Variable rate system helps protect cotton crops and the environment

By Tom Lollis

NematicideA variable-rate application system, developed by Clemson scientists, allows cotton farmers to apply fewer chemicals to control nematodes, thereby saving money and protecting water quality.

Nematodes are the most numerous multicellular animals on earth. A handful of soil will contain thousands of the microscopic worms, many of them parasites of insects, plants or animals. The site-specific nematicide placement project is a two-year cooperative effort with the University of Arkansas, led by Ahmad Khalilian, agricultural engineer at Clemson’s Edisto Research and Education Center in Blackville.

Clemson scientists divided each field into three zones, applying a nematicide conventionally and at variable rates based on global positioning system mapping of soil types. The satellite maps show the exact locations of light, sandy soils that nematodes prefer. Treatment is applied to these areas but not to heavier, organic soils that are less likely to contain nematodes.

Researchers expect farmers to reduce their use of nematicides by as much as one-third by using the variable rate system. This will reduce production costs and protect groundwater quality.

For information: Ahmad Khalilian, 803-284-3343, ext. 230,