Agronomic Services — News Release
FOR IMMEDIATE RELEASE
TUESDAY, MAY 20, 2003
Contact: Kent Messick
Agronomic Division Field Services section chief
Look out for sulfur deficiency problems in plants
by Kent Yarborough & Tim Hall, NCDA&CS regional agronomists
PLYMOUTH — Frequent, heavy rains over the past six months have caused sulfur deficiency in many crops. Winter wheat, cabbage, and other leafy greens began showing these problems in March and April, and cases are now turning up in corn. Low sulfur is also likely to show up in the cotton crop now being planted and possibly in tobacco, bermuda grass hayfields, summer produce, and in some home lawns and gardens.
"Seventy-two percent of the corn tissue samples that we've analyzed this season are low to deficient in sulfur," said Dr. Bobby Walls of the N.C. Department of Agriculture and Consumer Services' plant/waste/solution lab.
Crops need sulfur. A 120-bushel corn crop will use approximately 20 pounds of sulfur per acre; 70-bushel wheat, 18 pounds per acre; two-bale cotton, 24 pounds per acre; 4,000-pound peanuts, 21 pounds per acre; and 3,000-pound tobacco, 19 pounds per acre. Crops take up anywhere from 8 to 54 pounds per acre of sulfur.
In sandy, coarse-textured soils, sulfur moves readily down into the soil. During excessive rainfall, sulfur may be washed out of the root zone. Soils that contain clay, however, can retain sulfur. Sulfur tends to accumulate in the top few inches of clay layers.
Before you can correct a nutrient problem, you have to be sure of the problem. Sulfur deficiency is easily confused with nitrogen deficiency. With nitrogen deficiency, older leaves are yellow to light-green. With sulfur deficiency, newer leaves show these symptoms more than older leaves.
If your crop looks pale or yellow, consider submitting a plant tissue sample and a matching diagnostic soil sample for analysis. Ideally, areas that look healthy should also be sampled for comparison. Send samples along with completed information forms to the NCDA&CS Agronomic Division, Plant/Waste/Solution Section, 4300 Reedy Creek Road, Raleigh, NC 27607. Mark the package as “PROBLEM SAMPLES” to identify these samples as priority.
Growers making decisions about sidedress fertilizers should review their most recent NCDA&CS soil test report with particular attention to the sulfur-index value (S-I) for each field. If the S-I value is 25 or less, an application of 20 to 25 pounds per acre of sulfur is recommended. However, if the field has sandy soil and there has been a lot of rain since the soil test was done, a sulfur application may be needed even if S-I values are greater than 25.
For assistance with nutrient-related crop problems, contact your local NCDA&CS regional agronomist or your county Cooperative Extension agent. To identify and contact the regional agronomist assigned to your area, visit the Web page www.ncagr.com/agronomi/rahome.htm or call J. Kent Messick at (919) 733-2655.
August 1, 2007