IMPACTS OF LOW WATER POTENTIAL ON SOIL SALINITY
AND ITS EFFECTS ON CRANBERRY DEVELOPMENT
Marie-Élise Samson
J. FORTIN, J. CARON, S. PÉPIN
NACREW
Québec 2013
Introduction
 Agriculture consumes each year 70% of water resources (Burton, 2010)
 Worldwide, 1/3 of irrigated areas presents salinity issues (Bohn and al.,
2001)
A good irrigation management is essential in cranberry
production to maintain water resources, avoid salinity problems
and ensure good economic returns.
Introduction
• In cranberry production, irrigation
thresholds were suggested :
-4 kPa to -6,5 kPa (Bonin, 2008)
• Represents a decrease in soil water
content
• Affects the movement of mineral
fertilizers applied during plant
growth
Hoffman and al. (1990)
Deficit irrigation could cause salinity problems in the root layer and
lead to osmotic stress in cranberry plants
Objective
 Evaluate the effects of different irrigation regimes on the ions profile in
a sandy matrix and their impacts on plant development
 Determine a soil electrical conductivity threshold in cranberry
production
Material and methods
EXPERIMENTS SUMMER 2012 :
 2 matric potential thresholds
-5.5 kPa (moist treatment)
-8.5 kPa (dry treatment)
 A control and three salinity levels obtained with KCl
S1 = 125Kg/ha K2O in form of K2SO4
S2 = 125 Kg / ha of K2O in form of KCl
S3 = 250 Kg / ha of K2O in form of KCl
S4 = 375 Kg / ha of K2O in form of KCl
Material and methods
MEASUREMENTS :
• Matric potential (Tensiometers)
• Water content (TDR, 5TE and EC5)
• Electrical conductivity
•
•
•
•
(Lysimeters, TDR and 5TE)
Ions concentrations (Lysimeters)
Photosynthesis (Li-Cor 6 400)
Pressure-Volume curves (Pressure chamber)
Abortion rates, growth and yield measurements
Results
2.0
1.8
1.6
EC (dS/m)
1.4
1.2
1.0
375 Kg/ha K2O
0.8
250 Kg/ha K2O
125 Kg/ha K2O
0.6
Control
0.4
0.2
0.0
Date
EC (dS/m) obtained weekly with lysimeters
Results
PHOTOSYNTHESIS MEASUREMENTS
14
Photosynthesis (µmol CO2 m-2s-1)
12
10
8
June 2012
July 2012
6
4
2
0
Dry
Dry
Dry
Dry
Moist
Moist
Moist
Moist
Control 125Kg/ha 250Kg/ha 375Kg/ha Control 125Kg/ha 250Kg/ha 375Kg/ha
Treatments
Results
ORIGINAL OSMOTIC PRESSURE
2
Original osmotic pressure
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Ladiges (1975)
Dry
Dry
Dry
Dry
Moist
Moist
Moist
Moist
Control 125Kg/ha 250 Kg/ha 375Kg/ha Control 125 Kg/ha 250Kg/ha 375 Kg/ha
Treatment
Results
YIELD AND GROWTH MEASUREMENTS
The different treatments showed no significant effects on…
•
•
•
•
•
Abortion rate
Growth measurements
Yield
Fruit size
Number of seeds in each fruit
Discussion
0.7
0.7
0.6
0.6
375 Kg/ha K2O
0.2
0.0
10/04/2012
23/07/2012
Date
Water extraction (1:1) EC (dS/m) in the
greenhouse at the beginning and at the end of
the experiment
0.0
0.1
0.1
0.4
0.5
250 Kg/ha K2O
0.3
125Kg/ha K2O
0.3
0.2
Control
0.4
CE
EC (dS/m)
EC (dS/m)
0.5
Prod A
Bieler
Prod B
Erable
Prod C
Nadeau
Prod D
Ncan
Prod
Water extraction (1:1)
EC (dS/m) obtained
from four different fields during summers
2010 and 2011
Conclusion
 We obtained salinity levels encountered in the fields
 Conditions were not stressful for plants
 A salinity inferior to 1 dS/m is not a limiting factor for cranberry
production
Further experiments (2013-2014) should help us find a salinity
threshold in cranberry production. The effects of subsurface
irrigation will also be investigated.
Thank you!

Bohn, H. L., McNeal, B. L., and O'Connor, G. A. 2001. "Soil chemistry." 3e /Ed. Wiley. New York. xi,
307 p.

Burton, M. 2010. "Irrigation management : principles and practices." CABI North American Office.
Cambridge, MA. x, 375 p.

Hoffman, G. J., Howell, T. A., and Solomon, K. H. é. 1990. "Management of farm irrigation systems."
American Society of Agricultural Engineers. St-Joseph,MI. 1015 p.

Ladiges, P. Y. 1975. Some aspects of tissue water relations in three populations of eucalyptus viminalis
labill. New Phytologist. 75: 53-62.

Minville, S. 2007. "État de l'écosystème aquatique du bassin versant de la rivière Bécancour : faits
saillants 2004-2006, Québec, ministère du Développement durable, de l'Environnement et des Parcs,
Direction du suivi de l'état de l'environnement, ISBN 978-2-550-51516-6 (PDF)." 15p.