Non-Intrusive Corn Stalk Sensor for Plant Population Mapping

On-going work in the area of site-specific crop management suggests that many of the factors that affect crop production vary significantly within fields.  When one or more of these factors can be identified and quantified site-specifically, opportunities exist to increase production efficiency using advanced technologies.  For several years, corn producers have been interested in variable rate seeding as one way in which to improve production efficiency.   Many believe that zones within a field that have higher yield potential should be seeded more heavily than zones with lower yield potential.

While this management concept has merit, it also raises many questions.  Many of these questions involve corn plant germination and mortality rates, as well as how germination and mortality rates vary within fields.  Farmers and researchers trying to address these issues need a system that is capable of site-specifically quantifying corn plant population at harvest.

Sensors and Controls Lab staff members are working on a solution.  A combine-mounted sensor that counts corn plants as they are pulled into the header has been prototyped and tested under laboratory and field conditions.  The sensor consists of an array of electrodes arranged such that the electrical capacitance of the array changes when corn stalks pass by the sensor.  This change in capacitance is detected and used to count stalks.

While the prototype sensor shows promise, the current design does not provide adequate sensitivity when sensing very dry corn stalks (<10% m.c.).  This limitation is being investigated and may be overcome with improved electrode geometry/placement and electronics.  Additional engineering will be required to transform the laboratory prototype into a robust product ready for commercialization.

The Sensors and Controls Laboratory is committed to developing new technology to aid agricultural research and production.

Publications:

Webb, N.A.  2001.  Real-time system for determining corn plant population in-situ at harvest time.  M.S. thesis.  The University of Tennessee, Knoxville, Tenn.

For more information about this project, please contact:

John Wilkerson, Ph.D.
The University of Tennessee

2506 E. J. Chapman Drive
Knoxville, TN  37996-4531
PHONE:  (865) 974-7266
wilkerj@utk.edu