Effects of Saline-Sodic Water on Soil Chemical and Physical Properties Kim Hershberger

Effects of Saline-Sodic Water on Soil Chemical and Physical Properties

Kim Hershberger

My StudyMy Study

Assess the effects of modestly saline-sodic water on soil chemical and physical properties of selected soil materials.

Overall Goal-Determine the suitability of irrigating with modestly saline-sodic waters, while still maintaining the sustainability of the soil.

Two laboratory experiments which subjected soils of varying clay content to diverse wetting/drying regimes using two water qualities.

Irrigable Acreages within the Buffalo Irrigable Acreages within the Buffalo Rapids Irrigation DistrictRapids Irrigation District

Soil Series

Taxonomy Texture Acres

Cherry Fine-silty, mixed, frigid Typic Ustochrepts sicl 6052.4

Marias Fine, smectitic, frigid Chronic Haphsturts sic 3527.1

Spinekop Fine-loamy, mixed, superactive, frigid Aridic Haplustepts

sicl 3045.3

Trembles Coarse-loamy, mixed, calcareous, frigid Typic Ustifluvents

fsl/l 2640.8

Havre Fine-loamy, mixed calcareous frigid Ustic Torifluvents

sil/sicl 2157.8

Busby Coarse-loamy, mixed Borollic Camborthids fsl 2002.1

TEXTURAL CLASSES

1- Clay % 0-11% - Loamy Sand, Sandy Loam, Loam

2- Clay % 12-22% - Sandy Loam, Loam, Silt Loam

3- Clay % 23-33% - Loam, Clay Loam, Silty Clay Loam

4- Clay % 34+ - Silty Clay Loam, Silty Clay, Clay

Baseline Chemistry DataBaseline Chemistry Data

0

2

4

6

8

10

12

14

16

18

4 6 7 8 9 15 17 18 19 21 21 22 23 26 28 29 30 33 33 34 37 44 45 52 56

Ranked Clay %

Baseline EC, dS/m

Baseline SAR

Baseline ESP, %

Water Quality TargetsWater Quality Targets

POWDER RIVER

EC = 1.56 dS/m

SAR = 4.54

pH = 8.03

CBM (PRODUCT WATER)

EC = 3.12 dS/m

SAR = 13.09

pH = 8.22

Wetting RegimesWetting Regimes

1X Wet/Dry with P.R.1X Wet/Dry with CBM5X Wet/Dry with P.R.5X Wet/Dry with CBM5X Wet/Dry with P.R. followed by leaching

with 1 pore volume distilled water5X Wet/Dry with CBM followed by leaching

with 1 pore volume of distilled water

Study of Soil Chemical Study of Soil Chemical ResponsesResponses

Treatment effect on soil chemistry was evaluated by monitoring the resultant saturated paste extract EC and SAR and comparing results with baseline conditions.

Comparisons made by analyzing data based on their textural class.

MethodsMethods

Soil materials were saturated according to the water quality x wetting regime treatment combinations.

1X treatments-following wetting soils were oven dried.

5X treatments-intermediate drying cycles for 24 hours at 95 deg F; following fifth wetting soils were oven dried.

For 5X+d, after fifth drying to 95 deg. F, soils were placed on wire mesh racks where ~1 pore volume of D.I. water was poured on the surface of each sample. Leachate water was allowed to drain for 24 hrs. Following drainage period, soils were oven dried.

n Mean

EC (dS/m) +

Mean

SAR+

Textural Class

1 9 3.08 a 6.06 a

2 13 3.39 a 6.04 a

3 16 3.28 a 5.34 a

4 11 3.78 b 7.91 b

Resultant Mean Saturated Paste Extract EC and SAR for Textural Classes (across all treatments)

Water Quality Treatment

Mean EC (dS/m)

Mean SAR

Base 49 0.82 a 2.56 a

1X P.R. 49 1.51 b 5.94 b

1X CBM 49 2.46 c 3.92 b

5X P.R. 49 3.21 d 4.94 b

5X P+d 49 3.02 e 4.86 b

5X CBM 49 6.93 f 11.31 c

5X C+d 49 5.73 g 10.85 c

Resultant Mean Saturated Paste EC and SAR for Treatment Combinations (across all textures)

0

0.5

1

1.5

2

2.5

3

3.5

4EC

(dS/

m) (

satu

rate

d pa

ste

extr

act)

Baseline

1X Wet/Dry-P.R.

1X Wet/Dry-CBM

1 2 3 4

Textural Class

0

1

2

3

4

5

6

7

8

9

10

EC (d

S/m

) (sa

tura

ted

past

e ex

trac

t)Baseline

5X Wet/Dry-P.R.

5X Wet/Dry-CBM

1 2 3 4

Textural Class

0

2

4

6

8

10

12EC

(dS/

m) (

satu

rate

d pa

ste

extra

ct)

Baseline

5X Wet/Dry-P.R. + distilled

5X Wet/Dry-CBM + distilled

1 2 3 4

Textural Class

0

2

4

6

8

10

12

14

16

18

20SA

R (s

atur

ated

pas

te e

xtra

ct)

Baseline

1X Wet/Dry-P.R.

1X Wet/Dry-CBM

1 2 3 4

Textural Class

0

5

10

15

20

25SA

R (s

atur

ated

pas

te e

xtra

ct)

Baseline

5X Wet/Dry-P.R.

5X Wet/Dry-CBM

1 2 3 4

Textural Class

0

5

10

15

20

25

30SA

R (s

atur

ated

pas

te e

xtra

ct)

Baseline



1 2 3 4

Textural Class

0

5

10

15

20

25

30

35

0 5 10 15 20 25 30

SAR (soil solution)

ESP

% (s

oil)

Baseline

1X Wet/Dry-P.R.

1X Wet/Dry-CBM

5X Wet/Dry-CBM

5X Wet/Dry-CBM + Distilled

5X Wet/Dry-P.R.

5X Wet/Dry-P.R. + Distilled

ESP (%) = (1.18 x SAR) + 0.51R2 = 0.94

ESP = 15

SAR =12

0

5

10

15

20

25

30

0 2 4 6 8 10 12

EC (dS/m)

SA

R (

soil)

Baseline

1X Wet/Dry-P.R.

1X Wet/Dry-CBM

5X Wet/Dry-CBM

5X Wet/Dry-CBM + Distilled

5X Wet/Dry-P.R.

5X Wet/Dry-P.R. + Distilled

SAR = 1.46 (EC) + 1.29R2 = .54

No Reduction in Infiltration

Slight to Moderate Reduction in Infiltration

Severe Reduction in Infiltration

SAR = 12

EC = 3

Ayers and Westcot (1976)

Soil Chemistry ConclusionsSoil Chemistry Conclusions

1.Repeated irrigation with saline-sodic water will result in a general increase in the soil salinity and sodicity.

2.Repeated irrigation or dispersal of CBM product water to irrigable land is likely to result in elevated soil salinity levels substantially higher than published thresholds for some irrigated crops.

3. Soil solution salinity will equilibrate at an EC value approximately 2-3 times the EC of the applied water; soil solution SAR appears to equilibrate at a level comparable to the SAR of the applied water as long as leaching occurs.

4. Application of salt-free water following elevation of soil solution salinity and SAR through repeated wetting effectively reduced soil solution salinity while having little or no effect on sodicity.

5. The lowering impact of rainfall on EC and SAR is more predominant when salt concentrations are high, and in coarser-textured soils.

6. The greatest increases in EC and SAR upon wetting with either CBM or P.R. water were in coarser-textured soils.

7.In few instances of this study were soil solution salinity x sodicity combinations measured which exceed these thresholds following single wetting events. In essentially all instances where saline-sodic water was repeatably applied, the resulting soil solution salinity and sodicity were significantly elevated to levels in close proximity to the previously published EC x SAR standards.

8. Results of this study appear to be consistent with previously published reports of the relationship between exchangeable sodium percentage (ESP) and solution SAR, i.e., SAR = 0.8 x ESP (approximately). Utilizing an ESP threshold of 15, the majority of treated soil samples exceeding this value resulted from alternate wetting regimes with CBM product water followed by simulated rainfall.

Soil Physical Properties StudySoil Physical Properties Study

MethodsMethods Soil water retention was measured at 1/10 - 15 -bars of applied pressure. Water content was measured after soils had undergone treatment

combinations (same as the soil chemistry study treatments. For 1X treatments, soils were saturated for 24 hrs before pressure was

applied. For 5X treatments, soils were placed on wire racks for wet/dry cycles and

transferred to pressure plates for the final wetting period.

Methods cont.Methods cont.

5X+d-Same procedure as the 5X– Final wetting on the

plate consisted of DI application

Texture -1/10 bar -1/3 bar -1 bar -5 bar -15 bar

1 0.25 a 0.11 a 0.06 a 0.05 a 0.04 a

2 0.33 b 0.21 b 0.13 b 0.10 b 0.08 b

3 0.39 c 0.28 c 0.20 c 0.15 c 0.11 c

4 0.45 d 0.32 d 0.23 d 0.18 d 0.14 d

Mean Gravimetric Water Content at Applied Pressure Potentials for each Textural Class (across

all treatment combinations)

WQ Treatment -1/10 bar

-1/3 bar

-1 bar -5 bar -15 bar

1X P.R. 0.37 a 0.23 a 0.16 a 0.12 a 0.09 a

1X CBM 0.37 a 0.22 a 0.16 a 0.12 a 0.09 a

5X P.R. 0.35 b 0.23 a 0.14 b 0.12 a 0.09 a

5X P+d 0.35 b 0.23 a 0.16 a 0.12 a 0.09 a

5X CBM 0.35 b 0.23 a 0.15 c 0.12 a 0.09 a

5X C+d 0.35 b 0.23 a 0.16 a 0.12 a 0.09 a

Mean Gravimetric Water Content at Applied Pressure Potentials for each Treatment

Combination (across all textures)

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2Di

ffere

nce

in P

w fr

om B

asel

ine

(1X

P.R.

)g

H20/

g dr

y so

il1X Wet/Dry-CBM

5X Wet/Dry-PR


5X Wet/Dry-CBM


1/10 (-bar)

1 2 3 4

Textural Class

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2D

iffer

ence

in P

w fr

om B

asel

ine

(1X

P.R

.)g

H20

/g d

ry s

oil

1X Wet/Dry-CBM

5X Wet/Dry-P.R.


5X Wet/Dry-CBM


1/3 (-bar)

1 2 3 4

Textural Class

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20D

iffer

ence

in P

w fr

om B

asel

ine

(1X

P.R

.)g

H20

/ g d

ry s

oil

1X Wet/Dry-CBM

5X Wet/Dry-P.R.


5X Wet/Dry-CBM


1 (-bar)

1 2 3 4

Textural Class

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20D

iffer

ence

in P

w fr

om B

asel

ine

(1X

P.R

.) g

H20

/g d

ry s

oil

1X Wet/Dry-CBM

5X Wet/Dry-P.R.


5X Wet/Dry-CBM


5 (-bar)

1 2 3 4

Textural Class

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20Di

ffere

nce

in P

w fr

om B

asel

ine

(1X

P.R.

)g

H20/

g dr

y so

il1X Wet/Dry-CBM

5X Wet/Dry-P.R.


5X Wet/Dry-CBM


15 (-bar)

1 2 3 4

Textural Class

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 2 4 6 8 10 12 14

Matric Potential (h) (-bars)

Wate

r C

on

ten

t (

g H

20/g

dry

so

il)

1X Wet/Dry-P.R.

1X Wet/Dry-CBM

5X Wet/Dry-P.R.


5X Wet/Dry-CBM


Textural Class #1

Textural Class #2

0

0.1

0.2

0.3

0.4

0.5

0.6

0 2 4 6 8 10 12 14

Matric Potential (h) (- bars)

Wate

r C

on

ten

t (g

H 20/g

dry

so

il)

1X Wet/Dry-P.R.

1X Wet/Dry-CBM

5X Wet/Dry-P.R.


5X Wet/Dry-CBM


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 5 10 15


Wate

r C

on

ten

t (g

H20/g

dry

so

il)

1X Wet/Dry-P.R.

1X Wet/Dry-CBM

5X Wet/Dry-P.R.


5X Wet/Dry-CBM


Textural Class #4

Textural Class #3

0

0.1

0.2

0.3

0.4

0.5

0.6

0 5 10 15


Wat

er C

on

ten

t (g

H20/

g d

ry

soil)

1X Wet/Dry-P.R.

1X Wet/Dry-CBM

5X Wet/Dry-P.R.


5X Wet/Dry-CBM


Soil Physical Properties Soil Physical Properties ConclusionsConclusions

1. Water content associated with matric potential differed significantly due to predominant soil texture at all matric potentials investigated in this study.

2. Significant differences in water holding capacity of coarser-textured soils occur due to water quality treatment more often at greater matric potentials. In finer-textured soils differences in water holding capacity due to water quality treatment are more likely to occur at lower potentials.

3. Significant changes in water holding capacity due to water quality treatment are only on the order of 0.02-0.04 g H20/g dry soil. The change

reflected a decrease in water holding capacity in textural classes 1 & 2 and an increase in water holding capacity in textural class 3.

4. Reductions in water retention in coarser-textured soils are attributable to the loss of large pore spaces.

5. The addition of saline-sodic water had the greatest effect on soil physical properties when the soil is near saturation. Changes in water holding capacity are likely to have non-discernible impact on irrigation suitability.

6. Successive wetting/drying cycles can cause aggregate coalescence and the loss of interaggregate porosity; this appeared to occur more often in the coarser-textured soils.

7. Although statistically significant differences were detected among water quality treatments, differences were not large enough to have a significant ecological impact.

8. CBM product water applied at these levels did not have a consistent significant impact on soil physical properties, i.e., water-holding capacity.

AcknowledgementsAcknowledgements

Committee: Dr. Jim Bauder (chair), Dr. Douglas Dollhopf, Dr. Jon Wraith

Funding: Prairie County Conservation District, Buffalo Rapids Irrigation District, Department of Energy

Bernard Schaff, Susan Winking, and Bauder Students

ACKNOWLEDGEMENTS

Documents

Effects of Saline-Sodic Water on Soil Chemical and Physical Properties Kim Hershberger