Cotton Sidedress Time is Here
Posted by romeethredge on June 30, 2011
Time to sidedress cotton to get top yields is here on lots of our cotton.
Alex and Kayleigh Johnson are spreading sidedress fertilizer on this squaring cotton in southern Seminole County this week. Here below they’re checking the spinners and the gates on the fertilizer spreader.
Here’s some comments from Dr Glen Harris, UGA Extension Crop Scientist. The total N rate should always be applied in split applications. Apply 1/4 to 1/3 of the recommended N at planting and the remainder at sidedress. The preplant or at planting Napplication is critical for getting the crop off to a good start and ensuring adequate N nutritionprior to side-dressing.
Sidedress N between first square and first bloom depending on growth and color (toward first square if slow growing and pale green, toward first bloom if rapid growth and dark green). A portion of the sidedress N can also be applied as foliar treatments or through irrigation systems.
There are a number of nitrogen fertilizer materials that can be used on cotton including UAN solutions, ammonium nitrate and urea. UAN solutions are made up of urea and ammonium nitrate and often contain sulfur (e.g. 28-0-0-5). Ammonium nitrate is losing favor as a sidedres sN source for cotton due to higher cost and burn potential. Urea is being considered as an alternative to ammonium nitrate but is known to be prone to volatilization losses. Volatilization losses can be minimized however by irrigating after a urea application or by use of a urease inhibitor such as Agrotain. Feed grade urea is still the product of choice for foliar N applicationslater in the growing season. Controlled release nitrogen foliar products are also available but usually contain potassium and boron and are less concentrated in N.