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Does Chloride Deserve My Attention?. American Society of Agronomy Annual Meeting Denver, Colorado November 4, 2003 Paul Fixen Potash & Phosphate Institute. This slide set available at: http://www.ppi-ppic.org/ppiweb/napro.nsf - PowerPoint PPT Presentation
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Does Chloride Deserve My Does Chloride Deserve My Attention?Attention?
American Society of Agronomy American Society of Agronomy
Annual MeetingAnnual Meeting
Denver, ColoradoDenver, Colorado
November 4, 2003November 4, 2003
Paul FixenPaul Fixen
Potash & Phosphate InstitutePotash & Phosphate Institute
This slide set available at: http://www.ppi-ppic.org/ppiweb/napro.nsfAdditional Cl information at: www.ppi-ppic.org/chloride/index.html
Related questionsRelated questions
Can Cl significantly influencesignificantly influence crop growth and development? Chemical and nutritional basics
Does Cl influence the crops I managecrops I manage? Crop sensitivity for deficiency and toxicity
Is Cl an important factor in mymy trade area? Nutrient cycling
Can Cl be managed economically? Dr. Grant and Dr. Lamond
Chlorine the elementChlorine the element
One of the halogensOne of the halogensOccurs in nature only as ClOccurs in nature only as Cl- -
Chloride chemistry terminologyChloride chemistry terminology
Chlorine (Cl):Chlorine (Cl): The name of the element Chlorine gas (ClChlorine gas (Cl22):): A greenish yellow gas with a
choking odor; used to purify municipal water Hypochlorite (OClHypochlorite (OCl--):): Forms when Cl2 reacts
with water; A powerful oxidizing agent sold as laundry bleach
Chloride (ClChloride (Cl--):): The naturally occurring stable form of the element
Chloride in our environmentChloride in our environment
Earth’s crust 0.15%Seawater 1.9%Plants 0.1-1%Table salt 60%Muriate of potash 47%
Chloride - an essential plant nutrientChloride - an essential plant nutrient
Earliest report of Cl crop response in mid 1800s1800s in England ... NaCl (salt) topdressed to stiffen barley straw
Recognized as an essential micro- nutrient since the 1950s1950s
Research in the late 1970s1970s revealed insufficient levels in many areas Phillipines, Europe, NW USA
Wheat and barley responses to Wheat and barley responses to chloride in the Great Plainschloride in the Great Plains
(Over 200 evaluations in KS, MN, MT, ND, SD, SK, TX)(Over 200 evaluations in KS, MN, MT, ND, SD, SK, TX)
Response expressed as wheat bushels
Range of response: -3 to +18 bu/A
Average of all: 2.4 bu/A
(includes nonresponsive varieties & high Cl sites)
Frequency of significant response: 48%
Average significant response: 5.2 bu/A
Roles of chloride in plantsRoles of chloride in plants
Stomatal operation
Due to the accumulation Due to the accumulation of Cl in chloroplasts, of Cl in chloroplasts,
this biochemical need is this biochemical need is likely always met underlikely always met under
field conditions field conditions
Photosynthesis and enzyme activationPhotosyntheticPhotosynthetic
electron transportelectron transport
Transport of other nutrients in plantsWater movement in the cell
Effects of chloride addition on plantsEffects of chloride addition on plants
Disease suppression/enhanced host tolerance
Reduced late season lodging
+Cl-Cl
Accelerated plant
development Increased kernel size or plumpness
Wheat, barley and millet diseases Wheat, barley and millet diseases suppressed by chloride additionsuppressed by chloride addition
Stripe rust
Tanspot
Leaf rust
Take-allCommon root rot
Spot blotch
Septoria Powdery Mildew
Tanspot and Septoria suppresion on flag Tanspot and Septoria suppresion on flag leaves of Marshall spring wheat near leaves of Marshall spring wheat near
Watertown, South Dakota in 1985Watertown, South Dakota in 1985
(Septoria and tanspot incited by Septoria avenae f. sp. triticea and Pyrenophora tritiic-repentis)(Septoria and tanspot incited by Septoria avenae f. sp. triticea and Pyrenophora tritiic-repentis)
56 lb Cl/A
No Cl
Leaf rust suppression on flag leaves of Leaf rust suppression on flag leaves of winter wheat in Bosque county Texaswinter wheat in Bosque county Texas
Pioneer 2158 at anthesis. NH4Cl applied at 40 lbs Cl/A
Miller, Texas A&M Univ.
Other diseases suppressed by Other diseases suppressed by chloride additionchloride addition
Corn Stalk rot
Potatoes Hollow heart, Brown center
Celery Fusarium yellows
Coconut palm Gray leafspot
Rice Stem rot, Sheath blight
Mechanism of disease effectsMechanism of disease effects
Suppression of pathogen Increased NH4
+ uptake – rhizosphere acidification – competitive disadvantage for root pathogens
Increased Mn availability Reduced plant NO3
- concentrations
Increased leaf turgor potential
Enhanced host tolerance Increased plant turgor reduces the effect of the
pathogen on crop yield
Chloride accumulates in most plantsChloride accumulates in most plants
Leaf bladecollar
20 fold range in plant concentration
Chloride toxicityChloride toxicity
Grundon, Univ. of Queensland; Gartel, Germany
Grape
Marginal necrosis caused byMarginal necrosis caused byspraying Mg or NaCl to preventspraying Mg or NaCl to prevent
stem necrosisstem necrosis
Soybean
Droughted appearance andDroughted appearance andpale green marginal necrosispale green marginal necrosis
Fall soil Cl >60 ppm, leaf > 0.9% Cl Fall soil Cl >60 ppm, leaf > 0.9% Cl for susceptible cultivars (Univ. GA)for susceptible cultivars (Univ. GA)
Shows firstShows firston older leaves,on older leaves,then works itsthen works its
way up the plantway up the plant
Toxic effects of chlorideToxic effects of chlorideSome plants are sensitive to Cl excesses:
Some tree, vine, citrus, vegetable, conifer, and ornamental plants
Tobacco Certain soybean varieties grown in the SE U.S.
Conditions where excesses may occur: Low-lying poorly drained areas Where high water tables occur Confined soils - greenhouses High Cl irrigation water
Cl deficient leaf spot syndromeCl deficient leaf spot syndrome
Leaf spot of previously unknown origin First observed in 1991 on Redwin and Manning
winter wheat in Montana Appears similar to tanspot disease but is not
caused by a microorganism Occurs when wheat tissue Cl < 0.1% and soil Cl
< 10 lb/A (0-24”) Barley flag leaf Cl < 0.09% (Oregon State Univ.)
Not shown by all varieties that are Cl deficient No distinctive deficiency symptoms for all varieties
Cl deficient leaf spot syndrome in Cl deficient leaf spot syndrome in CDC Kestrel winter wheatCDC Kestrel winter wheat
F F-1 F-2F F-1 F-2 F F-1 F-2F F-1 F-2
No ClNo Cl 20 lb Cl/A20 lb Cl/A
Engel et al., Montana State University
Cl deficient leaf spot syndromeCl deficient leaf spot syndrome in winter in winter wheat at mild stage (left)wheat at mild stage (left)
Engel, Montana State University20 lbs Cl/A20 lbs Cl/A
Cl deficient leaf spot syndromeCl deficient leaf spot syndrome on durum on durum grown hydroponically in a growth roomgrown hydroponically in a growth room
Western Plant Breeders 881 durum (WB881)
Engel, Montana State University
Bromide does not substitute for Bromide does not substitute for chloridechloride
WB881 Durum
Engel, Montana State University
Crops known to respond positively to Crops known to respond positively to Cl in the fieldCl in the field
Winter wheat Spring wheat Durum wheat Barley Corn Grain sorghum
Potatoes Rice Pearl millet Coconut palm Celery
Chloride cycling in agroecosystemsChloride cycling in agroecosystems
Sources of Cl Wet deposition Muriate of potash fertilizer (47%) Manure Irrigation water
Losses of Cl Crop removal Leaching
Chloride ion Chloride ion wet depositionwet deposition
Cl, kg/ha
20002000
20012001 20022002
Percent of Soils Testing Medium or Percent of Soils Testing Medium or Lower in K in 2001Lower in K in 2001
North AmericaNorth America43%
Soil chloride levels in the Northern Soil chloride levels in the Northern Great PlainsGreat Plains
10,324 samples collected in 1995
AGVISE Laboratories (Northwood, ND)
52.5% < 30 lb/A52.5% < 30 lb/A
35%
30%44%
47%78%77%
82% 51%
64%
28%
14%
63
54%
89%61%
38%
19% 10%
13% 53%56%
54%55%
Fall 2002 Samples(0-24” samples)
MB
ND
SDMN
65%
Soil samples with chloride < 30 lb/aSoil samples with chloride < 30 lb/a
200 sample pairs from 17 counties collected from June to September, 1999
Oklahoma State Univ.
Cl in Oklahoma soilsCl in Oklahoma soils
Chloride removal by cropsChloride removal by crops
Crop Plant part Cl content
Alfalfa Shoot 7.6 lb/tonBarley Grain 0.024 lb/buWheat Grain 0.026 lb/buPotatoes Tubers 0.06 lb/cwt
Summary: Does Cl deserve my Summary: Does Cl deserve my attention?attention?
Where K fertilization is minimal In non-coastal areas Where fungal disease pressure is high For responsive crops: wheat, barley, corn,
sorghum For crops sensitive to toxicity growing where
soil accumulation is likely Where soil and plant analyses indicates low
levels or unusually high levels
It probably deserves more It probably deserves more attention than its gettingattention than its getting