The objective of this work was to establish comparisons among characteristics and dimensions of wetted volumes under surface and subsurface drippers at the end of an irrigation cycle and to evaluate mathematical models for predicting dimensions of these wetted volumes. The study was carried out in a Yellow-Red Podzol in Fortaleza-CE. Water volume of 4.3 x 10-3 m³ (4.33 L) was applied by drippers with flow rate of 7.22 x 10-7 m³ s-1 (2.6 L h-1) during the studied irrigation cycles. Soil water dynamics monitoring was accomplished by tensiometers. Measurements of soil-water potential were done before the irrigation event and during two irrigation cycles. At the end of the two irrigation cycles the water content that was available in the wetted volume under the buried dripper was 44 to 29% larger than the water content that was available in the wetted volume under the surface dripper. The Schwartzmass & Zur model resulted in a better approximation to the experimental data.
Sub irrigation; wet bulb; models
