Managing Water Quality Managing Water Quality in Growing Mediain Growing Media
Managing Water Quality Managing Water Quality in Growing Mediain Growing Media
David Wm. ReedDavid Wm. ReedDepartment of Horticultural SciencesDepartment of Horticultural Sciences
Texas A&M UniversityTexas A&M University
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Factors That Impact Water Quality in GrowingFactors That Impact Water Quality in Growing Media Media
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Factors That Impact Water Factors That Impact Water Quality in Growing MediaQuality in Growing Media
Factors That Impact Water Factors That Impact Water Quality in Growing MediaQuality in Growing Media
Irrigation Water QualityIrrigation Water Quality
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Irrigation Water QualityIrrigation Water QualityIrrigation Water QualityIrrigation Water Quality Chemical PropertiesChemical Properties
pHpH alkalinityalkalinity ECEC SARSAR
Individual Soluble SaltsIndividual Soluble Salts Water Treatment MethodsWater Treatment Methods
Growing Medium EC and pHGrowing Medium EC and pH
(from Lang 1996)(from Lang 1996)
SaturatedSaturated
PastePaste
1:21:2
DilutionDilution
PourPour
ThroughThrough
pHpH
All PlantsAll Plants 5.5-6.55.5-6.5 5.5-6.55.5-6.5 5.5-6.55.5-6.5
EC dS/mEC dS/m
Young PlantsYoung Plants 1-21-2 0.5-0.90.5-0.9
Established Established PlantsPlants
2-32-3 0.8-1.20.8-1.2 3-53-5
Irrigation Water Alkalinity LimitsIrrigation Water Alkalinity Limits Irrigation Water Alkalinity LimitsIrrigation Water Alkalinity Limits
Minimum MaximumMinimum Maximumppmppm meq/l meq/l ppmppm meq/lmeq/l
Plugs and/or seedlingsPlugs and/or seedlings 3838 0.750.75 6666 1.31.3
Small pots/shallow flatsSmall pots/shallow flats 3838 0.750.75 8686 1.71.7
4" to 5" pots/deep flats4" to 5" pots/deep flats 3838 0.750.75 106106 2.12.1
6” pots/long term crops6” pots/long term crops 6363 1.251.25 131131 2.62.6
(from Bailey 1996)(from Bailey 1996)
Irrigation Water Critical LimitsIrrigation Water Critical Limits
(from Biernbaum 1994)(from Biernbaum 1994)
MinimumMinimum MaximumMaximum
pHpH 5.55.5 7.07.0
EC (dS/m)EC (dS/m) 0.20.2 0.80.8
ppmppm
AlkalinityAlkalinity 4040 160160
CaCa 2525 7575
MgMg 1010 3030
SS 00 4040
NaNa 00 2020
ClCl 00 2020
FeFe 00 11
ZnZn 00 0.50.5
BB 00 0.10.1
CuCu 00 0.10.1
MoMo 00 0.10.1
FF 00 0.10.1
Plant Nutrient Requirements Supplied Plant Nutrient Requirements Supplied by Irrigation Waterby Irrigation Water
NutrientNutrient
Minimum ppmMinimum ppm
To Supply PlantTo Supply Plant
RequirementsRequirements
SS 20-30 ppm20-30 ppm
CaCa 40 ppm40 ppm
MgMg 20 ppm20 ppm
BB 0.3 ppm0.3 ppm
Sulfur Supplied by Irrigation WaterSulfur Supplied by Irrigation Water
(from Reddy 1996)(from Reddy 1996)20-30 ppm supplies most plant’s requirement20-30 ppm supplies most plant’s requirement
Irrigation Water QualityIrrigation Water QualityIrrigation Water QualityIrrigation Water Quality
Water Treatment MethodsWater Treatment Methods
Water Purification MethodsWater Purification Methods
(from Reed 1996)(from Reed 1996)
ReverseReverse
OsmosisOsmosis
WaterWater
SoftenerSoftener
AcidAcid
InjectionInjection
Aeration/Aeration/
OxidationOxidation
ActivatedActivated
Carbon/AlCarbon/Al
AlkalinityAlkalinity
(carbonates)(carbonates)XX XX
Total SaltsTotal Salts XX
SodiumSodium XX XX
ChlorideChloride XX XX
IronIron XX XX XX
BoronBoron XX
FluorideFluoride XX XX
ManganeseManganese XX XX XX
CopperCopper XX XX
CalciumCalcium XX XX
SulfateSulfate XX
Reverse Osmosis UnitReverse Osmosis UnitReverse Osmosis UnitReverse Osmosis Unit
Reverse Osmosis Water Purification To Decrease Salts
Reverse Osmosis Water Purification To Decrease Salts
Pretreatments:Pretreatments:
1) Polymer injection1) Polymer injection to coagulate due to high SDIto coagulate due to high SDI
2) Depth Filter2) Depth Filter to remove coagulated particlesto remove coagulated particles
3) Charcoal Filter3) Charcoal Filter to remove municipal chlorineto remove municipal chlorine
4) Ion Exchange4) Ion Exchange to remove residual polymerto remove residual polymer
Purification System:Purification System:
Reverse OsmosisReverse Osmosis using polyamide membranesusing polyamide membranes
(pH resistant, chlorine sensitive)(pH resistant, chlorine sensitive)
Production CapacityProduction Capacity
Purified Water Purified Water 5,760 gallons per day5,760 gallons per day
Blended Water (40/60)Blended Water (40/60) 14,400 gallons per day 14,400 gallons per day
Blend to EC ofBlend to EC of 0.75 dS/m (approx. 500 ppm)0.75 dS/m (approx. 500 ppm) (from Reed 1996)(from Reed 1996)
Reverse Osmosis Water Purification To Decrease Salts
Reverse Osmosis Water Purification To Decrease Salts
CostsCosts
Lease and ServiceLease and Service $900 per month$900 per month
Water (1.09/1,000)Water (1.09/1,000) $700 per month$700 per month
ElectricityElectricity $200 per month$200 per month
TotalTotal $1800 per month$1800 per month
Purified Water CostPurified Water Cost 1 cent per gallon1 cent per gallon
Blended Water CostsBlended Water Costs 0.4 cents per gallon0.4 cents per gallon
Production Space IrrigatedProduction Space Irrigated
80,000 to 135,000 square foot of 6-inch production space80,000 to 135,000 square foot of 6-inch production space
(at 12-20 oz/6”pot/day at 0.9 sq. ft. space/6”pot)(at 12-20 oz/6”pot/day at 0.9 sq. ft. space/6”pot)
Purified Water Used ForPurified Water Used For
Salt sensitive foliage plants and mist propagationSalt sensitive foliage plants and mist propagation (from Reed 1996)(from Reed 1996)
Acid InjectionAcid Injection80% Neutralization to Approx. pH 5.880% Neutralization to Approx. pH 5.8
Acid InjectionAcid Injection80% Neutralization to Approx. pH 5.880% Neutralization to Approx. pH 5.8
Fluid ounce of acid Fluid ounce of acid ppm ppm
per 1,000 of water,per 1,000 of water, per oz. perper oz. per
for each meqfor each meq 1,000 gal1,000 gal
AcidAcid of alkalinityof alkalinity waterwaterNitric (67%)Nitric (67%) 6.786.78 1.64 N1.64 N
Phosphoric (75%)Phosphoric (75%) 8.308.30 2.88 P2.88 P
Sulfuric (35%)Sulfuric (35%) 11.0011.00 1.14 S1.14 S
(from Bailey 1996)(from Bailey 1996)
Fertilizer ProgramFertilizer ProgramFertilizer ProgramFertilizer Program Soluble Liquid FeedSoluble Liquid Feed Granular IncorporationGranular Incorporation Controlled Release IncorporationControlled Release Incorporation
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
EC of Soluble Fertilizers & Water QualityEC of Soluble Fertilizers & Water Quality
(from Peterson 1996)(from Peterson 1996)
Fertility & Salt Stratification in the Root ZoneFertility & Salt Stratification in the Root ZoneSubirrigation – New Guinea Impatiens ‘Barbados’Subirrigation – New Guinea Impatiens ‘Barbados’
(from Kent & Reed 1996)(from Kent & Reed 1996)
Irrigation MethodIrrigation MethodIrrigation MethodIrrigation Method Top-Watering vs. SubirrigationTop-Watering vs. Subirrigation Vertical Stratification of SaltsVertical Stratification of Salts Evaporation from SurfaceEvaporation from Surface Leaching FractionLeaching Fraction
Factors That Impact Water Quality in Growing MediaFactors That Impact Water Quality in Growing Media
Vertical Stratification of Soluble SaltsVertical Stratification of Soluble Salts
Salt Stratification in the Root Zone with Different Salt Stratification in the Root Zone with Different Irrigation MethodsIrrigation Methods
(from Molitor, 1990, Warncke & Krauskopf 1983)(from Molitor, 1990, Warncke & Krauskopf 1983)
Evaporation from SurfaceEvaporation from Surface
Causes Vertical Stratification of SaltsCauses Vertical Stratification of Salts
(from Argo and Biernbaum 1995(from Argo and Biernbaum 1995Warncke & Krauskopf 1983)Warncke & Krauskopf 1983)
Effect of Evaporation on Salt StratificationEffect of Evaporation on Salt StratificationPoinsettia ‘Gutbier V-14 Glory’Poinsettia ‘Gutbier V-14 Glory’
Effect of Evaporation on Salt StratificationEffect of Evaporation on Salt StratificationPoinsettia ‘Gutbier V-14 Glory’Poinsettia ‘Gutbier V-14 Glory’
(from Argo and Biernbaum 1995(from Argo and Biernbaum 1995Warncke & Krauskopf 1983)Warncke & Krauskopf 1983)
Vertical Stratification of Soluble SaltsVertical Stratification of Soluble Salts
andand
Root DistributionRoot Distribution
Salt Stratification & Root DistributionSalt Stratification & Root Distribution
Spathiphyllum in subirrigationSpathiphyllum in subirrigation
(from Kent & Reed, unpubl; (from Kent & Reed, unpubl; Warncke & Krauskopf 1983)Warncke & Krauskopf 1983)
Track EC to MonitorTrack EC to Monitor Soluble Salt AccumulationSoluble Salt Accumulation Over FertilizationOver Fertilization Minimum Fertility LevelMinimum Fertility Level
Caution:Caution: DO NOT sample the top layer DO NOT sample the top layer
Graphical Tracking: ECGraphical Tracking: EC
Crop: ______________________
Leaching FractionLeaching Fraction
andand
Soluble Salt AccumulationSoluble Salt Accumulation
Leaching in Top-Watering Vs. SubirrigationLeaching in Top-Watering Vs. Subirrigation
Leaching Fraction in Top-WateringLeaching Fraction in Top-Watering
LF ~ 0.3-0.4LF ~ 0.3-0.4Low LFLow LF High LFHigh LF
LF LF EC ECww / (5(EC / (5(ECee(desired)(desired)-EC-ECww))))
Effect of Leaching Fraction on Medium ECEffect of Leaching Fraction on Medium EC
Poinsettia ‘V-14 Glory’Poinsettia ‘V-14 Glory’
(from Yelanich and Biernbaum 1993,(from Yelanich and Biernbaum 1993,Warncke & Krauskopf 1983)Warncke & Krauskopf 1983)
0
1
2
3
4
5
6
ECdS/msat.ext.
2 4 6 8 10 12 14 16
Week
0.55 LF0.55 LF
0.35 LF0.35 LF
0.15 LF0.15 LF
0 LF0 LF
Top Layer Salts and Wilting Upon IrrigationTop Layer Salts and Wilting Upon IrrigationEspecially Critical in SubirrigationEspecially Critical in Subirrigation
(from Todd & Reed 1998)(from Todd & Reed 1998)
Leaching & Salt Removal From MediaLeaching & Salt Removal From MediaNew Guinea Impatiens ‘Blazon’ in SubirrigationNew Guinea Impatiens ‘Blazon’ in Subirrigation
(from Todd & Reed 1998)(from Todd & Reed 1998)
1 2 3 4 5 6 0 2 4 6 8 10 14 180
5
10
15
20
ECdS/m
Times LeachedmM CaCl2 + NaCl
Determination of Determination of Soluble Salt Toxicity LimitsSoluble Salt Toxicity Limits
““Shoot Gun” ApproachShoot Gun” Approach
Plant Response to 24 Texas Water SourcesPlant Response to 24 Texas Water Sources
(from Kent & Reed unpubl)(from Kent & Reed unpubl)
1.11.1
1.01.0
1.21.2
0.40.40.20.20.50.5
0.10.10.50.50.80.8
0.10.1
0.90.9 0.30.3
0.80.8
0.70.70.30.3
0.20.20.50.5
Growth Versus EC with 24 Water SourcesGrowth Versus EC with 24 Water SourcesVinca ‘Apricot Delight’ Grown in SubirrigationVinca ‘Apricot Delight’ Grown in Subirrigation
(from Kent & Reed unpubl)(from Kent & Reed unpubl)
Growth Versus EC with 24 Water SourcesGrowth Versus EC with 24 Water SourcesVinca ‘Apricot Delight’ Grown in SubirrigationVinca ‘Apricot Delight’ Grown in Subirrigation
(from Kent & Reed unpubl)(from Kent & Reed unpubl)
Growth Versus EC with 24 Water SourcesGrowth Versus EC with 24 Water SourcesVinca ‘Apricot Delight’ Grown in SubirrigationVinca ‘Apricot Delight’ Grown in Subirrigation
(from Kent & Reed unpubl)(from Kent & Reed unpubl)
(from Kent & Reed unpubl)(from Kent & Reed unpubl)
Growth Versus Na + Cl with 24 Water SourcesGrowth Versus Na + Cl with 24 Water SourcesVinca ‘Apricot Delight’ Grown in SubirrigationVinca ‘Apricot Delight’ Grown in Subirrigation
Determination of Determination of Soluble Salt Toxicity LimitsSoluble Salt Toxicity Limits
Studies on Individual SaltsStudies on Individual Salts(cation + anion combinations)(cation + anion combinations)
Chrysanthemum
Rose 0 mM 2.5 mM
0 mM
5 mM
7.5 mM 10 mM
2.5 mM 5 mM
7.5 mM 10 mM
Toxicity Limits to Sodium BicarbonateToxicity Limits to Sodium Bicarbonate
(from Valdez, PhD)(from Valdez, PhD)
RoseRose MumMum VincaVincaHibiscus Hibiscus ‘Mango ‘Mango Breeze’Breeze’
Hibiscus Hibiscus
‘‘Bimini Bimini Breeze’Breeze’
SPAD SPAD Index Index
decreasedecreasePredicted mPredicted mMM NaHCONaHCO33
10%10% 0.80.8 3.23.2 6.06.0 2.12.1 4.24.2
20%20% 1.71.7 4.84.8 7.47.4 4.24.2 8.58.5
30%30% 2.82.8 6.16.1 8.48.4 6.36.3 12.712.7
40%40% 4.24.2 7.27.2 9.39.3 8.48.4 16.816.8
Predicted NaHCOPredicted NaHCO33 Toxicity Limit as a Toxicity Limit as aFunction of Chlorosis Function of Chlorosis
(from Valdez, PhD)(from Valdez, PhD)
Determination of Determination of Soluble Salt Toxicity LimitsSoluble Salt Toxicity Limits
Studies on Individual SaltsStudies on Individual Salts(cation + anion combinations)(cation + anion combinations)
Problem With This ApproachProblem With This ApproachDo not know if the effect is due to the Do not know if the effect is due to the
cation or the anioncation or the anion
Determination of Determination of Soluble Salt Toxicity LimitsSoluble Salt Toxicity Limits
Separation of Anion and Cation Separation of Anion and Cation Effects Using Mixture ExperimentsEffects Using Mixture Experiments
½:0:½
Y0:1:0
X1:0:0
Z0:0:1
½:½:0
0:½:½
2/3:1/6:1/6
1/6:2/3:1/6 1/6:1/6:2/3
1/3:1/3:1/3
Pure blends
Tertiary blends
Centroid
Binary blends
Mixture ExperimentMixture ExperimentDesignDesign
Rb+7.5mM
K+ 0 mM
Na+7.5mM Na+ 0 mM
2.5
3.5
4.5
5.5
Rb+ 0 mM
K+ 7.5mM
Mixture-Amount Experiments to Separate the
Na+ and HCO3- Effect in Sodium
Bicarbonate
Mixture-Amount Experiments to Separate the
Na+ and HCO3- Effect in Sodium
BicarbonateNa+ tox./K+ def.=-19%
HCO3- effect=-15%
Sh
oot
Dry
M
ass (
g)
(from Valdez, PhD)(from Valdez, PhD)
0 mM HCO30 mM HCO3
7.5 mM HCO37.5 mM HCO3
0.00 1.00
0.25 0.75
0.50 0.50
0.75 0.25
1.00 0.00
1.00
2.00
3.00
4.00
5.00
6.00
2.5 HCO3-
2.5 mM total binary 2.5 mM total binary mixturemixture
0 HCO3-
Proportion of K+ and Na+
Na+=-19%
HCO3-=-19%
Sh
oot
Dry
M
ass (
g)
Na+
K+
Binary Mixture Experiments to Separate the
Na+ and HCO3- Effect in Sodium
Bicarbonate
Binary Mixture Experiments to Separate the
Na+ and HCO3- Effect in Sodium
Bicarbonate
(from Valdez, PhD)(from Valdez, PhD)
Mixture-Amount Experiments To Separate Mixture-Amount Experiments To Separate Chloride, Bicarbonate and Sulfate EffectsChloride, Bicarbonate and Sulfate Effects
(from Kent & Reed unpubl)(from Kent & Reed unpubl)
Separation of Chloride, Bicarbonate and Sulfate Effects Separation of Chloride, Bicarbonate and Sulfate Effects with Mixture-Amount Experimentswith Mixture-Amount Experiments
30 meq/l30 meq/l 45 meq/l45 meq/l 60 meq/l60 meq/l
Vinca ‘Pacifica Red’ in SubirrigationVinca ‘Pacifica Red’ in Subirrigation
HCOHCO33 HCO3HCO3HCO3HCO3
ClCl ClCl ClClSOSO44 SOSO44
SOSO44
Cation = NaCation = Na Cation = NaCation = Na Cation = NaCation = Na
(from Kent & Reed unpubl)(from Kent & Reed unpubl)
Mixture-Amount Experiments To Separate Mixture-Amount Experiments To Separate Chloride, Bicarbonate and Sulfate EffectsChloride, Bicarbonate and Sulfate Effects
30 meq/l30 meq/l(1,700 to 2,500 ppm)(1,700 to 2,500 ppm)
45 meq/l45 meq/l(2,300 to 3,400 ppm)(2,300 to 3,400 ppm)
60 meq/l60 meq/l(2,800 to 4,400 ppm)(2,800 to 4,400 ppm)
Vinca ‘Pacifica Red’ in SubirrigationVinca ‘Pacifica Red’ in Subirrigation
HCOHCO33 HCO3HCO3HCO3HCO3
ClCl ClCl ClClSOSO44 SOSO44
SOSO44
Cation = NaCation = Na Cation = NaCation = Na Cation = NaCation = Na
(from Kent & Reed unpubl)(from Kent & Reed unpubl)
ThanksThanksThanksThanks
0
1
2
3
4
0 100 200 300 400
Soluble Fertilizer ppm N
EC
dS/
m20-20-2015-10-30
EC of Soluble Fertilizers & Water QualityEC of Soluble Fertilizers & Water Quality
Rb+7.5mM
K+ 0 mM
Na+7.5mM Na+ 0 mM
2.5
3.5
4.5
5.5
Rb+ 0 mM
K+ 7.5mM
HCO3- effect=-15%
Na+ tox./K+ def.=-19%
Separation of Sodium and Bicarbonate Effect Separation of Sodium and Bicarbonate Effect Using Mixture ExperimentsUsing Mixture Experiments
(from Valdez, (from Valdez, Ph.D. dissertation)Ph.D. dissertation)
ggshootshootmassmass
Leaching & Salt Removal From MediaLeaching & Salt Removal From MediaNew Guinea Impatiens ‘Illusion’ in SubirrigationNew Guinea Impatiens ‘Illusion’ in Subirrigation
(from Todd & Reed 1998)(from Todd & Reed 1998)
1 2 3 4 5 6 0 2 4 6 8 10 14 180
5
10
15
20
EC dS/m
Times Leached mM CaCl2 + NaCl