Automated Plant Fertigation
Stephen Kania,
Research Specialist Engineer, Agricultural and Biosystems
Engineering
A major yet independent
component of the greenhouse climate control system, the Fertigator is a
special purpose computer designed specifically to control fertilizer
injection (and acid for pH control). With the capability of
incorporating the measured value of the outside solar radiation sensor
into its decision making, in addition to signals from the electrical
conductivity (EC) and pH meters, sophisticated amendment control and
manipulation is possible. Solution electrical conductivity targets
are varied by light intensity which is computed on a 30 minute sliding
average, which can automatically modulate the electro-conductivity of the
nutrient solution for high or low sunlight intensities.
Frequency of injection cycles is controlled by summing the light received
by the plant and comparing the value to a user-set threshold.
Records of minimum, average, and maximum EC and pH levels during injection
are retained for more than the last 100 injection cycles and can be viewed
at any time. An innovative improved version of the Fertigator has
been designed and will be tested.
Cooperators: Dr. Merle
Jensen, PLS, Dr. Patricia Rorabaugh, ABE, and Dr. Gene Giacomelli,
ABE
Completed 2005 |
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