INFILTRATION-RATE MEASUREMENTS IN ARID SOILS WITH SURFACE CRUST

Citation
Mi. Alqinna et Am. Abuawwad, INFILTRATION-RATE MEASUREMENTS IN ARID SOILS WITH SURFACE CRUST, Irrigation science, 18(2), 1998, pp. 83-89
Citations number
16
Categorie Soggetti
Water Resources",Agriculture
Journal title
ISSN journal
03427188
Volume
18
Issue
2
Year of publication
1998
Pages
83 - 89
Database
ISI
SICI code
0342-7188(1998)18:2<83:IMIASW>2.0.ZU;2-D
Abstract
The effects of infiltrometer type and water application rate on infilt ration were studied for a crust-forming soil at the University of Jord an Research Station near Al-Muwaqqar village. The total amount of wate r applied in all cases was 38 mm. The highest infiltration rate values occurred in basin infiltrometers followed by sprinkler and furrow inf iltrometers. The infiltration rate at the end of water application dec reased significantly by 41-57% with decreasing application rate from 2 8.4 to 6.2 mm/h regardless of infiltrometer type. Increasing the initi al soil oar moisture content decreased the infiltration rate by about 4-11% in all infiltrometer types and application rates. In the basin i nfiltrometer, lateral water movement occurred all around the basin bor ders, thus increasing the measured basic infiltration rate. In the fur row infiltrometer, the for formation of a sedimentary crust on the fur row bottom reduced the basic water infiltration rate to 3.6 mm/h. The wetted zone formed with the sprinkler infiltrometer reduced lateral wa ter movement, and the measured basic infiltration rate was close to th e basic infiltration rate measured by the double-ring infiltrometer. T he measurements were used to establish infiltration rate curves and eq uations. In a second experiment, the Stirk correction significantly re duced the water lateral divergence factor by 27.1% in single-ring infi ltrometers. The Stirk correction factor was different in single- and d ouble-ring infiltrometers. Thus, the basic infiltration rate was 4.8 a nd 3.5 mm/h using the single and the double infiltrometers, respective ly, while the corresponding correction factors were 0.67 and 0.91, res pectively. The corrected infiltration rate was only 3.2 mm/h, which co nfirms the tendency of these crusted soils to generate huge runoff at even small application rates.