When Should You Stop Irrigating? - Part Two

In part one of our series about when to stop irrigating for the season, Tim Wilson, irrigation engineering manager at Lindsay Corporation, explained why it’s a critical decision.

“If you stop irrigating too soon and stress the crop before it reaches maturity, yields will be impacted,” he said. “On the other hand, watering longer than you really need to adds unnecessary expenses, reduces profits and can leave the field wetter than desired come harvest time.”

Wilson added that with FieldNET Advisor™, growers no longer have to rely exclusively on visual inspections of their fields or complex calculations when trying to decide when to make the last pass of the season.

We asked Kurtis Charling, a technology professional at Lindsay, to explain how FieldNET Advisor provides growers with the information they need to determine when it’s economically optimal to stop irrigation. 

What kind of data does FieldNET Advisor compile to help growers determine when to stop irrigating?

FieldNET Advisor compiles a massive amount of data, including field-specific, hyper-local historic, current and forecasted weather data, to calculate the hourly reference evapotranspiration throughout the growing season. It also pulls in the actual and forecasted rainfall and past irrigation records. It combines this data with the field’s crop zones and soil types to track crop development, hourly water usage and the current available water in the root zone. It then forecasts these outputs through crop maturity to generate a daily recommended irrigation schedule. As the crop approaches maturity, the irrigation recommendations generated by FieldNET Advisor automatically use proven irrigation management concepts to fully mine the soil’s existing water and reduce or cease irrigation applications as soon as they are no longer necessary to avoid yield loss.

When using FieldNET Advisor, how will growers know when it’s time to stop irrigating?

FieldNET Advisor’s daily irrigation recommendations are optimized to help the grower avoid crop water stress through the season. For growers wanting to optimize the financial return of their water application even further, FieldNET Advisor provides additional information that can help growers use even less water at the end of the growing season. Using FieldNET Advisor’s unique, patent-pending forecasted yield loss (see red highlighted yield loss section in the image above), growers have the data they need to decide when it’s economically optimal to stop irrigating. This forecasted yield loss is an estimate of the percentage of the crop’s yield potential that will be lost if no additional irrigation is applied through the remainder of the season. With this information, a grower may decide to reduce the final irrigation amount or stop irrigating altogether to let the crop further deplete the soil water – particularly if the yield loss is minimal or if the value of the projected yield loss, without additional irrigation, is less than the cost of applying that irrigation.

The red outline above highlights the graphical view of FieldNET Advisor’s projected irrigation schedule, which growers can use to help confirm their decision to reduce or suspend irrigations at the end of the season. This chart displays the season-to-date soil water depletion and irrigation history. It also shows the forecasted soil water depletion and irrigation recommendations through the remainder of the growing season based on the field-specific hourly weather forecast out 15 days in the future and field-specific historical norms beyond the 15 day forecast.

How confident should growers be with FieldNET Advisor’s recommendations?

They should be extremely confident, knowing their decisions are based on recognized best practices for irrigation scheduling. FieldNET Advisor utilizes more than 40 years of proven crop and irrigation research that has been thoroughly tested and validated to provide the data growers need to make decisions related to stopping or reducing irrigation application for the remainder of the growing season.

For more information about FieldNET Advisor, talk to your local Zimmatic dealer or visit