Researchers are hoping a new, on-farm study using soil moisture sensors will help transform the art of irrigation timing to the science of irrigation timing.

A panel at Cotton Incorporated’s Crop Management Seminar in Tunica, Miss., discussed the results of the study recently, as well as other irrigation research and their thoughts on why irrigation efficiency is critical to producers.

The study took place on the farm of Chris Bush, a third generation row crop farmer from Greenwood, Miss., who produces cotton, corn and soybeans on about 12,000 acres. The farm is about 95 percent irrigated, mostly by furrow. The study evaluated Decagon and WaterMark soil moisture sensors equipped with wireless communication, for their ability to schedule irrigations.

(For a video interview with Chris Bush, see New moisture monitoring programs could reduce irrigation costs).

“We all know that timing is critical,” Bush said. “It is easy to manage water when the weather is hot and dry, because you can get in a rotation. The challenge for me is knowing when to resume watering after a rain, and this is when the sensors really help.”

The sensors were placed at 8 inches, 16 inches and 24 inches deep, in an approximately 100-acre field divided into quadrants. They provided season-long information to Bush and researchers for the project, which was funded by Cotton Incorporated.

This season’s results were surprising, according to Mississippi Extension Cotton Specialist Darrin Dodds, who helped with the study.

“It’s interesting that the quadrants we watered three times averaged about 1,400 pounds. The ones we watered twice averaged 1,500 pounds. We watered (the higher yielding quadrants) a little later, which is a little bit contradictory to the information coming out of Arkansas, which indicates you should water beginning about a week prior to bloom. Certainly rainfall plays into this. And we need to come back and tie some rainfall data into the results.”

Dodds said irrigation results can often be mixed, depending on factors like rainfall, temperature, soil type and even variety. But irrigation methods, and research, can always be fine-tuned for better results. “One of the biggest questions that comes to mind are the intervals between watering,” Dodds said. “If we stretch those out and put a little stress on the crop before we give it some water, what is it going to do to our yields? Where is that edge? We want to push that crop to make the best crop at the least amount of cost.”