A key finding of research conducted by North Carolina State University shows that early season cotton growth rates were highest in plots that were strip tilled two weeks prior to planting.

North Carolina State University Extension Cotton Specialist Keith Edmisten.

The research, conducted in Rocky Mount and Lewiston in 2014 and 2015, also shows that yields followed very similarly to growth rates, according to North Carolina State University Extension Cotton Specialist Keith Edmisten, who discussed the research at Extension cotton meetings this year.

The sub-plots included six tillage systems, with and without a wheat cover. Tillage practices included conventional (spring bed), fall strip (flat), spring strip at planting (flat), spring strip pre-plant (flat) and full bed plus spring strip

“When yields differed, strip-tilled plots two weeks before planting had the highest yield or were not different than the highest yielding treatment,” Edmisten noted at the Rocky Mount cotton meeting.

Edmisten also discussed large plot research trials in Clayton comparing long-term tillage practices. The research looked at fall rip, fall bedding, no-till, continuous tillage, strip tillage and conventional tillage. The study was conducted in 2013, 2014 and 2015 and will continue this year, Edmisten said.

“Soil resistance was greatest in no-till plots while conventional raised beds had the least soil resistance at both planting and after harvest,” Edmisten explained. “After two full growing seasons, no-till that was ripped in the fall of 2013 had similar soil resistance measurements to conventional raised beds, suggesting that the rips effect lasted more than one growing season. In 2014, yields were highest in plots that had any form of raised beds, including raised beds in the fall of 2013.

There was no difference in yields between tillage treatments in 2015, according to Edmisten’s research in Clayton. “We will continue the study to see once we rip, how long that rip lasts and see if it is necessary to rip using equipment where we can go right back and plant at the same place where we ripped before,” Edmisten said.

“No matter what you do in terms of tillage, if you’re changing your tillage, you need to be out and looking at what effect you’re having on the root systems,” Edmisten advised.

Edmisten also discussed N.C. State research showing over 13 years, cotton responded to irrigation 54 percent of the time. The increase in yield averaged 270 pound of lint per acre due to irrigation, the study reveals.

“The increase due to irrigation averaged 463 pounds of lint per acre in seven out of the 13 years. That means a lot in terms of sustainability and reducing risks in cotton,” Edmisten said.