Tomato and Pepper Root Distribution Associated to Different Irrigation Management and N-Leaching Under Plastic Mulch Conditions.
Lincoln Zotarelli, Michael Dukes, Johannes Scholberg, Jason Icerman, Kristen Le Femminella, and Rafael Munoz-Carpena. University of Florida, Agricultural & Biol. Engineering Dept., 234 Frazier Rogers Hall, PO Box 110570, Gainesville, FL 32611-0570
The aim of this study was to evaluate the pepper and tomato spatial distribution and density of roots as function of soil water availability and soil nitrate movement. Pepper and tomato were transplanted in spring 2006 and three irrigation scheduling methods were evaluated for each crop. Soil moisture sensor control system treatments irrigated depending on the volumetric soil water content readings up to a maximum of five irrigation events could occur per day totaling 2 hr, and the amount of application time equivalent to the once a day (FT) fixed time treatment. For tomato, the effect of subsurface drip irrigation was also evaluated. Leachate volumes were measured by drainage lysimeters. There was a higher concentration of roots closer to the irrigation and fertigation drip lines independent of the irrigation treatment or crop. In general, at the beginning of reproductive phase about 70-75% of the root system was distributed in 0-15 cm depth layer and about 15-20% of the roots were found in the 15-30 cm depth layer. In the middle of the reproductive phase 68% and 22% of the root system were found at 0-15 and 15-30 cm depth layer, respectively. For both crops, about 90% of the root system was located at top 30 cm of soil for both crops. The root distribution in the soil profile appears to be driven by soil moisture and nutrient availability. There was higher concentration of roots closer to the irrigation and fertigation drip lines independent of the irrigation treatment.