Protecting cotton seedlings from blowing sand with winter cover crops

"Windy days in late May can be a serious problem for Delta cotton farmers in southeast Missouri and northeast Arkansas. Young cotton plants are most vulnerable to injury from blowing sand at this time. Weather records at Clarkton, Missouri, show that the period from May 15 to 30 usually produces at least one day with maximum wind speeds greater than 35 miles per hour. The level topography in the North Mississippi River Delta region provides little resistance to wind. Many trees, which provided wind protection for young cotton plants, have been removed from field borders to allow the use of large field equipment and center pivot irrigation. Blowing sand and the constant movement of cotton leaves and stems injures cotton seedlings and young plants. Depending on the severity of the winds in a given spring, 10 to 30 percent of cotton fields without wind protection are replanted because of blowing sand. In fields with less damage, wind injury usually delays the maturity of the cotton one to two weeks. Since the region is on the northern fringe of the Cotton Belt, delays in early growth often result in yield losses. From 1992 to 1996, a study at the MU Delta Research Center showed the benefits of planting wheat cover crop in cotton row middles. Wind gauges (anemometers) placed in the rows next to cotton seedlings showed that killed wheat in row middles significantly reduced wind speed. Cotton lint yields at Portageville, Missouri, were 121 pounds per acre greater with wheat ridge-till than with conventional-till cotton. Soil temperatvure next to cotton plants was not reduced by winter wheat residue in the row middles. At first square growth stage, ridge-till cotton planted into killed wheat always averaged 1 to 3 inches taller than conventional-till cotton plants. Also light interception readings from cotton plants averaged 10 percent greater with ridge-till wheat than with conventional tillage."--First page.Authors: Gene Stevens is an associate professor of agronomy in the University of Missouri Division of Plant Sciences, Delta Research Center, Portageville. David Dunn is supervisor of the Soil Testing Laboratory at the University of Missouri Delta Research Center, Portageville.Taken from the Extension website: Reviewed Nov. 2019New 7/08/2