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MODELLING DEEP DRAINAGE RATES OF IRRIGATION STRATEGIES UNDER CROPPING SEQUENCE IN SUBHUMID, SUBTROPICAL AUSTRALIA
Author(s) -
Kodur S.,
Robinson J. B.
Publication year - 2014
Publication title -
irrigation and drainage
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.421
H-Index - 38
eISSN - 1531-0361
pISSN - 1531-0353
DOI - 10.1002/ird.1813
Subject(s) - irrigation , drainage , transpiration , cropping , environmental science , hydrology (agriculture) , water balance , soil water , water potential , crop , agronomy , forestry , geography , soil science , geology , agriculture , biology , ecology , botany , archaeology , photosynthesis , geotechnical engineering
Water availability is a major concern for irrigated vegetable cropping in the Lockyer Valley area of Australia. Soil water balance and in particular deep drainage were modelled for a representative site of this area for a range of irrigation scenarios over 12 years of cropping sequence. A scenario that refilled the soil to the drained upper limit (DUL) resulted in 530 mm yr −1 of irrigation, 673 mm yr −1 of transpiration and 84 mm yr −1 of deep drainage, whereas maintaining the soil to DUL+25% and DUL+50%, with soil moisture between DUL and saturation (75 and 50% free water respectively), resulted in similar transpiration but with increased irrigation (up to 717 mm yr −1 ) and deep drainage (up to 262 mm yr −1 ). For a given amount of available water, irrigations at fixed intervals were found to be less efficient (reduced crop transpiration) than irrigation scheduled according to a soil water deficit. This highlights the importance of moisture monitoring to optimize irrigation use efficiency. The study suggests solutions to improve irrigation efficiency by minimizing deep drainage under cropping sequences. Copyright © 2013 John Wiley & Sons, Ltd.