Technology Helps Growers Decide When to Stop Irrigating
Aug 5, 2019
If you stop irrigating too soon, and stress the crop before maturity, yields will be negatively impacted.
On the other hand, extra irrigations add unnecessary expenses, reduce profits and may leave the field wetter than desired when it’s time to harvest.
“The most important irrigation decisions growers make come at end of the season,” said Albert Maurin, sales and tactical marketing manager at Lindsay Corporation. “You need to make sure you’re providing enough soil water in the root zone to carry the crop to maturity and produce top yields while leaving the soil fairly dry."
So, how do you know which pass should be the last pass?
“There is not hard and fast date,” he said. “To calculate when and how much water to apply in the final stages of growth, growers need to determine the predicted crop maturity date, predicted water use by the crop to maturity, remaining available water in the soil and predicted rainfall before crop maturity.”
For growers who don’t want to rely on visual inspections and complex calculations, Maurin recommends FieldNET Advisor®– technology that takes the guesswork out of irrigation management.
“FieldNET Advisor does the work for you,” he said. “It delivers continuously updated irrigation recommendations to help growers avoid water stress throughout the season – including information that can help them use even less water at the end of the growing season.”
Using FieldNET Advisor’s unique 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 applied irrigation.
Maurin said that the red outline in the illustration 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. The char 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.
“With FieldNET Advisor, growers can be confident in their decisions, because they’re based on recognized practices for irrigation scheduling,” Maurin said. “They’ll have the information they need to decide when it’s both agronomical and economically optimal to stop irrigating.”