reduction in irrigated crop production: Effects of techniques, irrigation strategies and mulching practices Chukalla, A.D.; Krol, M. S.; Hoekstra, A. Y. Twente Water Center, University of Twente Contact: [email protected] Introduction Results Water footprint (WF) reduction in irrigated crop production is essential given the increasing Effect of irrigation techniques on Y and ET Water footprint for rainfed and irrigated 30 potato in Badajoz - Spain production, tomato in Badajoz - Spain completion over fresh water. Our study explores measures that affect the -water- 28 26 Green WF Blue WF Yield Irrigation 180 0 balance and plant-growth, and thus influence yield (Y) and/or (ET) and 24 9.2t/ha 17t/ha

22 160 100 123t/ha

Yield (t/ha) Yield 20 138t/ha

therefore the WF of a crop. 140 200

250 300 350 400 450 ) / ton) / Evapotranspiration (mm) 3 120 300

Evapotranspiration 400 (mm 100 Rainfall Irrigation Effect of mulching on Y and ET 500 potato in Badajoz - Spain 80 Runoff Runoff ) 30 600

60 Irrigation 25 700 40 Blue 800 20 (m footprint Water Green Blue Partitioning of soil water into: 20 Yield (t/ha Yield 900 soil moisture (1) green soil moisture and soil moisture soil moisture 15 0 1000 from irrigation (2) blue soil moisture 200 250 300 350 400 450 from Rainfed Supplementary Deficit Full Evapotranspiration (mm) irrigation irrigation irrigation capillary rise Reduction in water footprint The change in Water footprint (∆WF) was compared to a reference of Furrow technique with non - Capillary rise water stress irrigation scheduling - without mulching. SSD = Subsurface drip 5

Deep percolation 0 -5 Method -10 -15 Measures Modelling Effects -20 -25 Management options WF (%) to Change -30 1. Four irrigation techniques: Furrow, Sprinkler, Drip and -35 Subsurface drip (SSD); Green and TECHNIQUE Drip:SSD Furrow:Drip:SSD Furrow:Drip:SSD:Drip/SSD Furrow:Drip:SSD:Drip/SSD STRATEGY Full Irrigation Deficit Irrigation Full Irrigation Full Irrigation AquaCrop MULCHING No mulching No mulching Organic:Organic:Organic:Synthetic Organic:Organic:Organic:Synthetic 2. Three irrigation strategies: full irrigation, deficit Blue WF of Measures WF accounting irrigation & supplementary irrigation; + rainfed; growing crops Conclusion 3. Three mulching practices: without, organic & synthetic The reduction in water footprint compared to the reference (the furrow technique with mulching. non-water stress scheduling and without mulching) is: (1) 12% for Drip or Subsurface Cases drip, (2) 10% for organic mulching, (3) 20% for Drip and subsurface drip with organic Two environments (arid in Israel & semi-arid in Spain), three crops (, potato & tomato), three (loam, sandy loam, silty clay loam), three types of years (wet, normal & dry) mulching, and (4) 28% for Drip and subsurface drip with synthetic mulching. Acknowledgment This research was conducted as part of the EU-FP7-funded project FIGARO