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Evaluation of an automatic soil moisture-based drip irrigation system for row tomatoes
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.orgCitation: Paper number 032093, 2003 ASAE Annual Meeting . (doi: 10.13031/2013.14944) @2003
Authors: R. Muñoz-Carpena, H. Bryan, W. Klassen and T.T. Dispenza, Michael D. Dukes
Keywords: Irrigation, vegetable crops, water conservation, soil moisture monitoring
A low-volume/high frequency (LVHF) soil moisture-based drip irrigation system was tested on a commercial tomato farm in South Florida. Seven irrigation treatments were compared. In the first six treatments the system was pressurized by means of an electrical pump and a pressure tank, and controlled by an irrigation timer (controller) set to irrigate 5 times per day. The last treatment consisted on the farms standard commercial practice where a portable pump was used on a twice a week manual irrigation schedule. Four of the six LVHF treatments resulted from interfacing, in a closed control loop with the irrigation controller, two types of soil moisture sensors (switching tensiometers and granular matrix sensors) set at two moisture points (wet: 10 cbar, optimal:15 cbar), The other two LVHF resulted from the same system with no sensors with two timer schedules, one to supply 100% of the maximum recommended crop water needs and the other to supply 150% of those needs. Results from the six LVHF treatments show that tomato yields were not different than that of the commercial field while conserving water. Switching tensiometers at 15 cbar set point performed the best (up to 73% reduction in water use when compared to commercial farm, 50% with respect to the 100% recommended crop water needs treatment). Routine maintenance was critical for reliable operation of the switching tensiometers. Granular matrix sensors behaved erratically and did not improve water savings compared to the 100% recommended crop water needs treatment.(Download PDF) (Export to EndNotes)