Does partial root-zone drying improve irrigation water productivity in the field? A meta-analysis
Date
2009
Authors
Sadras, V.
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Journal Title
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Volume Title
Type:
Journal article
Citation
Irrigation Science, 2009; 27(3):183-190
Statement of Responsibility
V. O. Sadras
Conference Name
Abstract
Partial root-zone drying improves irrigation water productivity (IWP, yield per unit applied irrigation water) with respect to controls receiving substantially more water, but similar gains are often achieved with conventional deficit irrigation. This paper presents a meta-analysis of IWP for a broad range of horticultural crops and environments. Two comparisons were preformed: (a) crops managed with either partial root-zone drying or conventional deficit irrigation against controls receiving substantially more water than the two water-saving techniques, (b) crops managed with partial root-zone drying and their counterparts with conventional irrigation where both received similar amounts of irrigation. In relation to controls receiving substantially more water, conventional deficit irrigation increased IWP by an average 76% and partial root-zone drying by 82%; the gains from both water-saving methods were statistically undistinguishable. Yield per unit applied irrigation water of crops under partial root-zone drying was significantly (P = 0.007) but modestly (5%) higher than in their counterparts with conventional irrigation where both received similar amounts of irrigation. In 80% of cases the difference in IWP between the two methods was in the ±20% range. Considering the cost and management complexity of implementing partial root-zone drying, it is critical to identify the rare conditions where this method could be economically justified.