PRINCETON, Ky. — The use of irrigation in farming in Kentucky has historically been limited.

In 1999, University of Kentucky (UK) extension soils specialist Lloyd Murdock published a report on the use of irrigation in the state. The first reason for limited irrigation, Murdock said, is there is typically adequate rainfall throughout the state to produce a good crop. The second reason he gave is that reliable water sources needed for irrigation are not available in many places in Kentucky.

More recently, a farmer in Adairville made news after he installed a center point irrigation system in 2007 to deal with the drought that had just devastated his corn crop. With his new system, the farmer felt sure he could increase the plant population in his irrigated fields. Consequently, he won a corn yield contest in 2008 with 305.9 bushels per acre.

The next widespread drought in Kentucky came in 2012. After the weather had devastated many a crop, a team of graduate students from UK collaborated on a research project to study the potential for irrigation in Daviess and Henderson counties.

Thanks to adequate water resources such as the Ohio River and Green River tributaries, and to the good moist soil in these locations, irrigation was already being used widely there. So, working with UK grains specialist Chad Lee, the students surveyed several area producers about irrigation equipment and the agronomic and management practices they employed.

The following August, the university’s College of Agriculture presented a special irrigation forum for producers in Princeton. A panel of experts, including Murdock and Lee, were there to answer questions about irrigation, water use and yield. The graduate pair’s research findings were discussed at the meeting, among other items.

Later, Lee said, "In Kentucky we look at irrigation as something that is supplemental. You may need just a few inches of water to carry you through the dry times. And many years there is enough rainfall that there is no need to run the irrigation equipment.

"We are doing irrigation research and looking at how we can push plant populations higher, and whether or not we will need to adjust the nitrogen rates in order to get maximum yield with irrigation."

He noted that for high plant populations and high yield numbers, irrigation is a necessity because the high-population crops are more sensitive to water stress. "We are testing what the yield potential is going to be when populations are high and we have got (enough) water. In our studies we are going up to 60,000."

In order to get 60,000 plants per acre, he said it is necessary to plant corn in 15-inch rows. Spacing corn like this can sometimes be problematic; for instance, he said walking in 15-inch corn is less comfortable than walking in 30-inch rows. Also, it can be difficult to move equipment that is set up for 30-inch rows around in the field in season.