Applying fertilizer as efficiently as possible has always made sense. With current record high prices for nitrogen and other nutrients, however, efficiency has become of paramount concern.

Plant biomass sensors currently available give farmers the option of delaying some fertility decisions until later in the season and then applying only what’s necessary to achieve reasonable yield goals.

“A Green Seeker sensor goes over the plants and determines biomass and greenness,” says Kevin Bronson, soil fertility researcher at the Texas A&M Research and Extension Center in Lubbock.

“Farmers can determine in-season nutrient needs,” Bronson said during a recent West Texas Agricultural Chemicals conference in Lubbock.

He said producers may save nitrogen and phosphorus expenses with variable rate application following sensor readings. “Soil sampling is still a key,” he said. Farmers use a “zone approach,” based on plant vigor determined by the sensor, to schedule fertilization.

Green Seeker technology also offers cotton farmers opportunities to measure biomass and plant vigor to schedule plant growth regulator and harvest aid applications. “Cotton growers can use the technology to determine zones with larger plants. “They can apply Pix to areas with large plants and not to areas with less vigorous cotton.”

Texas Extension Cotton Specialist Randy Boman says current high fertilizer prices require growers “to do a better job of sampling and applying nutrients efficiently. They need to identify specific nutrient needs.”

Sensor technology, he said, allows them to do that without sacrificing yield potential.

email: rsmith@farmpress.com