Last year, a number of cotton, corn and soybean producers irrigated their crops for the first time due to the extensive drought in the region. This year, ample rain fell and irrigation was used sparingly, according to Dave Verbree, a speaker at the UT Cotton Tour. Verbree says he’s been told west Tennessee hasn’t had a normal year since he came to the West Tennessee Research and Education Center several years ago.
Verbree asked for a show of hands of how many farmers irrigated cotton in 2013. Only four or five farmers in the audience of 50 or 60 responded. That was understandable, he said, given the high amounts of rainfall growers received until fairly late in the growing season when it turned off drier than “normal.”
Agronomists at the WTREC in Jackson are conducting research at the station and at on-farm locations in west Tennessee to determine the best management practices for applications of nitrogen and water. “We find that irrigation nitrogen research is pretty much inseparable,” says Verbree. “As we pump a lot of irrigation in we start getting problems with rank growth which is the same case with a lot of nitrogen applications.”
Verbree’s studies involve both drip irrigation and center pivot systems, the two predominant forms of irrigation in west Tennessee. In general, few farmers use furrow irrigation on the rolling hills that dominate the landscape in the western portion of the state. More and more center pivots have been installed to offset the lack of moisture at key growing periods.
The Penn State and Texas A&M University graduate included a table in his presentation that illustrated peak water usage for the cotton plant. The period frequently occurs in late July and August when the cotton plant typically undergoes its greatest moisture stress. Researchers recommend growers stop irrigation at first open boll to allow the cotton plant to begin drying down and to reduce the potential for regrowth following defoliation.