sensor. Soil should be packed firmly, but not excessively, around the sensor.

4.)If one sensor is used to control the entire irrigation system, it should be buried in the zone that requires water first to ensure that all zones get adequate irrigation. Typically, this will be an area with full sun or the area with the most sun exposure.

5.)Bury units at least 5 feet from the home, property line or an impervious surface (such as a driveway) and 3 feet from a planted bed area.

6.)Locate sensors at least 5 feet from irrigation heads and toward the center of an irrigation zone.

7.)Avoid burying sensors in high traffic areas as you want to prevent excessive compaction of the soil around them.

Source: “Smart Irrigation Controllers: How Do Soil Moisture Sensor (SMS) Irrigation Controllers Work?” by Michael D. Dukes, Mary Shedd and Bernard Cardenas-Lailhacar. Access the entire document at

Be an irrigation superhero

Believe it or not, this technology can turn you into a superhero with your customers and expand your business. Here is what you need to convey to residential and business owners so that they understand what the technology can do.

1. With soil moisture sensors, your customer’s landscape suddenly turns into a savings plan. While there is no downside to the installation because the technology is wireless, there is also only upside for their wallets and green sensibilities.

2. Explain to customers that their water and monetary savings after installation typically range from 20 to 50 percent, but in some climates have well exceeded 50 percent, making their ROI somewhere in the neighborhood of six to 18 months.

3. While you know all about how overwatering causes disease and compromises the optimal environment for growing healthy plants, your customers are unlikely to truly understand that. By explaining to them how this technology takes the guesswork out of watering, they can see how their landscaping investment will be protected. By eliminating overwatering, their lawns and plants are healthier.

4. When you introduce the way in which soil moisture sensors work, let them know that while a simple irrigation clock works well to automate the times that the grounds are watered, it cannot know anything about what is actually happening in the soil, whether that spot under the trees really has too much water at the current setting, or when in fact it’s rained the day before and no water is needed at all. With wireless soil moisture sensors, all guesswork is removed.

5. Finally, be sure to bring along all the supporting documents and case studies from the company to show the customers examples of how and where the technology is being used, and most importantly, to demonstrate the savings. Many companies have this information on their websites for you to download, and if they don’t, they will likely be happy to provide you with what you need if you call them.

By providing simple-to-understand, consumer-friendly graphs (Figure 1), you can show your customers exactly what others have saved and what they too could save. Proven savings such as these helps you do your job better, grow your business by keeping happy customers and stay on top of the latest technologies working for you.

Mark McCarel is vice president of product marketing and field operations at UgMO Technologies in King of Prussia, Pa.