Revolutionizing efficiency for growers

Your best practice | Fall 2023
By Vasudha Sharma

Irrigation is a critical aspect of farming that has seen significant advancements in recent years. As water resources become scarcer and more valuable, growers are turning to smart irrigation technologies to maximize efficiency and improve the effectiveness of their irrigation events. In this article, we will explore how these innovations are transforming the way growers manage their water, reduce costs and optimize crop yields.

Before delving into the world of smart irrigation, it’s essential to understand the challenges associated with traditional irrigation methods. Conventional irrigation relies on manual labor and often lacks precision in water distribution. Many growers rely on fixed schedules or guesswork to determine when and how much to water. Additionally, the unpredictability of weather patterns can lead to overwatering or underwatering, both of which can harm crop health and yield.
What is irrigation water management?

Irrigation water management is the timing and regulating of irrigation water applications in a way that satisfies the crop’s water requirement without wasting water, plant nutrients or energy and without degrading the soil. It means applying water according to your crop needs and how much your soil can hold. The first step in good irrigation water management is knowledge of your soil type and crop water use.

When it comes down to it, irrigation scheduling is simply a decision of when to irrigate the crop and how much water to apply. There are different smart irrigation tools that decision-makers can use to develop their irrigation strategies. These tools help in estimating or measuring the soil water depletion in the crop root zone. To set up and operate an effective irrigation scheduling program, the following steps need to be followed for each field:

  • Determine the crop’s active rooting depth and the corresponding available water-holding capacity for each soil type in the field.
  • Select the predominant soil types that should be used for irrigation water management purposes.
  • Define the management allowable soil water depletion limits for the selected soil types and the crops to be grown.
  • Establish a soil moisture monitoring system and regularly (at least twice a week) keep track of the soil water deficit or depletion (two main methods to measure or estimate soil water depletion are listed later in the article).
  • Initiate an irrigation event when the soil water deficit is expected to approach the selected management allowable soil water depletion limit by the time the irrigation cycle is completed.

The power of data

Smart irrigation technology leverages the power of data to manage water. By incorporating sensors, weather forecasts and automation, growers can make informed decisions about when, where and how much to irrigate. Here’s how it works.

Soil moisture sensors: These sensors are placed in the soil to measure moisture levels accurately. They provide real-time data on soil conditions, allowing growers to determine precisely when irrigation is needed. This technology prevents overwatering, reduces water wastage and promotes healthier root systems.
Weather forecast integration: Smart irrigation systems can access local weather forecasts and adjust watering schedules accordingly. They use weather data to estimate crop water use over time and calculate when to replace it through irrigation. The general approach to weather-based methods is to maintain a running balance of current soil moisture available (or depletion/deficit relative to field capacity) to the plant by keeping track of the evapotranspiration losses and the additions from irrigation and precipitation. One thing that growers should note here is that the weather-based method estimates soil water or soil depletion instead of measuring a physical aspect of it, so it is very important to periodically validate the estimations by measuring a physical parameter such as the soil moisture using soil moisture sensors. There are a variety of weather-based irrigation scheduling tools, most are state-specific. One example is the irrigation management assistant tool used in Minnesota. IMA is automated irrigation software that works on the weather-based irrigation scheduling method’s principles as described in this article.

By harnessing the power of data, automation and precision, growers can optimize their water use, reduce costs and increase crop yields.

Automated irrigation: Growers can program smart irrigation systems and integrate the systems mentioned earlier to operate automatically, eliminating the need for manual intervention. This is especially beneficial for large-scale operations where consistent watering is crucial. Growers can remotely monitor and control their irrigation systems using smartphones and tablets. This flexibility allows for quick adjustments based on real-time data, no matter where the grower is located. Many irrigation companies provide integrated packages to manage irrigation, using soil moisture sensors, weather data and automation to remotely manage irrigation on multiple fields.

Precision irrigation or variable rate irrigation

Variable rate irrigation is an advanced precision irrigation technique that allows for the customized adjustment of water application rates across a field or agricultural area based on specific spatial variations in crop needs, soil characteristics and other relevant factors. VRI systems use a combination of technology, including GPS, soil sensors, weather data and mapping software to create detailed prescriptions for water applications. These prescriptions enable automated adjustments to irrigation equipment such as pivots or drip systems to vary the amount and timing of water supplied to different zones within the field. By precisely tailoring irrigation rates to match the varying water requirements of the crops and the field’s conditions, farmers can optimize resource usage, improve crop quality and yields, and achieve efficient water management in agriculture. A two-year study conducted in Minnesota shows a significant increase in irrigation water productivity using VRI compared to uniform rate irrigation. However, it’s important to note that not all fields would benefit from VRI technology. The applicability of VRI would depend on the magnitude of the spatial variation that exists in the field.

Smart irrigation technologies represent a significant step forward in the quest for sustainable and efficient agriculture. By harnessing the power of data, automation and precision, growers can optimize their water use, reduce costs and increase crop yields. As this technology continues to evolve and become more accessible, it has the potential to transform farming practices worldwide. Growers who embrace smart irrigation are not only safeguarding their livelihoods but also contributing to a more sustainable and food-secure future for all.

Vasuhda Sharma, PhD, is an assistant professor and extension irrigation specialist in the department of soil, water and climate at the University of Minnesota.



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