Use of Tensiometers for Computer Control of Irrigation for Container-grown Plants PDF Download

Author: Saadettin Yildirim
Publisher:
ISBN:
Category :
Languages : en
Pages : 118

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Book Description
Abstract: A Q-COM computer-controlled system along with tensiometers was used to monitor and control irrigation for container-grown, mini-roses (Rosa hybrida 'Meidanclar' and 'Meirutral'). Three different Soil Moisture Tension (SMT) treatments: low tension (3 to 6 kPa), medium tension (9 to 12 kPa), and high tension (15 to 18 kPa) and a Timer Controlled (TC) treatment were chosen and compared. The tensiometers used in this experiment were able to effectively measure soil moisture tension in the root zone of the potted plants. The computer-controlled, irrigation system for container-grown plants was also able to continuously monitor the soil moisture level, call for irrigation in time when the soil required water, and stop the irrigation when an adequate amount was applied. The control system was not always successful at keeping the soil moisture at a pre-set tension range. Control gradually became more erratic and difficult as the tension level increased. The best SMT treatment for control capability was the low tension (3 to 6 kPa) treatment. Stable control of soil moisture tension was not successfully achieved for high SMT (15 to 18 kPa) treatments. As the SMT increased, the quantity of water supplied decreased. Water used was higher for the TC based irrigation treatment than for any of the three SMT based treatments. The mini roses were grown with substantially less water by using SMT based irrigation treatments than with timer control. As time elapsed and the plants grew, the rate of water applied increased for SMT based treatments. Water use rate increased linearly with respect to time for all three SMT treatments during the first 30 days while the rates were nearly constant during the following 23 days. Tensiometers with various inside air volumes were used to sense soil tension. There were no differences between the tensiometers in terms of stability. However, increasing air volume inside the tensiometer probe reduced tensiometer accuracy.