Team

1. Regional Knowledge Exchange on Decision-support Tools and Models to Project Improved Strategies for Integrated Management of Land, Water and Livelihoods 22-27 September, 2013, Djerba, Tunisia Strategic Approaches to Integrated Management of Land, Water and Livelihoods along an Aridity Gradient: Southern Tunisia site

2. Team

3. Study sites in Tunisia S1 S1 (North): Tunis (semi arid) S2 (Centre): Sidi Bouzid/Kasserine (semi arid) S3 (South) : Medenine/Tataouine (arid) S2 S3

4. Wadi Hallouf/Oum Zessar watersheds, Medenine • Transect stretching from Plateau of Dhahar to the Gulf of Gabès (Mediterranean sea): 3 main basins: wadis of Hallouf, Oum Oum Zessar, Oum Ettamr). • Area: around 1500 km2. • Rainfall ranges between 160 mm (east, plain of Jeffara) , 200 mm (central part, mountain of Beli Khedache) and less than 100 mm (west, plateau of Dhahar). • Land use: East: olives, small scale irrigation; Central: fruit trees behind water harvesting structures; West: rangelands. • Population: around 50000 inhabitants

6. Modelling Olive groves vulnerability to cc

7. climatic data: Baseline period, until 2030 and until 2090 Soilmap Land use map Images Landsat 5 and 7 Geométric and atmospheric correction collecting data Treatement NDVI HidroMORE Conceptuel Model 9

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9. Gabion check dams efficiency

12. Water management in the irrigated area

13. Actions 1- Evaluation of on-farm irrigation scheduling of drip irrigated vegetable crops under arid conditions of Tunisia 2-Deficit irrigation of orchards : case study of citrus trees Location - Bedoui & Megarine in the arid part (R: 150 mm & ETo: 1500 mm)

14. Pilot site: Evaluation of on-farm irrigation scheduling of drip irrigated vegetable crops under arid conditions of Tunisia. - Water source: private shallow well having an ECi of about 5.8 dS/m, flow rate ranging between 3-4 l/s and a depth less than 35 m - Soil: Sandy soil texture (Clay: 6.77%, Loam: 12.68% & Sand: 80.55%) having low organic manure (<0.8%) - Vegetable crops: potato, carrot, green bean and pepper - Irrigation system: Drip irrigation method 

15. Irrigation scheduling methods Two irrigation treatments based on the use SWB to estimate irrigation amounts and timing were compared to traditional farmer practice. Field monitoring • Soil salinity and water content • Ground canopy cover, stomatal conductance • Yield and its components at physiological maturity • Water supplies (I+R) (using water meter and rain gauge) • Water productivity (WP) WP (kg/m3) = Yield (kg/ha) / irrigation water (m3/ha)

16. Results First year of experiment Data collected on Potato, carrot & green bean, Pepper experiment is still in progress

21. Pilot site Megarine: • Irrigated field (55ha) with relatively fresh water (1-1.5 g/l) from a tube well. • Pilot site serve testing technical itinerary for fruit trees • Field experiments on improved water productivity by deficit irrigation and irrigation scheduling: Implications for saving water in citrus orchards • Experiments in a drip irrigated citrus orchards are actually launched in the zone of Megarine, Médenine. (12 years-old ‘Meski Maltaise trees grafted on Bigaradier with tree spacing of 7x6 m) • Four drip emitters per tree (4 l/h) connected to a double drip line, two per side of the tree, are used in the experiment

22. Pilot site: Improved water productivity by deficit irrigation and irrigation scheduling: Implications for saving water in citrus orchards

23. Irrigation treatments - Control treatment (FI-100) irrigated at 100% of - The DI treatments irrigtaed at 75 and 50% of ET (DI-75, DI-50) - FM irrigated according to farmer irrigation practice FM, DI & FI implemented during the active period of citrus corresponding to different phenological stages (flowering and initial fruit set, fruit growth, and maturity) and post-harvest • For citrus experiment • Irrigation strategies will be evaluated according to their impact on: • amount of irrigation water saving • vegetative growth (diameter fruits) • stomatal conductance • yield, fruit size, total soluble solids (°Brix) • water productivity • - soil salinity

24. MPDELLING Climate change impact and adaptation strategy assessment on crop production

25. Selected crop : potato • Model selection: Aqacrop • - Meteorological data • Médenine station • Climate scenarios • Minimum and maximum temperature and rainfall projections will be used as input for t the AquaCrop model and to estimate the future ETo using the FAO tool EToCalculator. - Modelling the impact of climate change on crop yield - Calibration and Validation of AquaCrop for Potato • Field experiments (2001-2004) in Médenine region • Calibration and validation of the model • Collection of weather data, soil characteristics and management inputs • Calibration on basis of observed soil water content, biomass, yield and canopy cover • Calibration by adjusting the crop input file Model validation is in progress - Model simulation After model calibration and validation, the model will be used to determine the impact of climate change through simulation of biomass and yields over periods. -

26. - Modelling the impact of climate change on crop yield Input datafor AquaCrop obtained from the mean minimum and maximum air temperatures and total rainfall data from the downscaled GCM data sets, and reference evapotranspiration values). The AquaCrop model to predict potato yields under the following conditions: • Current situation (simulate actual yields) (2000-2010) • Impact (2010-2100): Projected climate for three time periods of ten years: 2020-2030, 2050 - 2060 and 2090-2100 (simulate yields under climate change scenarios) • Adaptation scenarios (2010-2100): Projected climate using recommended adaptation strategy i.e. DI/SI using the AquaCrop model

27. Agro-socio-economicS

32. Thany you