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