Presentation by Mr Francisco Pedrero

1. Water and Soil
management in
salt-affected areas of
climate change
Water management in land reclamation
Areas of Southern Spain
Dr. FRANCISCO PEDRERO SALCEDO
Agriculture Engineer Irrigation Department
Spanish National Research Council (CSIC)
Applied Biology and Soil Sciences (CEBAS)

2. How to face this challenge for the agriculture of the future?
- Locate, diagnose and map the problem
- Monitoring continuously the salinity levels
- Establishment of measures in affected areas to
maintain salinity at acceptable levels.
- Recovery of degraded and viable soils from a
technical, environmental and economic point of view,
through sustainable irrigation water management
strategies (blending, secuential reuse,…)

3. The Region of Murcia

4. An estimated 100,000 irrigated hectares are irrigated with water from aquifers, of
which 85% have a very high level of salts
Salinity problem

5. Irrigation Management Strategies (at farm and distric level)
132 m
59 m
82 m
45 m
105 m
48 m
106 m
30 m
135 m
43 m
Aquifer depth
Optimal groundwater recharge
5
Km
Wastewater treatment plant
1
3
5
4
2

6. Use of reclaimed water and Regulated Deficit Irrigation (RDI) on mandarin
and grapefruit
2008-2020Evaluate the agricultural impact of using
reclaimed water for irrigation of citrus trees
under optimum and deficit irrigation conditions
and to assess the use of GIS tools for planning and
management of water reuse projects.

7. Long term effects

8. Ctr
J OJ F M A M J A NS D
RDI
100 % ETc
50 % ETc
Dual-Water
J OJ F M A M J A NS D
Regulated Saline
Irrigation “RSI”
100 % ETc
ECw > 4ECw ≈ 1 ECw ≈ 1
ECw > 4 ECw > 4ECw ≈ 1
NEW treatments
Mixing irrigation Strategies

10. Water and Agriculture Research Platform CEBAS-CSIC

11. EXPERIMENTAL FIELD IN ROLDAN WWTP (MURCIA,SPAIN)
 Removal efficiency ~60%
 E. coli ~100%

12. Simplified treatments
Brine reuse on halophytes plants
1-2
ds/m
3-4
ds/m 2 ds/m
salty
Brine
citrus
tomato
salicornia
3-4
ds/m
4-5 ds/m
4-5
ds/m
sensible
Salt
resistant
SALINITY

13. Establishment year
First irrigation
Surface of irrigable area (has.)
Community members
Yearly water supply(Hm3)
ResourcesfromtheTagus-Seguradiversion(Hm3)
ResourcesfromtheMojóndesalinationplant.(Hm3)
Resourcesfromwastewatertreatmentplants(Hm3)
Resourcesfrom the Segura basin (Hm3)
1952
1979
41,294
9,896
141.9
122
4.2
2.2
11.68
General Data

14. crop
distribution
HORTICULTURE
CITRUS FRUITS
GREENHOUSES
FRUIT TREES
Drip
96%
Surface
2%
Trickle
2%

15. Water Resources Mix
- RW - Tagus Transfer - S.Basin - Drought Wells - Market Transfer - Desalination

16. RW: F.
Álamo:
0,654 hm3
RW: Torre-
Pacheco:
1,825 hm3
RW: S. Javier:
2,894 hm3
RW: Balsicas-
Roldán: 1,0
hm3
RW: Los Alcázares:
2,611 hm3
RW: La Aljorra:
0,270 hm3
RW: San Pedro:
2,430 hm3
Max Total RW: 11,684 hm3
Reclaimed Water Use & Desalination
DS:
Escombreras
DS: Torrevieja

17. “ T h e M i x ”
• High EC
Challenges
TS transfer: 900 uS/cm
Desalinated water: 220 uS/cm
RW*: 4,000- 8,000 uS/cm
• Nutrients (nitrogen and phosphorous)
• Lack of oxygen/ H2S: confined underground spaces
• Portable gas detector
• Moving elements out
• Water reservoirs: excessive algae growth
Mix: < 1,200 uS/cm
• Ultrasound irradiation-coagulation
• Copper based compunds
• Boron Mix: < 0,5 mg/L

18. Minor Sea Lagoon Issues
Phosphates: detergents, fertilizers, sewage
Sea water intrusion