UT Sensors & Controls Lab -- Project Reports


	Tennessee Rate Application Control System (TRACS) for Automation of Field-Scale Agronomic Research

	Agronomic research involves applying treatments to experimental units (plots), measuring results, and interpreting these results using statistical analysis techniques. Plot layout and treatment application typically require large labor investments, which often constrain the number of treatments and/or replications that can be included in an experiment. Geographical information systems, global positioning systems (GPS), and variable-rate application controllers are technologies with potential to reduce labor requirements associated with agronomic field studies. However, commercially-available systems implementing these technologies are not tailored toward agronomic research. University of Tennessee Sensors and Controls Lab personnel initiated an effort to develop an automated plot layout and treatment application system in 1998. The product of this effort is the Tennessee Rate Application Control System (TRACS). TRACS consists of two sub-systems - a management system and a field system. The management system is a PC-based software package for designing experimental layouts. Using this software, a user enters the following information when planning an experiment: (1) field boundary and row orientation information, (2) type and number of treatments to be applied, and (3) the desired number of replications. Plot locations and treatments are automatically generated to form a completely randomized design. Resulting application maps are transferred to the field system. The field system includes the following components: a GPS receiver, a graphical user interface, a rate control module, and an operator guidance light-bar. The user interface provides operator access to stored application maps, and continuously displays machine position in relation to the selected map. The rate control module varies application rate as the machine travels through plots. It uses real-time position information from the GPS receiver in conjunction with treatment information from the application map to control the application rate. The operator guidance light-bar provides feedback to assist the operator in vehicle navigation. TRACS performance was evaluated during 2000. Management system software was used to lay out several experiments, and resulting application maps were downloaded to the field system. Field system testing included multiple operators, who each completed a survey following the test. Comments were generally positive, and the system was deemed appropriate. Several improvements are possible, and should be pursued in the future.


	Publications:
		Rye, S.W. 2000. Variable application rate control system for field scale research. 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