2nd UF Water Institute Symposium Abstract

Submitter's Name Thales Barreto
Session Name Poster Session: Optimal Use of Integrated Water Supplies 1
Category Optimal use of integrated water supplies
Poster Number 403
Author(s) Thales Barreto,  University of Flrorida
  Lincoln Zotarelli,  University of Flrorida
  Michael Dukes, University of Flrorida
  Physiological and Yield Response of Bell Pepper to Automated Soil Moisture Sensor Controlled Drip Irrigation
  The objectives of this study were to evaluate the effect of automated soil moisture sensor irrigation control on photosynthetic rate (PH) and yield of green bell pepper. The field experiment was conducted during spring 2009 in Citra, FL. The crop establishment period was characterized by application of 3 mm/day to all treatments during the first 21 days after transplanting (DAT). Irrigation treatments were set at a specific threshold of volumetric-water-content (VWC) which was allotted five irrigation windows/day and bypassed events if the VWC exceeded the established threshold. The target threshold of the treatment was 0.12, 0.08 and 0.04 m3/m3 VWC, for SMS12, SMS8 and SMS4, respectively. The reference treatment was single fixed irrigation of 5.5 mm/day event (TIME). After the onset of irrigation treatments PH was measured with LI-6200 system. At end of the season, the depth of irrigation applied to each treatment was: 21, 103, 133 and 174 mm for SMS4, SMS8, SMS12 and TIME, respectively. The average of PH during the vegetative and reproductive stages was 15.4, 16.4, 23.7 and 24.9 ┬Ámol/m2/s for the same order above. There was no difference in PH for SMS12 and TIME treatments, while SMS8 and SMS4 showed a significant reduction in PH due to the reduced irrigation depth. The marketable yield was 15.8, 24.8, 29.1 and 25.4 Mg/ha for SMS4, SMS8, SMS12 and TIME, respectively. High irrigation volume of TIME treatment resulted in appreciable water percolation captured in the lysimeters, which did not occurr in SMS treatments. The SMS12 treatment, in which the threshold was close to soil field capacity significantly reduced the amount of irrigation water, soil water percolation and nitrate leaching.