soil changes during stockpiling and after reclamation at ... · 2009. 2010. 2011. 2012. 2013. 2014....

Soil changes during stockpiling and after reclamation at three Wyoming natural gas

production areas

Jay Norton and Calvin Strom University of Wyoming

2017 Joint Conference of the American Society of Mining and Reclamation

Mine Drainage Task Force Appalachian Regional Reforestation Initiative

Morgantown, West Virginia April 12, 2017

Soil Function in aridisols and aridic alfisols • A horizon: interface with atmosphere:

– OM accumulation and ELUVIATION; – loss of clays, solutes; – More OM, coarser texture, lower EC & pH

than other horizons; – Water infiltration & holding; nutrient cycling

(microbes) – Germination/establishment;

• B horizon: zone of accumulation of clays and solutes: ILLUVIATION – Less OM, finer texture, higher EC & pH – Water holding in finer texture

Salvage & reclamation procedures

One size fits all

A E Bt

Cr

Btn2

Btn1

Bk

sandy loam clay

Pre disturbance: ABSTON FINE, SMECTITIC, FRIGID USTIC NATRARGIDS

Scraping depth

Clay loam

After reclamation: ENTISOL

Topsoil

Subsoil

Clay loam

Loss of A horizon reduces already slim chances for germination & establishment • Lifeless: little SOM to support

microbial activity and nutrient cycling;

• Finer: inhibits water infiltration and facilitates evaporation;

• Drier: less OM and fine texture decrease plant-available water;

• Saline: EC > 4; osmotic potential and ion toxicity slow germination;

• Sodic: ESP > 15 disperses aggregates, exacerbating the above.

Pipelines + P&A + Active wells 29,683 Currently Producing Wells On File 121,626 Total Wells On File (DrillingEdge.com)

Great Divide and Green River Basins Objectives: determine short and longer-term effects of natural gas development and reclamation on soil quality across a precipitation gradient. Effects of topsoil depth on organic matter dynamics Aridisols and Entisols formed in saline and sodic marine shales.

11 inches

9 inches 7 inches

PLANT RESIDUE

STRUCTURAL

SOM

METABOLIC SOM

ACTIVE SOIL

C

SLOW SOIL

C

PASSIVE

SOM

Slow SOM

ACTIVE SOM

Soil Organic Matter Pools Active, or labile, SOM: Annual turnover Mineral N Mineralizable C& N dissolved organic C & N; Microbial C & N; light fraction C & N.

Slow, or protected, SOM:

Decades;

Same as labile, but protected from mineralization within soil structure.

Passive, or stabile, SOM:

Centuries to millennia;

Humus;

Mineral-associated C & N;

LOSSES: Harvest, CO2 & N2O emissions, erosion etc.

Pinedale Anticline Elevation: 2440 meters MATmax: 11°C MATmin: -6.6°C Fine-loamy, mixed, superactive, frigid Calcidic Haplustalfs MAP: 276 mm Annual CV: 26.5%

-30

-20

-10

0

10

20

30

0

10

20

30

40

50

60

70

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Tem

pera

ture

(C)

Prec

ipita

tion

(mm

)

-30

-20

-10

0

10

20

30

0

10

20

30

40

50

60

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Tem

pera

ture

(C)

Prec

ipita

tion

(mm

)

Total Precipitation

Max. Temperature

Min. Temperature

Jonah Field Elevation: 2140 meters MATmax: 11.9°C MATmin: -7.2°C Fine-loamy, mixed, superactive, frigid Calcidic Haplustalfs MAP: 232 mm Ann CV: 27%

Wamsutter/Great Divide Basin Elevation: 2065 meters MATmax: 13.2°C MATmin: -2.6°C Fine-loamy, mixed, superactive, frigid Typic Haplargids MAP: 180 mm Ann CV: 32%

-30

-20

-10

0

10

20

30

0

10

20

30

40

50

60

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Tem

pera

ture

(C)

Prec

ipita

tion

(mm

)

Three new well pads sampled at each field starting in 2009 (9 points composited) 1. Predisturbance; 2. Stockpile; 3. Respread; 4. 1 year later; 5. 7 years later.

Soil samples from 0-5, 5-20, and 20-30 cm

Stockpiles: Three points sampled to 250 cm

Data Collection

• Vegetation cover • Physical properties: bulk density, texture • Chemical properties: pH, EC • Biological properties (total and labile soil organic matter):

– Total soil organic carbon and nitrogen; – Mineral nitrogen; – Dissolved organic carbon and nitrogen; – Mineralizable organic carbon and nitrogen.

Jonah, 2011 Jonah, 2016

Anticline, 2011 Anticline, 2016

2009 2010 2011 2012 2013 2014 2015 2016

Sep-Nov

2009 2010 2011 2012 2013 2014 2015 2016

Sep-Nov

020406080

100120140160

2009 2010 2011 2012 2013 2014 2015 2016

Sep-Nov

Study Period Precipitation

050

100150200250300350400450

2009 2010 2011 2012 2013 2014 2015 2016

Prec

ipita

tion

(mm

)

Pinedale

2009 2010 2011 2012 2013 2014 2015 2016

Jonah

2009 2010 2011 2012 2013 2014 2015 2016

Wamsutter

0

50

100

150

200

250

0 100 200 300 400 500

Dept

h (c

m)

CO2-C mineralized (mg kg-1)

May

June

August

0

50

100

150

200

250

0 100 200 300 400 500

Dept

h (c

m)

CO2-C mineralized (mg kg-1)

0

50

100

150

200

250

0 200 400 600 800

Dept

h (c

m)

CO2-C mineralized (mg kg-1)

Mineralizable C in stockpiles, 2009 Pinedale Jonah Wamsutter

0

5

10

15

20

25

30

35

0 10 20 30Clay Content (%)

Wamsutter

0

5

10

15

20

25

30

35

0 10 20 30Clay Content (%)

Jonah

Reclaimed Undisturbed

0

5

10

15

20

25

30

35

0 10 20 30De

pth

(cm

) Clay Content (%)

Anticline

0

5

10

15

20

25

30

35

0 10 20 30Clay Content (%)

Wamsutter

0

5

10

15

20

25

30

35

0 10 20 30Clay Content (%)

Jonah

Undisturbed

0

5

10

15

20

25

30

35

0 10 20 30De

pth

(cm

) Clay Content (%)

Anticline

Reclaimed: Soil texture

0

5

10

15

20

25

30

35

0 10 20 30Clay Content (%)

Wamsutter

0

5

10

15

20

25

30

35

0 10 20 30Clay Content (%)

Jonah

Reclaimed Undisturbed

0

5

10

15

20

25

30

35

0 10 20 30De

pth

(cm

) Clay Content (%)

Anticline

Reclaimed: Soil texture

0

50

100

150

200

250

300

0

5

10

15

20

25

30

Predisturbance Stockpiled Reclaimed Reclaimed 1 yr

PMC

(mg

kg-1

)

PMN

and

Min

eral

N (m

g kg

-1)

Mineral N

PMN

PMC

Jonah

0-30 cm weighted averages

Disturbance Effects 1. Undisturbed: high labile SOM concentrations, low

mineral N concentrations (low net mineralization); 2. Pulse of labile and mineral nutrients after

disturbance truncated in cold storage in stockpile; 3. Pulse of mineralization at expense of PMC and N; 4. Loss of mineral N, labile OM begins to rebound.

0

100

200

300

400

500

600

0

10

20

30

40

50

60

Predisturbance Stockpiled Reclaimed Reclaimed 1 yr

PMC

(mg

kg-1

)

PMN

and

Min

eral

N (m

g kg

-1)

Anticline

0

50

100

150

200

250

300

0

5

10

15

20

25

30

Predisturbance Stockpiled Reclaimed Reclaimed 1 yr

PMC

(mg

kg-1

)

PMN

and

Min

eral

N (m

g kg

-1)

Mineral N

PMN

PMC

Jonah

050100150200250300350400450500

05

101520253035404550

Predisturbance Stockpiled Reclaimed Reclaimed 1 yr

PMC

(mg

kg-1

)

PMN

and

Min

eral

N (m

g kg

-1) Wamsutter

Disturbance Effects 0-30 cm weighted averages

Anticline: complicated by stockpile being moved at least twice.

Loss of labile C and N

0

5

10

15

20

25

30

35

Min

eral

Nitr

ogen

(mg

kg-1

)

All Well Fields

0

10

20

30

40

50

0

100

200

300

400

500

PMC

and

N (m

g kg

-1)

Anticline

0

5

10

15

20

25

0

50

100

150

200

250

PMC

and

N (m

g kg

-1)

Jonah

05101520253035404550

0

50

100

150

200

250

PMC

and

N (m

g kg

-1) Wamsutter

TOC TN % change

Anticline 72 88 Jonah -45 -197

Wamsutter 3.7 -1.7

Change: predisturbance to seven years after reclamation.

Recovery of SOM

0

0.05

0.1

0.15

0.2

0.25

0.0

0.5

1.0

1.5

2.0

2.5So

il O

rgan

ic C

arbo

n (%

)

Anticline

0

0.1

0.2

0.3

0.4

0.5

0.0

0.5

1.0

1.5

2.0

2.5

Soil

Org

anic

Car

bon

(%) Jonah

0

0.05

0.1

0.15

0.2

0.25

0.0

0.5

1.0

1.5

2.0

2.5

Soil

Org

anic

Car

bon

(%)

Wamsutter

Conclusions • Stockpiles in semiarid region may not be affected by depth, at least in the

short-term; • What about age?

• Compared with degraded reference sites, reclaimed sites seem to recover

or exceed original SOM levels within seven years; • Possibly due to increased herbaceous vegetation

• Potentially mineralizable carbon recovers more slowly;

• Possibly due to loss of soil structure, which protects labile SOM from mineralization, and continued accelerated mineralization, lack of woody species…

• Interest in reclamation research is as variable as annual rainfall.

Thanks to • Calvin Strom • Cally Driessen • Amber Mason • Jennifer Faulkner • Leann Naughton • Luke Driessen • Kristi Bear • Todd Loubsky • K.C. Harvey, Inc. • Gary Austen, BP America • Pete Guernsey, QEP Resources • Ralph Swift, Encana Exploration • UW School of Energy Resources • Wyoming Reclamation &

Restoration Center