Using Pressure Switches to Perfect Irrigation Timing

By Gabriel Bautista
Hortau Grower Support Specialist

Managing crop stress with Hortau’s patented tensiometers allows you to monitor increasing soil tension so you know when to turn the water on in order to avoid a stress event for your crops. While paying close attention to real-time data during your irrigation, the sensors will also indicate when it’s time to turn the water off to avoid leaching of fertilizers and excessive water and energy use. Over time, you can adjust your irrigation run times to achieve precise irrigation sets. This, however, requires you to keep detailed information regarding your irrigation events and works best for the person directly involved with conducting the irrigation.

Hortau provides an additional tool that will help you achieve this precision a lot sooner — the pressure switch. Hortau’s Pressure Switch will provide you with data that will not only help manage your irrigations, but also understand water movement through the soil profile. This is a great tool for growers who manage multiple irrigators since it gives them direct and transparent insight into the irrigation events.

FIGURE 1 below demonstrates an irrigation event. With only tension data points, a grower could only assume as to when the irrigator turned the water on and off. He may assume that the water was turned on at around 11:46 a.m. which led to a drop in tension 15 minutes later as indicated in FIGURE 2.

FIGURE 3 shows the assumption of the grower that the water was turned off at about 1:17 p.m. With this information, the grower might be led to believe that the irrigation set lasted about 1.5 hours. Now look at the completely different story FIGURE 4 tells us below. It was a 4.5-hour irrigation set that was initiated at 10:46 a.m. and completed at 3:16 p.m.

So how can Hortau’s pressure switch help you? For starters, being able to see the start time is important because it allows you to observe how long it takes for tension in the shallower depths to start dropping after the start of the irrigation. It can also help us understand the capillary action in our soils based on the placement of our sensors, as well as indicate how long a worker over-irrigated after reaching saturation point. In this case, the grower could instruct the irrigator to conduct a 2.5-hour set rather than their usual 4.5-hour irrigation.

Using this real-time tool, we could save water and energy, and prevent nutrient leaching by scheduling irrigation run times based on the most accurate field data. Keep in mind, this data may also be used to help a grower who might be under-irrigating as well.

About the Author

Gabriel was born and raised in Fresno County where he grew up around agriculture. Growing up he participated in FFA activities and also worked summer jobs in agriculture.

Gabriel studied Plant Science at the California State University of Fresno and has hands-on labor and management experience growing organic berries for a grower in Central California, where he currently provides grower support services for Hortau.

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