More Farmers Using Precision Agriculture: January 1999 Soybeans Today

Soybeans Today January 1999

More Farmers Using Precision Agriculture

By Rich Maples

Satellite beams and computer mapping programs. It's not science fiction. They're tools of modern farming, of precision agriculture.

Mike Daniels, an environmental management specialist for the Cooperative Extension Service, University of Arkansas, says farmers are using the Global Positioning System (GPS) and Geographic Information Systems (GIS) to pinpoint differences within fields.

"GIS and GPS are used with yield monitors to produce maps that depict yield differences for areas as small as one-hundredth of an acre," says Daniels. "The yield monitor mounted on the combine determines the yield on the go as the GPS marks the location. All this information is fed into the GIS software, which creates a yield map."

Once differences in yield are mapped, the grower can determine the cause. Southeast Arkansas farmers John Freeman and Kim Ellington use the GPS and GIS technology to map phosphorus and potassium levels of fields in the grower-checkoff-funded Soybean Research Verification Program (SRVP).

Freeman, who farms in Lincoln County, divided his 80-acre SRVP field in half. On one-half, soil and nematode samples were collected on a grid, at 16 precise points 2.5 acres apart. The other 40 acres were sampled conventionally.

He says he couldn't tell much difference in the 40 acres that were fertilized at one rate and the 40 acres that were fertilized at a variable rate.

Chicot County farmer Kim Ellington, using his own GPS equipment, grid sampled his 70-acre SRVP field in 1997 and 1998. Soil and nematode samples were collected at 32 grid points, 2.5 acres apart. The field was limed and fertilized on the grid.

Stand counts were taken at the grid points and tissue samples were collected when plants reached the R2 stage, at the beginning of reproduction.

Unlike Freeman's trial field, which was fairly uniform in soil type, Ellington's trial field was silt loam on one end and heavy clay on the other.

No variable rate applicator was available when it was time to fertilize, but Ellington still used the grid map to fertilize and lime the field with a buggy.

Ellington says soil sampling on the grid helped him increase his average yield on the 70-acre field from 32.5 bushels per acre in 1996 to 55 bushels per acre in 1997. "The improvement was in fertility, mainly lime."

Soybeans Today January 1999
Table of Contents

For additional information about any board-related activity contact:

Arkansas Soybean Promotion Board
ATTN: Brandy Carroll
P.O. Box 31
Little Rock, AR 72203-0031
Phone: 501-228-1268

Web Services by Aristotle Web Design.
Privacy Policy