Transcript Document

Chloride Research: What Have
We Learned?
C. A. Grant1, R. E. Lamond2 , R. M. Mohr1 and
R. E. Engel3
1AAFC
- Brandon Research Centre
2Kansas State University
3Montana State University
History of Chloride
• Discovered in Sweden in 1774 by
Carl Wilhelm Scheele
• Present in many salts, including
KCl, CaCl2 and NaCl
• Recognized as fertilizer as far
back as mid 1800’s
• NaCl applied to “stiffen straw”
• Cl- viewed as active ingredient
History of Chloride
• Chloride recognised as an
essential nutrient in 1954
• Required in very small amounts
for crop growth (~100 mg kg-1)
• Deficiency induced in nutrient
solutions
• Cl- widespread in soil and water
• Responses considered unlikely
in field
What
Does ClDeficiency Look
Like?
•
•
•
•
Premature wilting
Chlorosis of newly emerging leaves
Reduced shoot and root growth
Roots may show “herring bone”
pattern
• Leaf cupping may occur
Field responses occurred where
Cl- was above biochemical needs
• Late 1950’s to early 1960’s
• Sugar beets in Manitoba (Soper)
• Corn in US (Younts and
Musgrave)
• Increased yield and reduced
stalk rot
Effect of K Source and Placement
on Grain Yield of Field-Grown Corn
45
Yield (bu acre -1 )
40
35
30
20 lb K2O acre-1
None
In-Row
Broadcast
25
20
15
10
5
0
Control
Younts and Musgrave 1958
KCl
K2SO4
Effect of K Source and Rate on
Stalk Rot in Field-Grown Corn
24
Stalk Rot (%)
22
KCl
K2SO4
20
18
16
14
12
0
20
60
80
-1
K Rate (lb K2O acre )
Younts and Musgrave 1958
100
Field responses occurred where
Cl- was above biochemical needs
• Early 1970’s
• Coconut and other plantation
crops in Philippines (von
Uexkull)
• Late 1970’s - early 1980’s
• Winter wheat in Europe
(Russell) and USA (Powelson
and Jackson; Taylor and
Christenson)
Winter Wheat Grain Yield as
Function of N Source
8
Grain Yield (T ha
-1
)
7
6
5
(NH4)2SO4
NH4Cl
Ca(NO3)2
4
3
2
1
0
Site A
Christensen et al. (1981)
Site B
Reponses Not Due to
“Biochemical” Deficiency
•
•
•
•
•
•
•
Water relations?
Effects on plant development?
Nitrification inhibitor?
Transport of other nutrients in plant?
Reducing late season lodging?
Kernel weight?
Disease effects?
Response occurs at Cl- much higher
than measured essential level
Take-all root rot of winter wheat was
reduced by KCl in Oregon
Oregon results triggered
interest in Cl- in Great Plains
• Responses to KCl had been noted on
high K soils in Montana
• Skogley and Haby (1981)
• Winter wheat, spring wheat, barley,
potatoes, alfalfa and more
• Suggested a problem with K soil test
prediction
• Cl- response could be part of the
reason
Great Plains Research
• Will crops on the Great Plains
respond to Cl-?
• Which crops will respond?
• What is the mechanism for Clresponse?
• Can we predict where responses
will occur?
Cl- has improved crop yields in
the Great Plains
• Over 210 trials in KS, MN, MT, ND,
SD, MB and SK have evaluated Clresponse in wheat and barley
• Significant yield response in 48%
of trials
• Average response of ~5 bu/A
• Cl- responses also occurred in
other crops
Wheat and barley responded to
KCl while oats did not
8 site-years in South Dakota
Grain Yield (Mg ha -1 )
4.0
3.5
0 KCl
187 KCl
3.0
2.5
2.0
Wheat
Fixen et al. (1986)
Barley
Oats
Chloride fertilization increased
grain corn yield in Kansas
Brown County - 2000
Grain Yield (bu acre
-1
)
96
94
20 Cl
40 Cl
92
90
88
86
84
82
Control
Lamond et al. 2000
KCl
NaCl
CaCl2
Chloride fertilization increased
grain sorghum in Kansas
Brown County- 2000
Grain Yield (bu acre -1 )
100
20 Cl
40 Cl
98
96
94
92
90
88
86
84
82
80
Control
Lamond et al. 2000
KCl
NaCl
CaCl2
Responses to Cl- are cultivar
dependant
• Cultivar differences occur in
barley and wheat
• Both spring and winter
wheat
• Some of the differences may
be due to disease
susceptibility
Summary of grain yield responses to
addition of 50 kg Cl- ha-1 (Manitoba, 1989-91)
Average Yield Response
(Kg ha-1)
Cultivar
Sites with yield
increase
Responsive
sites
All sites
Katepwa
0 of 8
--
-10
Katepwa
0 of 4
--
-16
Roblin
1 of 4
493
137
Biggar
2 of 4
333
150
Marshall
2 of 4
363
116
Mohr
Chloride Variety Trials
• North American Cl- study
• Texas, Kansas, South Dakota,
North Dakota and Manitoba
• 15 winter wheat or spring wheat
varieties at each location
• Treatments: 0 Cl- and 40 lb/A Cl-
Response of Winter Wheat
Cultivars to Cl- fertilization
12
Responsive
Yield Response
(bu acre-1)
10
8
Non-responsive
6
4
2
Lamond et al. 2000
ter
Cu
s
a
llal
7
213
Og
a
3
216
92
Ka
rl
r
ge
Jag
64
um
ph
Tri
Cim
ar r
o
n
0
Response of Spring or Durum Wheat
Cultivars to Cl- Fertilization
7
Responsive
Yield Response
-1
(bu acre )
6
5
4
3
Non-responsive
2
1
d in
Gr
an
eal
ber
Ta
Ba
rrie
nty
CD
CT
Grant et al. 2000
Pl e
Ka
rm
a
0
Yield Increase May Be Due To
Disease Suppression
• Wheat: take-all root rot,
common root rot, fusarium root
rot, stripe rust, leaf rust,
septoria, tanspot
• Barley: common root rot,
fusarium root rot, spot blotch
• Corn: stalk rot
KCl application reduced common
root rot in barley
95
Root Rot Rating (%)
90
85
80
75
70
65
60
Control
Grant and Bailey 1994
KCl
KNO3
CaCl2
KCl application reduced common
root rot in wheat
1= clean and 4 = severe
2.5
Root Rot Rating
2.0
1.5
0 Cl
50 Cl
1.0
0.5
0.0
Carman
Mohr et al 1992
Portage
Cl- reduced leaf rust in winter wheat in
Texas
Miller reported at
PPI-FAR.org
Application Of Cl- Decreased Leaf
Diseases In Marshall Spring Wheat
Septoria and tanspot leaf spot complex
PPI-FAR.org
KCl or Tilt decreased leaf disease and
increased grain yield
Butte spring wheat
Flandreau, SD, 1984.
Fixen et al. 1986
PPI-FAR.org
Why Would Cl- Decrease
Disease Problems?
• Increased water potential
restricts infection by pathogens?
• Plants are better able to
withstand disease?
• Lowers tissue NO3- which
inhibits crop susceptibility?
• Increases soil NH4+ which
inhibits pathogens?
• Nitrification inhibition
Oregon Studies Associated ClEffect With Plant Water Potential
• Cl- treated plants were more
erect at mid-day
• Cl- might affect water potential
• Increased water potential may
reduce susceptibility to
disease
Osmotic potential of winter wheat
leaves as related to Cl- concentration
Osmotic Potential (bars)
-22
-21
-20
-19
0.0
0.2
0.4
0.6
0.8
-18
Chloride Concentration (%)
Christensen et al. 1981
1.0
Cl- increased leaf relative water content
and grain yield in Butte spring wheat
Flandreau, SD, 1984
Fixen et al. 1986
Effect of K source on tissue nitrate
Tissue NO3-N at Boot
(g/kg)
2.0
Control
K2SO4
KCl
1.5
1.0
0.5
0.0
ri
r
Ca
Timm et al. 1986
n
o
t
g
n
a
n
tu
r
Fo
M
t
o
in
rs
e
w
o
P
e
k
La
W
is
ill
n
o
t
Grain Yield (bu/acre)
Chloride reduced the effect of take-all
on grain yield
Christensen et al. 1990
1986-88
Cl- Sometimes Increased Yield
Without Affecting Disease
• Enhanced crop development
• Higher kernel weight
• Longer grain fill
• Greater rate of kernel growth
• Better water relations
• Reduced lodging
Plant development
K2SO4
KCl
Cl- addition increased winter wheat
kernel weight
1000 Kernel Weight (g)
45
- Cl
+ Cl
40
35
30
25
20
15
1
3
4
5
6
Site
Engel et al. 1994
7
8
9
Physiological
Leaf
Spot
Physiological Leaf Spot
“Physiological Leaf Spot”
• Occurs in winter and durum
wheat
• Recently reported in barley
• Looks similar to tanspot
disease
• Related to crop genetics
• Redwin, Sierra, CDC
Kestrel are susceptible
Leaf spots severity is strongly related
to plant Cl!
Leaf spot severity, %
Redwin winter wheat
50
40
Y = 1.01 + 39.8 exp
30
• 10 field locations MT
(-3.89 X)
• 1.0 g kg-1 plant Cl
R2 = 0.82
20
• Severity increases
10
0
exponentially at plant Cl
< 1.0 g kg-1
no lesions
0
2
4
Plant Cl, g kg
6
-1
8
Leaf Spot Severity and Plant ClKestrel winter wheat
Leaf spot severity, %
50
40
Y = 1.67 + 64.6 exp (-2.45 X)
30
R = 0.98
• 6 field locations in
MT
• Relationship
expressed is similar
to Redwin
• Break point = 1.5 g
kg-1 plant Cl
2
20
10
0
0
2
4
Plant Cl, g kg
6
-1
8
Chloride Deficient Leaf Spot
This phenomenon is not a disease !
• Applications of fungicides
have no effect on
symptoms
• There is no infectious
organism on affected
tissue
• Symptoms can be
reproduced in solution
culture
WB881 durum wheat
- 0 Cl dose -
CDC Kestrel winter wheat
K2SO4
KCl
“Chloride deficient leaf spot syndrome”
Soil testing can help predict Cl
response
Category
Low
Medium
High
Response
Soil Cl Frequency Average
lb/A-2 ft
%
bu/A
< 30
69
4.0
31- 60
31
2.6
> 60
0
0.3
Based on responsive spring wheat varieties grown
at 36 locations in South Dakota.
Yield deficit from max., kg ha
-1
Yield response in wheat (size and probability)
increase as plant Cl falls below 4 g kg-1
maximum response line
1200
NS
800
Significant
400
0
-400
0
2
4
6
Plant Cl, g kg
8
-1
10
Relationship between available Cland tissue Cl- in Katepwa wheat
Plant Cl Concentration (g kg-1)
10
2
KCl R = 0.68
NaCl R2 = 0.73
8
6
4
2
0
0
20
40
60
80
100
-1
Soil (to 60 cm) + Fertilizer Cl (kg ha )
Mohr
Soil test recommendations
vary with region
• Montana, North Dakota and
Manitoba
• Soil Cl to 24” + fertilizer
should equal 30 lb Cl- acre-1
• Saskatchewan
• Apply if soil Cl- to 12” is below
16 lb acre-1
Soil test Cl- content in samples
taken by Agvise Lab
Low Soil Cl- Does Not
Guarantee a Reponse
•
•
•
•
Cultivar effects
Disease pressure
Moisture regime
Other stress effects
Soil testing identifies sites where
responses are more likely to occur
What Have We Learned?
• Cl- responses can occur under
field situations
• Not strictly a biochemical
requirement
• Responses are strongly
related to cultivar
What Have We Learned?
• Disease suppression plays a
role
• Not the sole reason for
benefits
• “Physiological leaf spot” is Cldeficiency in susceptible
cultivars
• Cl- application cures the
problem
What Have We Learned?
• Other benefits occur
• Kernel weight
• Water relations
• Lodging resistance
• Crop development
• Soil testing and tissue testing can
help predict responses
Questions?