Strategic Approaches to Integrated Management of Land, Strategic Approaches to Integrated Management of Land, Water and Livelihoods along an Aridity Gradient: Water and Livelihoods along an Aridity Gradient:

Southern Tunisia siteSouthern Tunisia site

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

TeamTeamBiophysical Socio-Economic

H. Khatteli M. Sghaier

M. Ouessar M. Abdeladhim

K. Nagaz R. Bechir

M. Ben Zaied

A. Zerrim

F. El Mokh

A. Hachani

S1 (North): Tunis (semi arid)

S2 (Centre): Sidi Bouzid/Kasserine (semi arid)

S3 (South) : Medenine/Tataouine (arid)

Study sites in TunisiaS1

S2

S3

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

MODELLING OLIVE GROVES MODELLING OLIVE GROVES VULNERABILITYVULNERABILITY

TO CCTO CC

Images Landsat 5 and

7 Soil map Land use

map

HidroMOREHidroMORE

NDVI

Conceptuel Model

Geométric and atmospheric correction

climatic data: Baseline period, until 2030 and until 2090

collecting data Treatement

9

41

Slightly suitable

Moderately suitable suitable

Baseline period 28% 46% 26%

Horizon 2030 19% 68% 13%

Horizon 2090 24% 76% 0

GABION CHECK DAMS EFFICIENCYGABION CHECK DAMS EFFICIENCY

WATER MANAGEMENT IN THE WATER MANAGEMENT IN THE IRRIGATED AREAIRRIGATED AREA

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)

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 

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)

Results

First year of experimentData collected on Potato, carrot & green bean,Pepper experiment is still in progress

0

1

2

3

4

5

6

7

Initiale 15/11/2012 01/01/2013 23/01/2013Date

EC

e (d

S/m

)

FMDI70

SWB100

Potato

0

1

2

3

4

5

6

7

Initiale 05/11/2012 05/12/2012 05/01/2013 19/02/2013

Date

EC

e (d

S/m

)

FMDI70

SWB100

Carrot

0

1

2

3

4

5

6

7

Initiale 08/11/2012 27/11/2012 12/12/2012 15/01/2013 03/02/2013

Date

EC

e (d

S/m

)

FMDI70

SWB100

Green bean

0

5

10

15

20

25

30

SWB

100

DI7

0

FM

SWB

100

DI7

0

FM

SWB

100

DI7

0

FM

SWB

100

DI7

0

FM

Potato Carrot Green bean (Luz diotono)

Green bean (Local)

Treatments

Yiel

d (t/

ha)

23%

37%

14%24%

7%7%20%

18%

YieldLSD (5%)

Carrot, 3.627Potato, 3,224

Green bean Luz, 4.698Geen bean L, 4.749

0

100

200

300

400

500

600

SWB

100

DI7

0

FM

SWB

100

DI7

0

FM

SWB

100

DI7

0

FM

Potato Carrot Green bean

Treatments

Irrig

atio

n su

pply

(mm

)

14%

18%

12,5%

Water applied

30%

0

2

4

6

8

10

12

SWB

100

DI7

0

FM

SWB

100

DI7

0

FM

SWB

100

DI7

0

FM

SWB

100

DI7

0

FM

Potato Carrot Green bean (Luz diotono)

Green bean (Local)

Treatments

WP

(kg/

m3)

Water productivity LSD (5%)Carrot, 1.578Potato, 1.797

Green bean Luz, 2.002Geen bean L, 2.037

DI WPCarrot, 22%Potato, 9.9%

Green bean, 32%

FM WP Carrot, 35%Potato, 44%

Green bean, 28%

• 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

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

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

MPDELLING CLIMATE CHANGE MPDELLING CLIMATE CHANGE IMPACT AND ADAPTATION IMPACT AND ADAPTATION

STRATEGY ASSESSMENT ON CROP STRATEGY ASSESSMENT ON CROP PRODUCTION PRODUCTION

- 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.

-

- Modelling the impact of climate change on crop yield

Input data for 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

AGRO-SOCIO-ECONOMICSAGRO-SOCIO-ECONOMICS

Thany youThany you