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Oded Achilea, Marked advantages of POTASSIUM NITRATE under water scarcity & salinity
Oded Achilea,
Marked advantages of
POTASSIUM NITRATE
under water scarcity & salinity
Worldwide water scarcity –
supply aspect
Source: “Catastrophic Fall in 2009 Global
Food Production”by Eric deCarbonnel , 2009
University of Oklahoma, Health Sciences Center (2005)
Worldwide water scarcity –
demand aspect
Since 1950
* World population
increased by 100%
* Water consumption
increased by 600%
Irrigation must be made more efficient and
more sustainable
Nutrition techniques must be harnessed to
increase WUE
Two cardinal conclusions
Worldwide water scarcity –
Let’s join efforts
Water
use
efficiency
Water Use Efficiency
Two independent plant functions are involved:
Dry (or fresh) matter produced
Water transpired=
Water management
Biomass production
The Roles of Potassium
Water Use Efficiency
Potassium is a pre-requisite for normal building
process of plant structure
K & Biomass management
Potassium is a pre-requisite for normal functioning of all plant
biochemical and physiological systems 60 enzymes!
K maintains turgor, thus reducing lodging
and enhancing harvesting efficiency
K & Biomass management
Conclusion:
Under normal growing conditions –
The higher the K, the higher biomass production
K & Biomass management
Potassium status of the plant determines the recovery
rate from a drought stress
Skogley, 1976
Severe K deficiency
Moderate K deficiency
Duration of exposure to hot wind (minutes)
K & Water management
0
0.5
1
1.5
2
2.5
3
0 2 4 6 8 10 12 14 16 18 20
Low-K nourished
Normal-K nourished
Time of day
Arqero, Barranco & Benlloch (2006)
Potassium deficiencyincreases stomatal conductance in olive trees
* At a typical summer day during the experiment period (93d.);
Plants under drought regime; Cultivar: ‘Chemalali de Sfax’
Dawn Sunset
During one day
Potassium deficiency –
increases transpiration rate in olive trees
Benlloch-Gonzalez, Arqero, Fournier, Barranco
& Benlloch (2008)
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 10 20 30 40 50 60
Low-K nourished
Normal-K nourished
Cultivar: „Lechin de Granada’
Days from onset of dry period
During the season
Arqero, Barranco & Benlloch (2006)
0
2
4
6
8
Irrigated Drought
Low K Normal K
Water-use
efficiency*
(gDW/L)
* An integration of entire experiment period (93d.);
Cultivar: ‘Chemalali de Sfax’
a
ab
b
Potassium deficiency –reduces Water Use Efficiency in olive trees
Fournier, Roldan, Sanches, Alexandre & Benlloch (2005)
DW (g/plant) K in leaves (umol/g
FW)
WUE (gDW/l)
[K] =0.1 mM
[K] =2.5 mM
0.13
a
0.14
a
58.4
a
110.2
b
1.89
a
2.57
b
Plants were grown for 6 days in nutrient solution with 0.1 or 2.5 mM K+
Potassium deficiency –decrease Water Use Efficiency in sunflower plants
And other crops too:
Faba beans (Abdel-Wahab & Abd-Alla, 1995)
Sugar cane (Sudama & al., 1998)
Rice (Tiwari et al., 1998)
A similar pattern governs both crops
Olive trees (perennial, slow growing species) and in
Sunflower (annual, fast growing species)
Potassium deficiency decrease Water Use Efficiency
Benlloch-Gonzalez, Arqero, Fournier,
Barranco & Benlloch (2008)
Abscisic acid (ABA) has a special role in plant stress
management.
Increased ABA levels stimulate the release of K
from the guard cells, resulting in stomatal closure.
Ethylene is involved too.
PGR’s are involved too in potassium management
and stomatal functioning
Conclusion:
Under normal growing conditions –
The higher the K, the higher the WUE
The roles of Nitrate
Lips, Leidi, Silberbush, Soaresh & Lewis, 1990
Conclusion:Nitrate-nitrogen is markedly more efficient than
ammonium-nitrogen, regarding production of
dry matter, especially under K deficiency
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.1 1 5
Ammonium
Nitrate
Biomass
)gDM / plant)
K+ level in medium solution (mM)
Comparative effects of Nitrate and Ammonium on photosynthesis &
biomass production in wheat
2
4
6
8
10
0.1 1 5
Ammonium
Nitrate
Photosynthesis
)mg CO2 / shoot / h)
Nitrate & biomass management
K+ level in medium solution (mM)
Comparative effects of Nitrate and Ammonium
on transpiration rate of wheat
Lips, Leidi, Silberbush, Soaresh & Lewis, 1990
Nitrogen was applied as calcium-Nitrate or Ammonium-sulfate, @: 4 mM of N,
at various rates of K, as potassium sulfate. Wheat seedlings were grown for 21 days.
400
500
600
700
800
0 1 2 3 4 5
Ammonium
Nitrate
Transpiration
)ml water / gDM)
K+ level in medium solution (mM)
Nitrate & water management
Effects of Nitrate and Ammonium on WUE in wheat
Lips, Leidi, Silberbush, Soaresh & Lewis, 1990
Nitrogen was applied as calcium-Nitrate or Ammonium-sulfate, @: 4 mM of N,
at various rates of K, as potassium sulfate. Wheat seedlings were grown for 21 days.
0.1
0.3
0.5
0.7
0.9
0.1 1 5
Ammonium
Nitrate
WUE
)gDM / L water)
K+ level in medium solution (mM)
Nitrate & WUE
Conclusion:
Under normal growing conditions –
The higher the Nitrate, the higher the WUE
The effect of
POTASSIUM NITRATE
The effect of potassium nitrate on
size distribution of orange fruits
0% 0%2%
11%
23%
27%
12%
4%
0%0% 0% 0%
3%5%
35%
16%
1% 0%
20%
41%
-5%
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
50 55 60 65 70 75 80 85 90 95
Mean fruit diameter (mm)
Fru
it s
ize
sh
are
in
tre
atm
en
t
Control- 0 application Grower's practice
Bonus-npK Multi-K 3 X 5%
„Jaffa’ oranges, in Israel, 2002
Increasing Mango trees productivity by spraying
Potassium Nitrate, via the increase in WUE
1
1.5
2
2.5
3
3.5
4
4.5
Julie Graham Tomi Atkins
Control
PN 6% - May
PN 6% - June
WUE
)mM CO2 / MH2O)
Cultivars tested
Spraying treatments
a a a
b
b
b
a
ab
Shongwe & Roberts-Nkrumah, Trinidad, 1996
b
Kafkafi, Walerstein & Feigenbaum, 1971
WUE
mL water /
g fresh fruit
Yield
(g/plant)
N (g/plant)N form (%)
Amm.
Nitrate
Multi-K(NO3- : NH4
+)
23**2550*06.3100 : 0
28**1980*4.46.370 : 30
29**1200*8.76.363 : 37
34**1000*13.26.359 : 41
23**3430*012.6100 : 0
* Significance at 0.1% probability; ** At 1% probability
Increased of WUE by nutrigation of
Potassium Nitrate, in Tomatoes
Potassium Nitrateincreases WUE
Hence:Every m3 of water
can produce more if combined with
Potassium Nitrate
The problem of man-made salinization
Severely salinated fields in central California
Washington State University (2001)
Country Badly salinized as
% of irrigated area
India 37 – 60
Iraq 50
Egypt 30
Pakistan 25
U.S. 23
Australia 20
China 15
Pakistan 14
Israel 13
Irrigation-induced salinization
Most frequent ions involved in salinity situations are:
Anions: Cl- , SO4-2, B-
Cations: Na+
Elevated EC
Specific toxicity
The mechanism of salinity damage
A simplified model
Photosynthesis
The K+ shuttle facilitates NO3-
movement upwards, and malate-
downwards.
Proteins are produced.
Roots are well nourished
NO3-
HCO3-
Soil Solution
Malate
K+
NO3-
Proteins
N.R.
K+
NO3-
After Ben-Asher and Pacardo, 1997
Normal metabolism at
non-saline conditions
in soil
A simplified model of chloride
accumulationPhotosynthesis
The K+ shuttle moves Cl- upwards
and malate downwards.
Protein production is halted
NO3-
HCO3-
Soil Solution
Malate
K+
NO3-
K+Cl-
Cl- Toxicity
Cl-
Cl- suppresses NO3- uptake
After Ben-Asher and Pacardo, 1997
in leaf-tips at
excessive Cl- in soil
The effect of Nitratein reducing
Cl- absorption
Antagonistic effect of Nitrate on chloride
in AVOCADO
Bar, Kafkafi & Lahav, 1987
Relieving chloride toxicity in avocado by increasing nitrate
concentration in irrigation water containing 16 mM Cl
Avocado, („Schmidt‟ Mex. salinity-sensitive) rootstock, Israel
Bar, Kafkafi & Lahav, 1987
0
0.5
1
1.5
2
2 4 10
Chloride in irrigation water (meq./L)
Nitrate combats chloride in irrigation water
2
8
16
Nitrate in irrigation
water (meq./L)Cl- in
leaves
(% of D.M)
Antagonistic effect of Nitrate on chloride
in AVOCADO
Lewis, Leidi & Lips, 1989
10
15
20
25
30
35
40
45
0 30 50 80
Nitrate- fed (4mM N)
Ammonium- fed (4mM N)
Plant shoot
fresh mass
(g)
Chloride in irrigation water (mM)
aa
b
a
aa
b
Antagonistic effect of Nitrate on chloride in MAIZE
b
a
The importance of K / Naratio in plant metabolism
Na’s toxicity stems from its competition with K
for enzymatic binding sites (60 of them, remember?)
High K / Na ratio in the plant
is more important than maintaining
low Na concentration
The importance of K / Na
The effect of
Potassium Nitrate
in increasing biomass production
under salinity conditions
30
80
130
180
230
280
0 2 4 6 8 10 12 14
2 mM8 mM14 mM
Potassium nitrate
Treatments
Ear
Yie
ld (
F.
W.g
/pla
nt)
E. C. of salinized nutrient solution (dS/m)
Double
yield
Imas & Feigin, 1995. Israel
Effect of salinity and Potassium Nitrate on
yield of Sweet Corn (cv. Jubilee)
0
100
200
300
400
500
To
tal
yie
ld (
g/p
lan
t)
*Montecarlo *Pearson
Control Salinized Salinized + Multi-K
Satti et Al. 1994
a
b
a
b
cc
Potassium Nitrate reverses the adverse effects of
salinity on Greenhouse TOMATOES
Potassium Nitrate increases fresh yield in greenhouse
CHINESE CABBAGE (cv. Kazumi) under salinity
780
860
940
1020
1100
1180
Fresh
Yie
ld (
g/p
lan
t)
0 0 1 5 10
Feigin et Al., 1990, Israel
a
a
b
ab
Data collected at 55 D.A.T
PN rate (mM)
EC= 1.8 EC= 5.0
EC= 6.0
EC= 5.5
EC= 6.5
ab
320
350
380
410
440
470
Fre
sh Y
ield
(g/p
lan
t)
0 0 1 5 10
Feigin et Al., 1990, Israel
a
c
a
b
ab
Data collected at 63 D.A.T
EC= 1.8 EC= 5.0 EC= 6.0EC= 5.5 EC= 6.5
PN rate (mM)
Potassium Nitrate increases salinity resistance in
greenhouse LETTUCE (cv. Salinas) under salinity
Under normal growing conditions
a modest application of Potassium Nitrate,
enables 10-35% higher harvested produce
from a given water quota
Under salinity conditions
a modest application of Potassium Nitrate
enables maintaining harvested produce
in spite of elevated EC values
