USDA
United States
Department of
Agriculture
Forest
Service
Ogden UT 84401
United States
invironmsntal Protection
Industrial Environmental Rassarch EPA-600 779-068
Lsfeoratory February 1979
Cincinnati OH 45238
crtd D®velop3n@fit
(fievegetating
Processed ©el
Shale and O©i
Spoils on
Semi-Arici] Lands
Interim Report
Interagency
Energy/Environment
R&D Program
Report
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the
effort funded under the 17-agency Federal Energy/Environment Research-and
Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the rapid development of domestic
energy supplies in an environmentally-compatible manner by providing the nec-
essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants and their health and ecological
effects; assessments of, and development of, control technologies for energy
systems; and integrated assessments of a wide range of energy-related environ-
mental issues.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/7-79-068
February 1979
REVEGETATING PROCESSED OIL SHALE AND COAL
SPOILS ON SEMI-ARID LANDS
Interim Report
by
Nell C. Frischknecht and Robert B. Ferguson
Intermountain Forest and P.ange Experiment Station
Provo, Utah 84601
IAG No. DE-E764
Project Officer
Ronald D. Hill
Resource Extraction and Handling Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U. S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory - Cincinnati, U.S. Environmental Protection Agency, and approved
for publication. Approval does not signify that the contents necessarily
reflect the views and policies of the U.S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorse-
ment or recommendation for use.
ii
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FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our environment and even on our
health often require that new and increasingly more efficient pollution
control methods be used. The Industrial Environmental Research Laboratory-
Cincinnati (lERL-Ci) assists in developing and demonstrating new and improved
methodologies that will meet these needs both efficiently and economically.
The increased demand for energy within the United States will ultimately
lead to an increased utilization of coal and oil shale in the semi-arid
regions of our country. Coal production from the Western states has already
increased significantly. In order to meet the current needs of those charged
with revegetating the land disturbed by surface mining, an interim report
has been prepared on the results of Forest Service studies instead of waiting
until the research is completed several years from now. The results of this
work should provide the reclamation specialist of a mining company or control
agency with the tools to assist him in the establishment of a good ground
cover to minimize the environmental problem from surface mining.
For further information contact Neil Frischknecht or Robert Ferguson,
Intermountain Forest and Range Experiment Station, Provo, Utah or the
Extraction Technology Branch of the Resource Extraction and Handling Division.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
iii
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ABSTRACT
Early revegetation studies sponsored by Colony Development Operation
(1965-1973) showed that selected grasses and other plants can be successfully
established on TOSCO II processed oil shale following leaching 62 percent
of the soluble salts with 48 to 60 inches (1.2 to 1.5 m> of water.
Forest Service revegetation studies on TOSCO II processed shale (begin-
ning in 1976) at Sand Wash, eastern Utah, within the salt desert shrub zone
and at Davis Gulch, western Colorado, in the upper mountain brush zone,
involved the use of amendments on processed shale without leaching salts.
At Sand Wash, seven species of the Chenopodiaceae family were far
superior to other species on processed shale with or without supplementary
water or a covering of soil. Where at least 1 foot (30 cm) of soil covered
processed shale, an additional eight species showed good survival. Drip
irrigation greatly benefited overall plant establishment on processed
shale, whereas little improvement was seen from the same amount of water
where depth of soil over processed shale was 1 foot (30 cm) or more.
At Davis Gulch, a covering of 8 to 12 inches (20 to 30 cm) of topsoil
over processed shale greatly increased survival and growth of container-
grown plants compared to a 2- to 3-inch (5 to 7.5 cm) covering of broken
rock fragments or a cover of barley straw crimped into the processed shale.
Through the third growing season at least, plant survival and growth on
gravelly subsoil from the site was about equal to that where topsoil covered
processed shale.
On a simulated mining tract at the Alton coal field, southern Utah,
grass hay rotovated 8 inches (20 cm) deep into the soil increased seedling
survival. Where several overburden materials were tested as growing media
for plants, sandy loams and loam topsoils gave best results while a dark-
colored carbonaceous shale material (clay loam) lying immediately above
the coal seam gave better results than the poorest topsoil (silty clay).
These studies showed that where fall planting of seeds on arid and
semi-arid sites often fails, spring planting of container-grown plants can
ensure successful revegetation of disposal areas.
iv
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CONTENTS
Foreword ill
Abstract iv
vi
Acknowledgments vii
1. PROCESSED OIL SHALE 1
Introduction ....... . 1
Review of Present Knowledge 2
Disposal of Processed Shale 2
Earlier Revegetation Studies on Processed Oil Shale 3
Initial Field Study 3
Chemical and Physical Properties Affecting Plant Growth . 3
Effects of Amendments 4
Forest Service Studies in Utah and Colorado 6
Effects of Drip Irrigation and Depth of Soil Over Processed
Shale 6
Comparison of Fall-Planted Seeds with Spring-Planted Container-
Grown Plants 11
Effects of Soil Amendments on Growth of Selected Shrubs and
Forbs in the Mountain Brush Zone of Western Colorado .... 12
Microclimatic Factors of Processed Oil Shale Disposal Piles . 18
Conclusions 20
Recommendations 22
2. SURFACE MINED COAL SPOILS 23
Introduction 23
Review of Present Knowledge 24
Use of Topsoil 24
Soil Amendments 25
Mulching 26
Fertilization 27
Seeding and Planting Methods 28
Selecting Species for Revegetation 29
Availability of Material 30
Equipment for "Revegetation 30
Forest Service Studies at the Alton Coal Field, Utah 32
Revegetation Techniques on Disturbed Overburden from Simulated
Mining ....... 32
Effects of Organic Amendments on Growth of Selected Grasses . 35
Adaptability of Selected Grasses and Shrubs on Different
Profile materials ........ • 37
Establishment and Longevity of Several Plant Species on Various
Topsoils and Shaley Overburden 38
Conclusions and Recommendations ........ 40
References 41
Appendix 44
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FIGURES
Number Page
1 Cross-section diagram of experimental site ..... 7
2 Differential plant survival on both drip-irrigated and
non-irrigated plots .... 7
3 Single plant of Mediterranean camphorfume 9
4 (A) Fourwing saltbush plant... (B) Prostrate summer cypress . . 10
5 (A) Experimental plots at Davis Gulch...second growing
season... (B) ...third growing season 17
6 Topsoil stockpiled in windrows .... 32
7 A good cover of grasses, forbs, and shrubs in second growing
season 34
TABLES
1 Percent plant survival after 1 year by site treatment and
topographical aspect 13
2 Percent plant survival after second growing season...
Davis Gulch 14
3 Comparative height of two species on four growing media .... 15
4 Percent mortality by plant species and site treatment...
Davis Gulch 16
5 Mean temperatures of processed oil shale and native soil .... 19
6 Seed mixture used on larger study areas at Alton coal field . . 33
7 Mean maximum number of plants/square foot (0.09 m2) for soil
amendments 35
8 Mean maximum number of plants/square foot (0.09 m2) for 10
selected grasses 36
vi
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ACKNOWLEDGMENTS
Studies on revegetation of processed oil shale reported herein were
conducted in cooperation with The Oil Shale Company (TOSCO) which provided
the processed shale for experiments. Studies at the Alton coal field were
conducted in cooperation with the Bureau of Land Management, USDI (EMRIA),
and Utah International Inc. Cooperators provided lands on which to conduct
field studies, financial assistance, and technical review of study plans.
The assistance of TOSCO employees, Edward B. Baker, Joe M. Merino, and
David L. Craig, in the establishment and maintenance of the study areas at
Davis Gulch and Sand Wash is gratefully acknowledged.
David B. Crouch, Senior Environmental Engineer, and Robert W. Poyser,
Environmental Engineer, Utah International Inc., participated in planning
one of the studies on the Alton coal field.
Special thanks are given to Larry G. Sip, Resource Area Manager, Bureau
of Land Management, Kanab, Utah, for assistance with various details pertain-
ing to the field work at the Alton site.
vii
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SECTION 1
PROCESSED OIL SHALE
INTRODUCTION
Oil shale lands occur primarily in the Green River geological formation
in Utah, Colorado, and Wyoming. The area involved encompasses some 25,000
square miles (64,750 km2) or 16 million acres (6.5 million ha). Of this,
approximately 17,000 square miles (44,030 km2) or 11 million acres (4.5
million ha) is believed to contain shale suitable for commercial development.
This is the world's largest known area of oil reserves, estimated to contain
some 600 billion barrels of oil. These shales underlie a variety of topo-
graphical areas including high plateaus, isolated mesas, and broad basins
where average annual precipitation ranges from an estimated 20 inches (51 cm)
on the high plateaus to 6 inches (15 cm) or less in the broad basins.
Approximately 72 percent of the oil shale deposits occur on federally
owned lands, where an estimated 80 percent of the oil shale reserves
lie. Also, each of the three States involved, Utah in particular, own
sizeable areas of oil shale lands; other areas are owned privately, mainly
by oil companies. These lands are presently used for grazing of domestic
livestock, wildlife habitat, hunting, recreation, oil and gas, and other
extractive mineral operations.
Over the years, several patented processes have been developed for
extracting oil from shale, including both in situ retorting and underground
mining followed by surface retorting. The latter process recovers greater
amounts of oil, but disposal of the processed shale is an environmental
concern. Disposal embankments will require revegetation. Processed shale
from the TOSCO II retorting process was used in the revegetation
studies described in this report.
The generally accepted practices and theories for revegetating western
ranges are inapplicable for establishing plants on raw, processed oil shale,
which has been heated up to 900°F (482°C) or higher in the oil extraction
process. High levels of salinity, low organic matter, and low levels of
available nutrients in processed shale require amendments before successful
revegetation can take place. Aridity of many potential disposal sites adds
greatly to the problem.
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Early research on processed oil shale in Colorado (described later)
shows that successful revegetation with grasses is possible following heavy
leaching of salts, but subsequent capillary rise of salt to the surface
presents another problem. The discovery of ways to revegetate spoils using
a minimum amount of water in addition to breaking the capillary rise of
salts is important. An especially difficult problem is the development
of methods to ensure continuity of vegetative cover following drought which
is common in the arid regions involved. Rehabilitation measures on disturbed
areas and spoil materials must enhance the environment along with establish-
ing vegetative cover.
REVIEW OF PRESENT KNOWLEDGE
Disposal of Processed Shale
At present, surface disposal is the most efficient method of handling
processed shale (Merino and Crookston 1977). Studies on disposal embank-
ments of TOSCO II processed shale by Heley and Terrell (1974) for Colony
Development Operation revealed that compaction by haul rigs probably would
be adequate for stability of the major portion of disposed materials. This
provides a bulk density of around 85 pounds per cubic foot (1,362 kg/m2).
The moisture requirement for placement and compaction at that bulk density
is approximately 13 percent. At that moisture level, dust can be easily
controlled, and the grid roller providing optimum compaction leaves a packed
surface which retains precipitation and resists dusting. Surface wetting
causes a crust to form on the material to aid in longer-term dust prevention.
Other findings are: (1) that a segmented wheel, self-propelled machine
provides maximum compaction and lowest overall operation cost; (2) an 18-
inch- (46 cm) thick layer should be used in all areas; (3) a spreading and
leveling blade should be used prior to any compaction; (4) frontal slopes
of disposal piles should not exceed 15 degrees (preferably 4:1) to allow
equipment operation and revegetation; and (5) standing water should not be
permitted on working surfaces.
Laboratory tests conducted by Dames and Moore (1974) for the Colony
Development Operation showed that processed shale lost significant strength
upon saturation. Considering that a small portion of the frontal face of
disposal piles could become saturated at various periods during the year,
the investigators recommended that benched slopes of 25 percent (4 horizontal
to 1 vertical) be used rather than the proposed slopes of 33 percent (3:1).
They also recommended that slopes be benched at every 50-foot- (15 m) height
interval and that the width of benches be approximately 20 feet (6 m).
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Earlier Revegetation Studies on Processed Oil Shale
Several investigators studied revegetation of processed (spent) oil
shale for Colony Development Operation during the period 1965-1973. Brief
summaries of those studies follow:
Initial Field Study—
A field study in 1965 described by Haberman (1973) involved growing
four grasses on five different media: (1) soil, (2) shale ash, (3) processed
shale, (4) mixture of shale ash with soil, and (5) mixture of processed shale
with soil. Shale ash was left after spent shale had been ignited at higher
temperatures to utilize energy from remaining carbon. The processed shale
and mixtures of processed shale with soil proved better growing media for
plants than plain shale ash alone or in a mixture. Tall wheatgrass1 produced
more growth than other plant species tested.
Chemical and Physical Properties Affecting Plant Growth—
Schmell and McCaslin (1973) found that spent shales from the TOSCO •
and Bureau of Mines retorts were highly saline, highly alkaline, low in
available P and N, and questionable in available K. In the greenhouse,
tall wheatgrass and Russian wildrye showed poor growth in spent shale, and
mixtures of up to 50 percent shale and 50 percent soil produced far less
plant growth than would be acceptable in the field. Following leaching of
about 62 percent of the soluble salts from spent shale, tall wheatgrass
grew well when both nitrogen and phosphorous were applied, but additional
potassium and micronutrients did not affect plant yields. Leaching of 62
percent of the soluble salts reduced the conductivity of saturation extract
below 4 mmhos/cm. The dark-colored, crushed, spent shale in a glasshouse
reached temperatures of 140° to 150°F (60°C to 66°C) at about 1/2-inch
(1.3 cm) depth, which can be lethal for germinating seeds.
Studies by Berg (1973) which supplement and confirm the above findings
are summarized as follows:
1. The texture of TOSCO II processed shale is a silt loam having a
moderate water infiltration rate unless compaction occurs, in
which case the infiltration rate would be slow.
2. The pH of samples taken from plot studies was within the range
suitable for plant growth.
1 Scientific names and common names are shown in the appendix.
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3. Soluble salt content was very high in processed shale and also
from some samples taken from plot and greenhouse studies.
4. Nitrogen available to plants as NOa and NHi, was very low in non-
fertilized processed shale, suggesting that vegetation grown in
processed shale would probably require long-term nitrogen fertil-
ization. Phosphorous levels were low and potassium levels were
moderate to low.
5. Zinc, iron, copper, and manganese in processed shale appeared to
be adequate for plant growth.
6. Boron may occur in toxic quantities in processed shale, but there
was no evidence of toxicity in field plots. Boron appears to be
leachable which would reduce its toxicity.
7. The sodium adsorption ratio decreases with leaching. Without
leaching, the sodium content is high in processed shale.
Effects of Amendments—
From extensive greenhouse studies conducted in 1968, 1969, and 1970,
Schaal (1973) found that seed germination occurred in spent shale, but
growth was greatly retarded and plants died before reaching maturity. Saw-
dust and peat amendments produced limited improved growth; however, nitric
acid (1 percent) promoted good growth. Phosphoric acid produced limited
improved plant growth, but plant color was pale green. A weekly addition
of a complete fertilizer promoted growth equal to plants in normal soil. In
these studies plants were watered to prevent wilting and the excess water
drained out through cracks in the bottom of wooden flats.
In 1968-1969, field experiments by Schaal (1973) at Colony Develop-
ment Operations' semi-works site in Parachute Creek, Colorado, showed that
leached processed shale, mulched with peat and sawdust and fertilized,
provided an excellent medium for growth of tall wheatgrass and Russian
wildrye. Engelmann spruce, juniper, large- and small-leaf cottonwood,
Chinese elm, golden willow, sagebrush, and penstemon all grew well in this
medium; however, the longevity of these plant species is not known.
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On plots in the middle fork of Parachute Creek, Berg (1973) observed
no differences in plant growth from sawdust amendments on processed shale at
rates of 10, 20, and 40 tons per acre (22, 44, and 88 metric tons/ha). Also,
no differences in plant growth were noted from the six following mulch treat-
ments: (1) none, (2) unprocessed crushed oil shale, (3) talus composed of
flat rock fragments 1 inch (2.5 cm) and less in diameter, (4) jute mesh, (5)
barley straw, and (6) talus, over talus that had been mixed 3 inches (7.5 cm)
deep into spent shale. The better-than-expected growth in the unmulched plot
was attributed to careful and frequent sprinkling with water during germina-
tion and seedling establishment along with partial shade and a northeast
exposure. Water application was judged to be between 47 and 60 inches (119
and 152 cm) during the 16-month period, May 1971 through September 1972.
This would allow between 7 and 20 inches (18 and 51 cm) of water for leaching
of salts above the potential evapotransspiration of 40 inches (101 cm) for
the same period.
Following leaching, in September 1972, the saturation extract conduc-
tivity of the processed shale profile showed the following range: 1.9
mmhos/cm at 0-4 inches (0-10 cm), 4.1 mmhos/cm at 8-12 inches (20-30 cm),
7.5 mmhos/cm at 12-16 inches (30-41 cm) and 11.0 mmhos/cm at 20-25 inches
(51-63 cm). By comparison, a bulk sample of unleached processed shale has
a saturation extract conductivity of 13.0 mmhos/cm.
In this study. Berg observed that two native wheatgrasses (western,
streambank) and three introduced wheatgrasses (fairway, pubescent, tall)
along with sweetclover, made excellent early growth after planting in 1971.
Indian ricegrass, sand dropseed, hard fescue, and Russian wildrye were
somewhat slower establishing and all except Indian ricegrass formed good
ground cover the following years. Thirty bare-root transplants each of
Rocky Mountain juniper and skunkbush sumac showed 71 and 72 percent survival,
respectively, during the first year; however, considerable mouse damage
occurred in 1972, which was attributed to the excelsior mat that was used
as mulch.
In a cooperative study at Parachute Creek between the Soil Conservation
Service and Colony Development Operation, Merkel (1973) observed very little
plant survival on pure processed shale, mixed success on 50/50 processed
shale-soil mixture, and excellent survival and growth on native soil. The
study involved planting seeds|of 11 grasses and 4 shrubs, plus transplants
of 12 shrub species. All plots were mulched with excelsior material and
fertilized with 459 pounds per acre (515 kg/ha) of 34-0-0 fertilizer plus
540 pounds per acre (605 kg/ha) of 0-45-0 fertilizer. Water was applied to
transplants at the July planting and once per week thereafter until August
rains came.
Three shrubs exhibited 60 percent or better survival on processed
shale: New Mexico locust, New Mexico forestiera, and Russian olive.
Exhibiting somewhat lower survival (40 percent) on processed shale were
fourwing saltbush and skunkbush sumac.
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FOREST SERVICE STUDIES IN UTAH AND COLORADO
Greenhouse studies on TOSCO II processed shale were begun by the
Intermountain Forest and Range Experiment Station in the winter of 1975-1976,
followed by field studies in the spring of 1976. A greenhouse bioassay
study of five nonmine waste amendments on processed shale showed that
sewage sludge had significantly greater beneficial effects on seed germina-
ation and plant growth than wood fiber, straw, sugar beet pulp, or cow
manure (Williams and Packer 1977). Sewage sludge apparently ties up the
sodium salts in spent shale and was found to be a beneficial amendment
even in the absence of leaching with water. Three of the other four amend-
ments (wood fiber, straw, and cow manure) aided plant survival and growth,
especially when combined with leaching. Sugar beet pulp was not beneficial,
nor was the addition of sulfur. As expected, seed germination and plant
growth were both improved as a result of leaching spent shale with water.
Field studies were established at two main locations: (1) Sand Wash,
in the salt desert shrub vegetation type, southwest of Vernal, Utah, and
(2) Davis Gulch, at the head of Parachute Creek, on the Roan Plateau in
Western Colorado.
Effects of Drip Irrigation and Depth of Soil Over Processed Shale
The first study at Sand Wash, Utah, had the following objectives:
(1) to evaluate effects of soil depth over processed shale, (2) to evaluate
effects of drip irrigation, and (3) to evaluate response of individual
species.
In late April 1976, approximately 375 tons (340 metric tons) of TOSCO II
processed oil shale were transported by truck from Colony Development
Operations at Parachute Creek, Colorado, to the Sand Wash area approximately
50 miles (80 km) southwest of Vernal, Utah, for revegetation trials. (The
Sand Wash site is on land owned by the State of Utah and leased to TOSCO,
with whom the Intermountain Station has a cooperative agreement).
At the experimental site, spent shale was spread and compacted approxi-
mately 2-1/2 feet (76 cm) deep in a V-shaped ravine that had been modified
for this purpose. This area was 40 feet (12 m) wide and 75 feet (23 m)
long. Soil previously removed in shaping the area was spread over the
center portion of the spent shale in the form of a double-edged wedge so
that replaced soil varied in depth from zero at the two outside edges to
approximately 3 feet (91 cm) deep in the center (Figure 1).
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Original
ground level
Figure 1. Cross-section diagram of experimental site depicting cut in native
soil (C), processed oil shale fill (B&C), and native soil fill (A).
Treatments on strips 5 feet (150 cm) wide and 75 feet (23 m) long
extending from both outside edges toward the center of the 40-foot (12 m)
area are depicted in Figure 1, as follows: (1) spent shale with sewage
sludge amendment and straw mulch; (2) spent shale covered with 0 to 1 foot
(0 to 30 cm) of replaced soil; (3) spent shale covered with 1 to 2 feet
(30 to 60 cm) of replaced soil; and (4) spent shale covered with 2 to 3 feet
(60 to 90 cm) of replaced soil.
The sewage sludge was spread on the two outside 5-foot (150 cm) strips
of processed shale to a depth of 1 to 3 inches (2.5 to 7.5 cm) and roto-
tilled to a depth of about 4 inches (10 cm).
On May 4 to 5, 1976, 20 species of container-grown plants were planted
in plots 5 feet (150 cm) long and 2-1/2 feet (75 cm) wide with four replica-
tions on each treatment. A randomized-block, split-plot design was used,
with one-half of the plots to receive supplementary water by drip irrigation
(Figure 2). Plots contained two rows of four plants each. Rows were spaced
15 inches (37.5 cm) apart, as were the four plants within rows.
Figure 2. Differential plant survival on both drip-irrigated and non
irrigated plots at end of the second growing season at Sand Wash.
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Prior to establishing the drip irrigation system in 1976, approximately
1 quart (0.95 liter) of water was added to each plant in all four blocks
(replications) at the time of planting on May 4 and again on May 18 and
June 2. Initial water was necessary to aid establishment of all plants
because site preparation in the spring did not allow for undisturbed on-site
accumulation of winter moisture. Thereafter, water was added to only two
blocks (replications) through emitters that allowed each plant to receive
water at the rate of 1 gallon (3.8 liters) per hour, as follows:
1976
July 7: 20 minutes; July 30: 15 minutes; August 15: 30 minutes;
September 3: 15 minutes; September 20: 30 minutes.
1977
May 5: 15 minutes; September 23: 15 minutes.
1978
No supplementary water.
The amount of precipitation received at the study site from the date
of planting through December 1976 is unknown. At Ouray, 12 miles (19 km)
to the northwest, total precipitation for the period was 1.95 inches (5 cm).
Precipitation during 1977 was 6.36 inches (16.2 cm) on this site. Precipita-
tion for the first 6 months of 1978 was 2.34 inches (5.9 cm).
In the spring of 1977, plants that received supplementary water (two
blocks) by drip irrigation the previous summer, were making new growth
earlier than plants not irrigated (two blocks).
Most plants showed good survival over winter on both irrigated and
nonirrigated plots, with the following exceptions: narrowleaf low rabbit-
brush, inland saltgrass, and Swainsonpea showed heavy mortality on non-
irrigated plots; cattle saltbush showed heavy mortality on both irrigated
and nonirrigated plots; big saltbush and blue saltbush showed heavy winter
mortality on irrigated plots, and mortality continued over summer. The
higher winter mortality for two species on irrigated plots suggests that
the supplementary water in the summer of 1976 did not allow these plants
to harden against frost, which is similar in effect to not hardening against
drought.
By the end of the second growing season (October 1977-), five native
shrub species and two introduced species were thriving under all conditions
ranging from processed shale without a soil covering to soil covering 0 to
3 feet (0 to 0.91 m) deep over processed shale. The endemics included
Gardner saltbush, broadscale saltbush, Bonneville saltbush, short-winged
saltbush, and fourwing saltbush. The introduced species were Mediterranean
camphorfume and prostrate summer cypress. Survival on processed oil shale
having no soil covering was slightly higher on irrigated plots, but where
soil covered the shale, survival was as good on nonirrigated as on irrigated
plots. Plants were generally taller on drip-irrigated plots.
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A second group of eight species showed very poor survival on the
processed shale itself, but varying success where soil covered shale,
depending upon the depth of covering. Three of the eight species ''winter-
fat, plumed whitesage, and inland saltgrass) showed good survival on plots
having some covering of soil over spent shale. Height growth increased
with soil depth, at least to the 1-foot (30 cm) depth. For the two shrubs,
survival was as good on nonirrigated plots as on irrigated plots. However,
saltgrass showed much better survival on irrigated plots under all condition;
of soil covering.
Five species showing little or no survival where the soil covering
was less than 1 foot (30 cm) thick over spent shale included: black
sagebrush, pygmy sagebrush, narrowleaf low rabbitbrush, scarlet globe-
mallow, and Swainsonpea. Where soil covering was at least 1 foot (30 cm)
thick, survival of these species was as good on nonirrigated plots as on
irrigated plots. (Seed of the first four species in this group came from
the Desert Experimental Range where annual precipitation averaged 6.8
inches (17.3 cm). Swainsonpea is an introduced legume from Russia.)
At the end of the 1977 growing season, most plants of Mediterranean
camphorfume and scarlet globemallow had been eaten by cottontail rabbits
entering the area where water had washed a small hole under the fence.
Fourwing saltbush also showed some damage caused by rabbits. One plant of
Mediterranean camphorfume (Figure 3) that was not grazed by rabbits grew to
a height of 26 inches (66 cm).
Figure 3. Single plant of Mediterranean camphorfume is 26 inches high
on a plot where soil is 2 feet deep over processed shale (other
plants of this species were browsed by rabbits).
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Exceptionally good growth of several species occurred in the second
growing season (1977) where runoff water from a high intensity summer storm
ponded along the edge of the processed shale plot. Flower stalks of pros-
trate summer cypress grew to 56 inches (142 cm) high and fourwing saltbush
to 32 inches (81 cm) (Figure A).
Figure 4. (A) Fourwing saltbush plant on irrigated processed shale grew to
a height of 32 inches (81 cm) in second growing season.
(B) Prostrate summer cypress is tallest species with Bonneville
saltbush to left and Gardner saltbush to right.
10
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Comparison of Fall-Planted Seeds with Spring-Planted Container-Grown Plants
The second study at Sand Wash had the following objectives:
(1) To evaluate response of fall-planted seeds and spring-planted
container-grown plants of the same species;
(2) To evaluate differences in types of replaced overburden; and
(3) To evaluate differences in growth and development of the various
species.
In late September 1976, an additional 475 tons (431 metric tons) of
processed shale were transported by truck from the Colony Development site
in Parachute Creek, Colorado, to a second experimental site at Sand Wash.
Results from the planting of container-grown stock in the first study had
shown best results from soil-covered processed shale. Therefore, the top
8 to 12 inches (20 to 30 cm) of soil from an area 50 feet (15 m) wide and 100
feet (30 m) long at the end of a small basin was stockpiled, and the area
was leveled for placement of the processed shale. The processed shale was
spread over the area to a depth of approximately 30 inches (76 cm). Washed
gravel about 1 inch (2.5 cm) in size was spread to a depth of 6 inches
(15 cm) over half of the area covered by processed shale. This in turn
was covered with 1 foot (30 cm) of native soil. Native soil was spread
over the other half of the processed shale to a depth of 18 inches
(46 cm).
On December 14, 1976, seeds of 25 shrubs were planted in single rows
and replicated four times for comparison with container-grown plants of the
same species grown in the greenhouse. Plots were 5 feet (1.5 m) wide and 10
feet (3 m) long for accommodating one row of fall-planted seed and one row
of container-grown plants. Container-grown plants of 25 species grown in
the greenhouse since January 1977 were planted on the new study site at
Sand Wash, May 3, 1977. Rows and plants within rows were spaced 30 inches
(76 cm) apart. This is twice the distance between plants in the study
established on processed shale at Sand Wash in early May 1976.
Because of drought in the winter of 1976-1977, only sparse germination
resulted from seeds sown the previous fall. When counts were made in
May 1977, 18 of the 25 species seeded showed some seedlings present, and
14 of this number showed some surviving plants at the end of the 1977
growing season.
11
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In contrast to low survival of plants from seed, survival was excellent
for nearly all container-grown plants put out May 3, 1977. Supplementary
water was added to these plants on two occasions, but most pronounced growth
occurred in the center of the experimental area where runoff water had
puddled from high intensity storms. In the puddled area, some plants grew
as high as 24 inches (61 cm) in the first growing season. One plant that
came from seed of a natural hybrid between fourwing saltbush and Castle
Valley "clover" grew to a height of 20 inches (51 cm) with a crown spread
of 30 inches (76 cm). Results showed that where supplementary water was
available, plants made excellent growth in the area, even in the first
growing season.
Effects of Soil Amendments on Growth of Selected Shrubs and Forbs
in the Mountain Brush Zone of Western Colorado
In May 1976, approximately 400 tons (363 metric tons) of TOSCO II spent
oil shale, stockpiled a year earlier for research purposes, were spread
through a small basin on the Roan Plateau above Parachute Creek, Colorado.
Eleven species of container-grown shrubs and forbs were planted on three
different exposures (north, south, and level), on four types of soil material
as follows:
1. Compacted processed oil shale, 2-1/2 feet (0.76 m) deep, covered
with 6 to 10 inches (15 to 25 cm) of native topsoil;
2. Compacted processed oil shale, 2-1/2 feet (0.76 m) deep, covered
with 1 to 4 inches (2.5 to 10 cm) of rock fragments obtained at
the study site;
3. Compacted prpcessed oil shale, 2-1/2 feet (0.76 m) deep, with
barley straw tilled into the top 6 inches (15 cm) at the rate of
2 tons per acre (0.73 metric tons/ha);
4. Three feet (91 cm) of subsoil material only.
Mortality occurred among some species during the first 90 days after
planting, a portion of which was caused by rodents prior to construction of
a rodentproof fence. Replacement plantings were made in September 1976
where planting stock was available.
By October 1976, overall survival of the initial planting was 78
percent on the topsoil-covered plots, 69 percent on subsoil, 59 percent on
rock fragment-covered plots, and 27 percent on straw-amended shale plots.
Plant survival on three different exposures was not widely different: 61
percent on the level, 56 percent on the south exposure, and 57 percent on
the north exposure.
12
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By the beginning of the second growing season (May 1977), the effects
of soil amendments and topographical exposure on plant survival were begin-
ning to show (Table 1). Data in Table 1 include the replacement plantings
of September 1976.
TABLE 1. PERCENT PLANT SURVIVAL AFTER 1 YEAR,
BY SITE TREATMENT AND TOPOGRAPHICAL ASPECT
Treatment
Topsoil
Rock mulch
Straw amendment
Subsoil only
Aspect mean
North
79
62
35
76
63
Aspect
Level
89
69
38
74
67
South Treatment Mean
79
53
36
76
60
82
61
36
75
During the first week in June 1977, container-grown plants of
prostrate summer cypress, Utah sweetvetch, rubber rabbitbrush, green
ephedra, and fourwing saltbush were used to replace losses suffered by
those species through the end of May. In addition, big sagebrush was
used to replace mountain mahogany on all plots, and red elder was used
to partially replace the losses of blueberry elder.
By the end of September 1977, 64 percent of the surviving plants
(including all surviving serviceberry and snowberry) had completed two
growing seasons. The remaining plants had survived one growing season.
Considering the overall percent survival over all exposures, the following
six species were most successful: (in descending order) big sagebrush,
fourwing saltbush, Siberian peashrub, rubber rabbitbrush, green ephedra,
and prostrate summer cypress (Table 2). All had survival percentages
greater than 60 percent. However, big sagebrush had only been established
for one growing season.
13
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TABLE 2. PERCENT PLANT SURVIVAL AFTER SECOND GROWING SEASON BY SPECIES,
SITE TREATMENT, AND ASPECT (DAVIS GULCH. COLORADO)
Topsoil-
covered
shale
Species
Saskatoon serviceberry
Big sagebrush
Fourwing saltbush
Siberian peashrub
True mountainmahogany
Rubber rabbitbrush
Green ephedra
Utah sweetvetch
Prostrate summer cypress
Tatarian honeysuckle
Blueberry elder
Mountain snowberry
Total survival
Mean
N1
50
100
91
90
0
91
69
62
100
100
83
80
79
L2
80
89
100
100
10
80
75
57
83
100
90
30
76
76
S3
20
100
100
100
0
70
100
56
71
100
40
80
73
N
0
100
100
100
0
91
80
62
62
30
17
30
61
Rock-
mulched
shale
L
0
100
100
100
0
100
100
62
83
17
31
70
66
61
S
60
100
91
100
0
71
82
57
100
25
0
10
58
N
0
90
71
80
0
47
41
50
38
0
0
0
37
Straw-
amended
shale
L
0
70
62
75
0
40
39
0
50
0
0
0
30
33
S
0
90
71
19
0
53
80
7
83
0
8
0
32
Subsoil
N
np"
90
100
100
0
np
100
100
62
90
31
40
73
L
np
100
91
90
0
100
100
100
50
91
36
40
77
76
S
np
100
100
100
0
100
83
100
62
77
60
0
78
Total
Survival
25
94
87
83
2
73
75
48
66
50
28
32
'N = North exposure
2L = Level
3S = South exposure
"*np = Species not planted on this plot
-------
Only minor differences in plant suvival were apparent on the three
exposures—the more mesophytic species such as serviceberry, honeysuckle,
elderberry, and snowberry suffering greatest mortality on the south-
facing slope.
In terms of plant vigor and growth rate, all plant species have grown
best on the topsoil-covered and subsoil plots. Only fourwing saltbush
and prostrate summer cypress have grown well on the processed oil shale
in the absence of a soil covering. Even so, these two species have little
more than half the height growth on the shale plot as on topsoil or subsoil
plots, as shown in Table 3.
TABLE 3. COMPARATIVE HEIGHT OF TWO SPECIES ON FOUR GROWING MEDIA
Subsoil
Topsoil-
covered
shale
Rock-
mulched
shale
Straw-
amended
shale
Inches Cm
Fourwing saltbush 38 (97)
Prostrate summer cypress 27 (69)
Inches Cm Inches Cm Inches Cm
36 (91) 26 (66) 19 (48)
24 (61) 15 (38) 13 (33)
Raindrop splash on processed shale having no covering gives small plants
a black color which would appear to reduce photosynthesis. Plants of all
species were smallest where there was no covering over processed shale.
15
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During the second winter (1977-1978), some mortality occurred among
all species except serviceberry, fourwing saltbush, and true mountain-
mahogany (though only one plant of the latter species had survived to
August 27, 1977) (Table 4). Increased growth through the early part of
the third growing season is depicted in Figure 5.
TABLE 4. PERCENT MORTALITY BY PLANT SPECIES AND SITE TREATMENT,
BETWEEN SEPTEMBER 1977 AND JUNE 1978 (DAVIS GULCH, COLORADO)
Serviceberry
Big sagebrush
Fourwing saltbush
Siberian peashrub
Mountainmahogany
Rubber rabbitbrush
Green ephedra
Utah sweetvetch
Prostrate summer cypress
Tatarian honeysuckle
Blueberry elder
Snowberry
Topsoil
covered
shale
0
4
0
0
0
4
4
7
0
0
4
10
Rock
mulched
shale
0
0
0
3
*
0
4
14
0
12
0
0
Straw
amended
shale
*
28
0
8
*
14
36
50
21
*
0
0
Subsoil
np
3
0
0
*
0
0
7
27
0
0
25
* = No surviving plants, 9/77
np = Species not planted on this plot
16
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Figure 5. (A) Experimental plots at Davis Gulch in western Colorado at end
of second growing season.
(B) Experimental plots at end of third growing season.
Treatment strips, left to right: (1) topsoil over processed shale;
(2) rock mulch over processed shale; (3) straw rotovated in processed
shale; and (4) subsoil only.
17
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Microclimatic Factors of Processed Oil Shale Disposal Piles
Initial data retrieval in this study began in May 1977, at Sand
Wash (Uintah County, Utah) and in late August 1977, at Davis Gulch
(Garfield County, Colorado). The primary objectives of the study are
to quantify microclimatic factors at these potential disposal sites and
to compare the microclimate of exposed processed oil shale with that of
disturbed soil.
At both sites, data on soil and air temperatures and precipitation
are being recorded by automatic data logging systems.2 At the Sand Wash
site, information is being obtained on relative humidity, wind speed,
and wind direction. At both study sites, data on soil moisture content
are monitored periodically through the use of thermocouple psychrometers.
The data logging systems are designed to read all sensors at hourly
intervals. The automatic data logging system at Sand Wash has functioned
well and minor maintenance and repairs have been readily accomplished
due to year-around accessibility of the study site. However, at Davis
Gulch, a heavy winter snowpack forced the discontinuation of data gathering
for a 6-month period during the winter of 1977-1978. The system was
reactivated on May 31, 1978.
A preliminary summary for the month of August 1977, at Sand Wash,
illustrates differences that may occur between the temperature of processed
oil shale and disturbed native soil for different depths (Table 5).
2A11 data obtained so far at both study sites have been stored on magnetic
tape but have not yet been evaluated.
18
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TABLE 5. MEAN TEMPERATURES OF PROCESSED SHALE AND NATIVE SOIL
AT VARIOUS SOIL DEPTHS FOR AUGUST 1977
Mean Min. (°C)
Processed Native
shale soil
3/4"
4"
8"
16"
32"
depth
depth
depth
depth
depth
9.4
27.8
22.8
20.0
16.7
9.4
19.4
25.0
22.8
18.3
Mean (°C)
Processed
shale
27.8
34.4
25.0
20.6
17.2
Native
soil
22.8
26.1
27.2
23.3
19.4
Mean Max. (°C)
Processed Native
shale soil
54.4 44.1
40.6 36.1
26.7 28.9
21.1 23.9
17.8 20.0
The highest temperature recorded at the 3/4-inch depth during the
month was 66.7°C on processed oil shale, compared to 49.4°C on soil.
Processed oil shale absorbed more heat than native soil in the upper 4
inches (10 cm), but from 8 inches (20 cm) to 32 inches (81 cm) native soil
was 2° to 3°C warmer than processed shale. Soil profile temperatures are
undoubtedly related to soil moisture content, and future analyses of soil
temperatures will consider this relationship.
19
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CONCLUSIONS
On a revegetation test site at Sand Wash in the salt desert shrub
zone of eastern Utah, seven shrub species belonging to the Chenopodiaceae
family were superior to other plant species on unleached processed oil
shale. The superior species included five endemic saltbushes (Gardner,
broadscale, Bonneville, short-winged, fourwing) and two introduced
species (Mediterranean camphorfume and prostrate summer cypress).
Two other chenopods (winterfat, plumed whitesage) and inland salt-
grass exhibited very low survival on processed oil shale itself, but
high survival on plots having some covering of soil over processed
shale; their height growth increased with depth of soil covering, at
least to the 1-foot (30 cm) depth.
Five species showing little or no survival where the soil covering
was less than 1 foot (30 cm) thick over processed shale included black
sagebrush, pygmy sagebrush, narrowleaf low rabbitbrush, scarlet globe-
mallow, and Swainsonpea. Three shrubs failing to survive winter temper-
atures on this site included big saltbush, cattle saltbush, and blue
saltbush.
Supplementary water from a drip-irrigation system was most benefi-
cial on processed oil shale and least beneficial where 1 foot (30 cm) or
more of soil covered processed shale. (Drip-irrigated plots received
approximately 1 liter of water per plant on five different occasions in
the first growing season, twice in the second growing season, and none
in the third season.) In the second growing season, the processed shale
plots on the edges of the test site received additional supplementary
water as surface runoff from adjacent slopes, which appeared to enhance
plant growth.
On a second site at Sand Wash, transplanting container-grown seedlings
in May 1977 proved more successful than planting seeds of the same species
the previous fall. Although replanting seeds in the fall of 1977 resulted
in good seedling stands in 1978, it can be expected that good survival
from fall seeding will occur only in years when winter and spring moisture
is above average. Spring planting of container-grown plants can ensure
successful establishment of shrub species.
20
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In the mountain brush zone of western Colorado (Davis Gulch) a covering
of topsoil approximately 1 foot (30 cm) thick was superior to other amend-
ments on processed oil shale. Eleven of 12 species tested showed good
survival and growth on this treatment.
Where barley straw was used as an amendment on processed oil shale,
only fourwing saltbush and prostrate summer cypress showed high survival.
Even so, their height growth was only about half that where topsoil covered
the shale or where plants were grown on a gravelly loam subsoil from the
site.
A covering of 2 to 3 inches (5 to 7.5 cm) of broken rock fragments over
processed shale was superior to the barley straw amendment with respect to
plant survival and growth, but inferior to topsoil or subsoil.
Preliminary results from studies of microclimate showed that processed
shale absorbed more heat in the surface 4 inches (10 cm) than native soil,
but native soil was 2°C to 3°C warmer than processed shale at depths of 8
to 32 inches (20 to 80 cm). Cooler temperatures in processed shale below
the 8-inch (20 cm) depth appeared related to higher moisture content. In
late summer, temperatures at 3/4 inch (2 cm) deep averaged 17°C higher in
processed oil shale than in native soil.
21
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RECOMMENDATIONS
Disposal embankments of processed oil shale should be covered with
1 foot (30 cm) or more of local topsoil which has shown good capability
for supporting vegetation. Use of topsoil increases the number of species
adapted for revegetating disposal embankments and greatly reduces the need
for fertilizers.
Several native saltbushes and two introduced Chenopodiaceae species
that showed excellent performance in these studies should be considered
for use in revegetating processed oil shale disposal embankments in the
arid salt desert shrub zone. Grasses that should be considered for use
in that zone include four native species (Indian ricegrass, galleta, blue
grama, alkali sacaton) and two introduced grasses (crested wheatgrass,
Russian wildrye). Galleta, blue grama, and alkali sacaton are warm-season
grasses that require adequate summer moisture for successful establishment.
In the more mesic mountain brush zone, the Chenopodiaceae and other
shrubs that performed well in these studies should be considered for re-
vegetating processed oil shale disposal areas that have been covered with
1 foot (30 cm) or more of topsoil. Native grasses that should be con-
sidered for use in the mountain brush zone include: beardless bluebunch,
streambank, thickspike, and western wheatgrasses, and Great Basin wildrye;
introduced grasses include smooth brome, fairway, intermediate, tall, and
pubescent wheatgrasses.
Use of container-grown plants on arid and semi—arid sites can ensure
successful revegetation of disposal areas where fall planting of seeds
has failed. One liter or more of water per plant should be applied at the
time of planting and as needed during the first growing season.
Whereas supplementary water might not be required beyond the first
growing season for plant survival, additional moisture stored in the
processed shale underlying a covering layer of topsoil would enhance plant
growth. By leaving the surface of disposal areas on arid sites slightly
lower than the surrounding terrain, moderate amounts of runoff water from
adjacent areas can be stored in the processed shale. Surface configurations
such as contour furrowing and/or pitting should be employed on disposal
areas to increase water infiltration and prevent runoff and erosion.
22
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SECTION 2
SURFACE-MINED COAL SPOILS
INTRODUCTION
Increased need for coal to supply the Nation's energy requirements
will lead to strip mining of coal deposits in several western states.
The restoration of vegetative cover on strip mined lands is imperative.
This section discusses known revegetation techniques for coal mine spoils
in the Western United States and includes new research from Utah.
Lands occupied by Utah's coal fields where strip mining is most likely
to occur are semi-arid or arid areas where average annual precipitation
ranges from 7 to 17 inches (18 to 43 cm). Vegetation presently occupying
these areas varies from the juniper-pinyon type, dominating the Alton
coal field in Kane County, to the salt desert shrub type in the Emery-
Carbon coal fields. A wide variety of soil types is present from sand
to heavy clays. Soils are often poorly developed and badly eroded.
Organic matter content and plant nutrients are low. Most soil and mine
spoil material has a basic pH.
The evapotranspiration demand is very high throughout the growing
season and is intensified by periods of high winds. In addition, much
of the precipitation is ineffective in replenishing soil moisture due to
surface runoff or diminutive amounts of less than 0.25 inches (0.6 cm)
per event. Moreover, the extreme variability in the occurrence of
rainfall and winter snows makes any seeding or planting program risky
without supplementary water to aid plant establishment.
23
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REVIEW OF PRESENT KNOWLEDGE
Use of Topsoil
In most cases, that portion of the coal overburden brought to the
surface during mining operations is less suitable for plant establishment
and growth than the stripped topsoil material. Clays and shales brought
to the surface from depths of up to 100 feet (30 m) are often fine textured
and are more saline, more sodic, and have higher pH values than topsoil
layers. As pointed out by Packer and Aldon (1978), the physical and
chemical properties of spoils that discourage good plant growth can usually
be circumvented or improved. Two basic approaches have been used to treat
mine spoils for better plant growth: cover undesirable spoils with suitable
soil materials, or apply amendments designed to alter the properties of the
spoils.
A number of advantages accrue when topsoil material is stockpiled
and spread on top of mine overburden. The population of important soil-
building microorganisms may be enhanced by the spreading of topsoil, as
discussed by Cundell (1977). Studies conducted at the Northern Great
Plains Research Center, Agricultural Research Service, and the North
Dakota Agricultural Experiment Station (1975) indicated that a topsoil
covering of as little as 2 inches (5 cm) appeared to produce benefits
greatly out of proportion to the amount of soil material used. Water
infiltration was increased, surface runoff and erosion was reduced, and
plant survival and growth were enhanced. After five seasons of growth,
a fair stand of desirable cool-season grasses existed. Farmer et al.
(1974) found that topdressing of mine overburden at the Decker Coal
Mine in Montana appeared to be a highly desirable revegetation practice.
Even in semi-arid and arid regions, poorly developed topsoil material
can be expected to have better fertility than raw spoils.
One disadvantage in the use of topsoil, in addition to the expense,
may be the presence of weed seeds. Beauchamp et al. (1975) found that
the top 2 inches (5 cm) of topsoil from three different vegetative types
(sagebrush-grass, saltbush, and greasewood) in Wyoming contained sufficient
seed to revegetate the area with more than the original density. However,
it was noted that the quality of the newly established vegetation would
be seriously altered, since most of the species were those normally
found in secondary succession. In arid environments, it would be desirable
to eliminate competition from annual weeds in order to give the seeded
perennial species as much soil moisture as possible.
24
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Soil Amendments
The use of chemical and/or organic amendments on strip mine spoils
may be necessary when spoils are high in exchangeable sodium, low in water
infiltration capacity, and deficient in plant nutrients. The sodium ad-
sorption ratio may be decreased in the upper levels of sodic mine spoils
through the application of gypsum or sulfur. Sodic spoil materials can also
be chemically reclaimed by using soluble calcium salts such as calcium
chloride and calcium nitrate; however, such treatment would require a source
of irrigation water and would be expensive. Also, the incorporation of
organic amendments into soil or overburden material will often enhance estab-
lishment and growth of plants. The greatest obstacle to the use of organic
amendments is the high cost of transportation from source of supply to the
mine site. Nearly all areas suitable for the strip mining of coal in Utah
are a considerable distance from large population centers where organic amend-
ments such as sewage sludge or municipal refuse could be obtained. Other
amendment materials such as hay, straw, and composted sawmill refuse are more
readily available, though often expensive to purchase and transport in large
quantities.
Sanks and Amirtharajah (1976) tested combinations of pulverized munici-
pal refuse, sewage sludge, and clay overburden as growing media for grass.
The clay overburden was obtained from a stockpile at the Big Sky Mine in
Montana. The study was conducted in a greenhouse, where the root zone was
continually kept moist. All clay mixtures of municipal refuse, digested
sewage sludge, and combinations of refuse and sludge produced 4 to 6 times
as much growth on a dry weight basis as did unfertilized clay. They also
found, in subsequent studies, that grass growth was better in fertilized
topsoil than from mixtures of clay overburden and solid waste, but that
mixtures of clay and/or solid waste produced many times as much growth as
unfertilized topsoil. These studies, although conducted under greenhouse
conditions, show that organic material can improve the physical and chemical
properties of mine spoils and perhaps of many topsoil materials.
Some organic soil amendments can, on the other hand, be harmful to plant
establishment. In a greenhouse test using mountain rye and adding bark to
topsoil and spoil material, the effect of the added bark was negligible on
emergence, and leaf length and ovendry weights were depressed (Aldon et al.
1975). Another laboratory study (Aldon and Springfield 1973) showed that
manure, sawdust, bark, and straw did not affect the emergence and early
growth of mountain rye and fourwing saltbush on 3-year-old mine spoils.
25
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Mulching
The use of surface mulches as an aid to establishing vegetation has
long been practiced. Some types of mulch, though undoubtedly beneficial,
would most likely prove too expensive to obtain and apply. Gravel, broken
rock, plastic, and treated paper are examples of effective but often costly
materials.
Organic mulches may conserve moisture, reduce temperature, prevent
erosion, help control competition from certain weeds by reducing light, and
supply organic acids and essential plant nutrients. Materials such as straw,
hay, and sawdust can be spread with a blower and held in place with asphalt
emulsion. On gentle terrain, mulching material can be tacked to the soil
with a crimper or sheepsfoot roller. Wood fiber can be applied with a hydro-
mulcher.
Hodder et al. (1970) found that a straw mulch consisting of about 0.75
to 1 ton per acre (1,700 to 2,200 kg/ha) tacked down with about 300 gallons
per acre (2,800 liters/ha) of asphalt emulsion is an effective mulching
treatment on coal mine spoils.
Investigations in New Mexico have also shown the advantages of using
mulch for establishing perennial species. Springfield (1972) found that the
most effective mulch was straw or a white petroleum resin. These materials
reduced moisture losses and lowered midafternoon soil temperatures during
the periods of seed germination and seedling emergence. Gould et al. (1975),
however, felt that mulching spoil material may have been detrimental to estab-
lishment of native range plants because of competition resulting from grain
and weed species in mulching material.
Any mulching technique should be tailored to suit specific conditions.
Excessive mulch can be harmful by intercepting precipitation, which is then
lost to evaporation, or by preventing optimum seed germination and seedling
emergence.
26
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Fertilization
Fertilization of strip mine spoils with inorganic fertilizers will
undoubtedly improve the chances for revegetation success, and in some
cases will be a necessity. Inorganic fertilizers will not, however,
guarantee success if spoil properties are exceptionally poor, such as
those that are high in exchangeable sodium.
Howard et al. (1977) found that the addition of nitrogen at 60 pounds
per acre (67 kg N/ha) or phosphorus at 60 pounds per acre (67 kg P/ha) to
mine overburden materials from the Wyodak and Seminoe coal mines and the
Utah International Uranium Mine in Wyoming, resulted in significantly
greater yields of alfalfa and thickspike wheatgrass than from unfertilized
overburden. These investigators also found that some shrub species responded
to fertilization while others did not. From these experiments and our own
past experience, it is apparent that many shrub and tree species can be
established without fertilization.
Studies at the Rosebud Mine near Colstrip, Montana, reported by
Willmuth and DePuit (1977) also show that inorganic fertilizers can
greatly enhance the growth of seeded grasses on mine spoils. They
found, however, that legumes responded negatively to fertilization
above certain levels and durations. Multiple year fertilization at low
levels proved more beneficial than single season fertilization at higher
levels in terms of perennial grass production.
As pointed out by Packer and Aldon (1978), the degree of dependence
that established vegetation on mine spoils has on continued fertilization
is not known. Long range nutrient requirements of plant communities on
mine spoils still must be determined.
The work of Williams and Aldon (1978), and Aldon (1975) has con-
clusively shown that the survival and growth of numerous shrub species
can be increased if steps are taken to ensure that the growing medium
contains endomycorrhizal fungi. Research on this aspect of revegetating
near-sterile soil material is in its infancy. As successful techniques
are developed for inoculating seedlings, revegetation success should
improve.
27
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Seeding and Planting Methods
Packer and Aldon (1978) have reviewed methods of seeding and planting
on coal mine spoils in the semi-arid and arid portions of the western
United States. In semi-arid areas where much of the annual precipitation
is received as autumn rain and winter snow, the usual practice is to seed
in late autumn and plant nursery stock in early spring. Late fall seedings
are best when mixtures of grasses, forbs, and shrubs are used because the
winter period provides stratification of the seed. However, when only
grasses are used, early spring seeding often appears advisable. Willmuth
and DePuit (1977) found this to be true in their studies at Colstrip,
Montana.
In the arid regions of New Mexico, the planting of fourwing saltbush
nursery stock can be successfully accomplished in late July and early
August when summer storms produce 0.4 inches (10mm) or more of precipita-
tion at each occurrence (Aldon 1973). Most likely other adapted shrubs
can be similarly established in regions where summer storms provide much
of the annual precipitation. The coal fields of southern Utah fit this
description.
The choice of whether to drill or to broadcast seed will depend upon
the specific conditions at each site. When soil materials have settled
or have been compacted, drilling is advisable. Drilled seed is mostly
covered with soil, providing for more satisfactory germinating conditions.
When the soil material surface is still loose and rough, such as immediately
after grading, broadcasting may be successful. Broadcasting is also
appropriate on steep, rough terrain where mechanized equipment is not
operable.
Drilling of seed is not compatible with seedbed preparation methods
such as pitting or gouging. The drilling operation would destroy the
depressions that are made to catch rainfall and to decrease surface
runoff. Following this type of seedbed treatment, direct seeding should
be done immediately, especially before appreciable rainfall occurs.
The establishment of shrubs and trees is desirable in some revegeta-
tion programs, especially where wildlife habitat restoration is important.
Shrub and tree seedlings are difficult to establish by direct seeding in
arid regions. Seeding shrubs in a mixture with perennial grasses imposes
stress of competition for soil moisture, and many shrubs are not good
competitors. Woody species can be established more reliably by planting
bare-root or container-grown nursery stock. Many species survive better
when container-grown seedlings are used, but some are established equally
well as bare-root stock. The key to successful planting of woody species
is to use high quality stock and plant properly. Adapted species can
usually be established if planted when soil moisture is plentiful or when
supplementary watering can be provided during the first growing season.
28
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Selecting Species for Revegetation
Selection of plant species for revegetating mine spoil areas will
depend primarily on what species are adapted to the local soils and
environment. Of secondary importance is the desired plant composition,
which depends on the use planned for the land. Determining what plants
can be grown on a specific mining area is a basic prerequisite of any
revegetation plan.
In semi-arid shortgrass prairie regions, the best native species
to seed include western wheatgrass, blue grama, sideoats grama, and
buffalograss. Adapted introduced grasses include smooth brome, crested
wheatgrass, and Russian wildrye. Native shrubs adapted to the area are
big sagebrush, rubber rabbitbrush, and green rabbitbrush.
At the Decker Mine in Montana, several species of wheatgrass
dominated the first-season production from a mixture of species.
Slender wheatgrass was especially vigorous. Smooth brome and sideoats
grama were also notable components of the stand.
May et al. (1971) found that both western wheatgrass and inland
saltgrass were well adapted to vegetative establishment on overburden
piles near Kemmerer, Wyoming. On saline-alkali soil materials, species
such as tall wheatgrass, alkali sacaton, Russian wildrye, and inland
saltgrass may be the best choice.
Shrub and tree species used in the revegetation of spoils are
primarily those that are native to the region, plus other adapted
species suited to specific soil conditions. In the Montana, Wyoming,
and North Dakota areas, shrubs such as silver buffaloberry, smooth
sumac, snowberry, winterfat, the sagebrushes, and the rabbitbrushes may
be used.
There are numerous native and exotic plant species that can be used
in strip mine reclamation. Nearly everyone involved in research on
revegetation of disturbed areas is constantly testing and evaluating
plants for particular environments. Species adaptability evaluations
are one of the main objectives of the research in Utah coal fields, as
mentioned later in this report.
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Availability of Plant Material
The availability of plant material, including seed and nursery
stock, can occasionally be an obstacle in revegetation programs.
Fortunately, seeds of a sufficient number of grass species are obtainable
in large quantities from commercial seed dealers. These are grasses
commonly used in the western United States for range and pasture reseeding.
Many native grasses and ecotypes are not grown commercially. Where such
species are especially well adapted, efforts must be made to contract
with seed collectors to gather them; and such seed will be expensive.
Sometimes the use of only a small amount of seed may enable the establish-
ment of a desirable species which can subsequently spread by natural
reproduction. Also, a species might gain a foothold from the planting of
container-grown plants at wide intervals over the site.
Seed of some shrub species is routinely collected by commercial
seed dealers. Bitterbrush, fourwing saltbush, saskatoon serviceberry,
blueberry elder, cliffrose, big sagebrush, and rubber rabbitbrush are
examples of shrub species for which seed is usually obtainable. Others
such as ephedra, winterfat, mountainmahogany, skunkbush sumac, and
wildrose are usually available in limited quantities. The availability
of seed of many shrubs (and native forbs) often depends upon whether
climatic conditions in local areas have been conducive to a good seed
crop.
Seed of most shrub and forb species is often too expensive to use
in large scale direct seeding. This is one reason why many species are
grown in nursery beds and greenhouses for transplanting to the field
site. In so doing, rare or expensive seed is used more efficiently.
Most planting stock of species not used for landscaping is grown by
Federal and State nurseries. One commercial greenhouse operator in Salt
Lake City, Utah (Native Plants, Inc.) has attempted to specialize in
native shrubs for revegetation programs.
Equipment for Revegetation
Equipment useful in revegetating mine spoil areas is usually
readily available. Earthmoving machines and farm implements can be
used to prepare the seedbed. Only where spoil and soil materials are
extremely rocky or where the terrain is steep is specialized equipment
needed. The U.S. Forest Service Equipment Development Center at Missoula,
Montana, is testing two new machines, the rotovator and the gouger, for
their usefulness in preparing disturbed areas for seeding and planting.
Both machines were used in the studies described later.
The rotovator functions as a heavy-duty rototiller. It may be
used to loosen up the soil material and to incorporate various types of
soil amendments in the top foot (30 cm) of the soil. The gouger forms
regularly spaced, small basins (depth can be regulated) that serve to
collect precipitation and decrease surface runoff and erosion.
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One of the most useful pieces of equipment for direct seeding on
rough sites is the rangeland drill, a rugged seeder with high clearance
for working over large rocks. It can be converted to a deep-furrow
implement by removing the depth bands. The depth of the furrow can be
controlled by taking off or adding disk arm weights. Packer and Aldon
(1978) briefly discuss several other types of direct seeding equipment
and their uses.
Certain equipment would be required for installing any needed
irrigation system. If irrigation water is available, much greater
confidence in successful plant establishment is justified despite drought
conditions. Supplementary water can be applied by overhead sprinklers,
trickle irrigation, or subsurface irrigation.
Improving the efficiency of natural precipitation by shaping the
seedbed in specific ways is another method of increasing soil moisture.
Contour furrowing, pitting, gouging, or the creation of imprinted
patterns (Dixon and Simanton 1977) can conserve precipitation and
direct it to where it is needed most. The erection of snow fences can
result in several times as much snow buildup over local areas than N
would normally occur. Water harvesting techniques may be effective.
Aldon and Springfield (1975a, 1975b) reported increased survival and
growth of fourwing saltbush and western wheatgrass transplants where
ground paraffin or polyethylene were applied over small basins around
the plants. Such techniques partially or entirely seal the soil surface
against evaporation and concentrate water immediately surrounding the
plant.
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FOREST SERVICE STUDIES AT THE ALTON COAL FIELD, UTAH
New Forest Service Studies in Utah, which began in the autumn of
1976, were designed to provide further guidelines and criteria for the
revegetation of coal spoils on semi-arid lands, including the use of
nonmine wastes as soil amendments. Four separate studies are summarized
in this report.
Revegetation Techniques on Disturbed Overburden from Simulated Mining
The objectives of this study were: (1) to evaluate three different
soil surface cultural treatments following severe site disturbance
termed "simulated mining," and (2) to compare effects of simulated
mining and no simulated mining on plant establishment and growth.
An 8-acre (3.2 ha) site (464 x 800 feet or 139 x 240 m) covered by
an old-growth juniper-pinyon stand was cleared and fenced to exclude
deer and rabbits. Simulated mining involved stockpiling topsoil,
ripping the subsoil to a depth of 30 inches (76 cm), smoothing the
furrows with a dozer blade, and replacing the topsoil. Topsoil was
stockpiled into two windrows by pushing it inward from the top and
bottom edges and outward from the middle with a dozer blade (Figure 6).
Figure 6. Topsoil stockpiled in windrows was respread following ripping
of the subsoil.
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The surface cultural treatments following simulated mining were:
(1) contour furrowing with three ripper teeth on the back of a D-6
caterpillar tractor; (2) pitting or gouging with a machine specially
designed to leave a waffle-like surface (gouger); and (3) rotovating
grass hay at 2-1/2 tons per acre (0.9 metric tons/ha) to a depth of 8
inches (20.3 cm) into the soil surface. The fourth treatment involved
leaving topsoil in place but gouging it to loosen the surface. This
treatment occupied the two 32-foot- (9.6 m) wide strips on which topsoil
had been stockpiled, plus two small areas of about 1/2 acre (0.2 ha)
each, one on each end of the long axis of the study site.
A seed mixture of the species shown in Table 6 was broadcast over
all four treatments using hand-operated cyclone seeders:
TABLE 6. SEED MIXTURE USED ON LARGER STUDY AREAS AT ALTON COAL FIELD
Intermediate wheatgrass
Pubescent wheatgrass
Fairway wheatgrass
Russian wildrye
Nomad alfalfa
Yellowblossom sweetclover
Bitterbrush
Fourwing saltbush
Winterfat
Green ephedra
Cliffrose
Total
Lbs/ac
4
4
4
4
1
1
2
2
0.5
1
1
247T
4.50
4.50
4.50
4.50
1.10
1.10
2.25
2.25
0.55
1.10
1.10
27.45
The severe drought during the autumn of 1976 and first 4-1/2
months of 1977 precluded normal early spring germination and emergence
of seeds sown the previous autumn. However, fair to good germination
and emergence occurred on all treatments following a rainy period in
the latter half of May 1977.
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The most striking difference among these treatments was higher
frequency and numbers of grass seedlings on the area where hay was roto-
vated into the soil surface. At the end of the 1977 growing season,
presence of grass seedlings on square-foot (0.09 m2 ) plots showed 92
percent frequency on the area treated with grass hay compared to 52
percent frequency on the areas not treated with hay. Frequency of forbs
was 40 percent and 21 percent on hay and non-hay areas, respectively.
Comparable shrub frequencies were 4 percent and 2-1/2 percent. The most
prominent shrubs were fourwing saltbush, winterfat, and bitterbrush, in
that order. Mean maximum numbers of grass seedlings per square foot
(0.09 m2) was 12.8 for hay treated plots compared to 5.2 on plots not
treated with hay.
All surface cultural treatments were effective in limiting runoff from
high-intensity summer storms in 1977. Some sediment was deposited in the
bottoms of terraces and pits, but the result was not serious. Minor repairs
were made where a few small channels developed, mainly in wheel tracks left
by equipment. No such storms occurred on this site in 1978.
Above average precipitation during the winter of 1977-1978 produced
excellent growth of vegetation in the spring of 1978 (Figure 7). Smooth
brome was a prominent component of grasses where hay was used, indicating
that seed of this species was present in the hay used as organic soil amend-
ment. Monitoring of vegetative production and ground cover will extend over
the next 3 or 4 years to fully evaluate treatments.
I
Figure 7. A good cover of grasses, forbs, and shrubs, in the second growing
season (1978), occupies area where grass hay was rotovated into
soil.
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Effects of Organic Amendments on Growth of Selected Grasses
This study, established on a part of the 8-acre (3.24 ha) Alton site,
involved testing effects of all combinations of two soil types and three
organic amendments on growth of 10 selected grasses. Soil types included:
(1) topsoil replaced over subsoil after simulated mining, and (2) subsoil
only. Soil amendments included: (1) grass hay spread at 2-1/2 tons per acre
(0.9 metric tons/ha) and rotovated into the soil; (2) bark-woodfiber compost
spread 1 inch (2.5 cm) deep and rotovated into the soil; and (3) no amendment.
Seeds of 10 selected grasses were planted in small subplots on each of the
six larger main plots in a randomized block design having three replications.
Seed germination and emergence of grass seedlings did not occur until
late May 1977. Cursory observations in mid-June while seedlings were still
small and not fully established showed more seedlings present where organic
amendments had been used. At the end of the first growing season, grass
seedlings were most numerous on the grass hay amendment plots and fewest on
the bark-woodfiber compost plots (Table 7).
TABLE 7. MEAN MAXIMUM NUMBER OF PLANTS/SQUARE FOOT (0.09 m2) FOR
SOIL-AMENDMENT TREATMENTS*
Topsoil
hay
Subsoil
hay
Topsoil
check
Subsoil
check
Topsoil
compost
Subsoil
compost
5.48 5.34 4.54 4.18 4.16 3.58
*
Means underscored by the same line are not significantly different at
the 0.05 probability level.
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Survival of streambank (Agri) and fairway (Agcr) wheatgrasses was
superior among the ten species, whereas western wheatgrass (Agsm) and
Great Basin wildrye (Elci) showed fewest plant numbers (Table 8).
TABLE 8. MEAN MAXIMUM NUMBER OF PLANTS/SQUARE FOOT (0.09 m2)
FOR 10 SELECTED GRASSES*
Agri Agcr Elju Agin2 Brin Agel Agin Agtr2 Agsm Elci
5.99 5.79 4.97 4.84 4.54 4.46 4.42 4.14 3.22 3.08
Means underscored by the same line are not significantly different at
the 0.05 probability level.
Differences among the other six grasses were less important. Species
in descending order of maximum plant numbers were Russian wildrye (Elju),
intermediate wheatgrass (Agin2), smooth brome (Brin), tall wheatgrass
(Agel), beardless bluebunch wheatgrass (Agin), and pubescent wheatgrass
(Agtr2).
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Adaptability of Selected Grasses and Shrubs on Different Profile Materials
This particular study (begun in October 1976) was designed to determine
the effectiveness of different grass and shrub species in forming suitable
cover on different subsoil materials as well as on topsoil.
The study was established on four different types of overburden
above the coal seam on a 3-acre (1.2 ha) site having a 20 to 25 percent
slope and a westerly exposure. Juniper and pinyon trees were bulldozed
from the areas above and below the cut area exposing the coal seam.
The high sidewall was reduced by developing two terraces each about
25 feet (7.6 m) wide and 220 feet (67 m) long in the cut area. A 4- to
5-foot-(1.2 to 1.5 m) deep layer of dark, carbonaceous shale that lay
just above the coal seam was exposed on the surface on both terraces.
Three additional strips, each 50 x 220 feet (15 x 66 m), two above and
one below the terraces, were prepared with different types of overburden
on the surface. Starting at the top of the hill, the sequence of the
four treatments was as follows:
(1) A 50- x 220-foot (15.2 x 67 m) strip of topsoil was left in
place but ripped with dozer teeth to prevent runoff.
(2) A 50- x 220-foot (15.2 x 67 m) plot was stripped of approximately
1 foot (30 cm) of topsoil and 2 feet (61 cm) of gravelly clay
subsoil leaving a light-colored, clay-shale surface exposed.
This plot was also ripped to a depth of about 2 feet (61 cm) and
furrows were left to prevent runoff and erosion.
(3) Two 25-foot- (7.6 m) wide terraces were formed where dark
carbonaceous shale was exposed on the surface.
(4) A 50-foot- (15.2 m) wide strip of "fill" material consisted of
the gravelly clay subsoil from (2) above.
On each of these four soil types, 11 grasses were seeded in separate
plots, 10 feet wide and 50 feet long (3 m x 15 m), in two replications.
The drought during the autumn and winter of 1976-1977 prevented early
spring seed germination, but seedling emergence occurred in late May 1977.
By the end of the first growing season, survival of the seeded grasses
could only be considered as fair to good. Ranking of the above four treat-
ments in descending order of plant establishment and growth was: 1, 4, 3, 2.
All grass species exhibited fair to good growth, but some were superior to
others.
37
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Excellent winter precipitation and the relatively cool spring of 1978
was conducive to abundant growth of grasses. Smooth brome and several of
the wheatgrasses grew particularly well.
In early May 1978, container-grown plants of the following 10 shrub
species were planted on one replication of the study: fourwing saltbush,
Bonneville saltbush, winterfat, curlleaf mountainmahogany, true mountain-
mahogany, green ephedra, prostrate summer cypress (two varieties), skunk-
bush sumac, and bitterbrush.
A single row of each shrub species was planted across all 11 grass
plots on each of the four types of soil. Shrubs were planted approximately
5 feet (1.5 m) apart so that in any single row, two plants occurred in
each 10-foot-wide (3 m) grass plot. Rows were also spaced approximately
5 feet (1.5 m) apart so that all 10 shrub species occurred on each of
the four types of soil.
All shrubs survived well during the 1978 growing season. Growth
of shrubs and grasses will continue to be monitored for at least 3 to 4
more years to evaluate compatibility of shrub species with grass species
on different types of overburden.
Establishment and Longevity of Several Plant Species on Various
Topsoils and Shaley Overburden
Utah International Incorporated is a major holder of coal leases
in the Alton Coal Field of southern Utah. The company considers that
in a strip mining operation, carbonaceous shale directly overlying coal
seams would be most readily available as revegetation media.
Study objectives were: (1) to test the possibility of establishing
vegetation on the carbonaceous shale without topsoil and on carbonaceous
shale covered with three different kinds of topsoil, (2) to monitor
soil moisture and salinity regimes in topsoils and shale, and (3) to
determine the physical and chemical properties of the three topsoils
and carbonaceous shale.
38
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An 0.5-acre (0.2 ha) area approximately 7 miles (11.2 km) southeast
of Alton, Utah, was fenced to exclude deer, livestock, and rodents. Within
the exclosure, four soil materials were placed in plots 10 x 30 feet (3m x
9m) in size that had been excavated to a depth of 40 inches (100 cm), rep-
licated four times. Soil materials included: (1) shale overburden taken
from directly above a coal seam, (2) sandy loam topsoil, (3) loam topsoil,
and (4) silty clay topsoil. Each topsoil common to a part of the coal field
was spread to a,depth of 10 inches (25 cm) over a 30-inch (76 cm) layer of
the shale overburden that had been placed first in the excavated pits.
Sensors for monitoring soil moisture and salinity were placed at depths of
8, 18, and 30 inches (20, 46, 76 cm) in each plot. One-half of each plot
was fertilized with 80 Ib/acre (90 kg/ha) of both elemental nitrogen and
phosphorous, and all plots were broadcast-seeded with a mixture of six
grasses, six forbs, and six shrubs, in November 1976. Differences in plant
density and ground cover will be determined and analyzed over the next 3
years.
Seed germination was delayed by lack of soil moisture until late
May 1977. Although seedling establishment appeared adequate on the sandy
loam topsoil and on the shale overburden for satisfactory vegetative cover,
all plots were reseeded in November 1977 in an effort to obtain better
vegetative stands.
Through the early part of the second growing season (June 1978),
"drylander" alfalfa from Saskatchewan provided most of the vegetative
cover on all plots. However, fairway wheatgrass showed good establishment
and vigor and should ultimately form a substantial portion of the stand
on most plots. Excellent individual plants of Russian wildrye, Indian
ricegrass, small burnet, globemallow, winterfat, and fourwing saltbush
also occurred. Shrub species such as true mountainmahogany, green ephedra,
and antelope bitterbrush have yet to exhibit good growth on any of the
soils.
Chemical and physical analyses showed that other than being low in
available nitrogen, none of the three topsoils or shale overburden were
unsuited for plant growth. Although no apparent benefits resulted from
the addition of inorganic fertilizer to the four soil materials, soil
moisture probably was inadequate during the first growing season; by the
second growing season, nitrogen might have dissipated. Further testing
is necessary.
To date, best overall vegetative cover has been obtained on plots
having 10 inches (25 cm) of sandy loam topsoil over the shale overburden,
followed by the loam topsoil over shale overburden. The shale overburden
itself currently ranks third among the four growing media in vegetative
cover. After weathering over winter, the shale overburden has excellent
moisture-holding capacity and has been an excellent seed germination medium.
In contrast, the silty clay topsoil has proven to be the poorest material
with respect to seedling germination and establishment.
39
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CONCLUSIONS AND RECOMMENDATIONS
Grass hay spread at 2-1/2 tons per acre (0.9 metric tons/ha) and roto-
vated 8 inches (20 cm) deep into the topsoil increased seedling survival of
grasses, forbs, and shrubs during the first growing season on a simulated
mining tract at the Alton coal field. Where available at reasonable cost,
use of hay is recommended to increase moisture-holding capacity and improve
seedling establishment. Surface configurations such as gouging (pitting)
and contour furrowing should also be used to retain precipitation in the
form of snow or rain on reconstructed areas.
Plants of streambank and fairway wheatgrasses were most abundant
the first year among 10 grass species broadcast-seeded at equal rates in
separate plots at Alton. Other species in order of descending numbers of
plants were: Russian wildrye, intermediate wheatgrass, smooth brome, tall
wheatgrass, beardless bluebunch wheatgrass, pubescent wheatgrass, western
wheatgrass, and Great Basin wildrye. The latter two species, plus stream-
bank and beardless bluebunch wheatgrasses, are native; the other grasses
are introduced. Two or three of the native grasses and a similar number
of introduced species should be used in a mixture with selected forbs and
shrubs for revegetating disturbed areas. Recommended forbs include alfalfa,
sweet clover, small burnet, Utah sweetvetch, and scarlet globemallow.
Recommended shrubs include fourwing saltbush, winterfat, and bitterbrush
among other species now being tested.
When weathered over winter, the dark carbonaceous shale (clay loam)
lying immediately above the coal seam has good water-holding capacity, but
it is best suited as a growing medium for plants if covered with approxi-
mately 1 foot (30 cm) of sandy loam or loam topsoils. These two kinds of
topsoils were superior to other profile materials as growing media for
plants. The dark carbonaceous shale was superior to a blue-colored shale
overlying the carbonaceous shale and also to a siJLty clay topsoil found on
part of the area.
40
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Packer, P. E., and E. F. Aldon. 1978. Revegetation Techniques for Dry
Regions, pp. 33-40. In: Proc. High Altitude Revegetation Workshop 2.
R. H. Zuck, and L. F. Brown (eds.). Colorado St. Univ., Fort Collins,
Colorado.
Sanks, R. L., and A. Amirtharajah. 1976. Evaluation of Solid Waste as
Physical and Chemical Amendments and Revegetation of Coal Surface Mine
Spoils. Unpublished Final Report. Dept. Civil Eng. and Eng. Mech.,
Montana St. Univ., Bozeman, Montana. 16 pp.
Schaal, L. 1973. 1968-69 Semi-Works Plot Field Experiment, pp. 49-56.
In: Processed Shale Revegetation Studies. Bloch, M. B., and P. D.
Kilburn (eds.), Colony Development Operation, Denver, Colorado.
Schaal, L. 1973. Greenhouse Experiments of Plant Growth in Processed
Shale, pp. 27-38. In: Processed Shale Revegetation Studies. Bloch,
M. B. , and P. D. Kilburn (eds.), Colony Development Operation, Denver,
Colorado.
Schmehl, W. R., and B. D. McCaslin. 1973. Some Properties of Spent Oil
Shale Significant to Plant Growth, pp. 7-25. In: Processed Shale
Revegetation Studies. Bloch, M. B., and P. D. Kilburn (eds.), Colony
Development Operation, Denver, Colorado.
Springfield, H. W. 1972. Using Mulches to Establish Woody Chenopods. In:
Int. Symp. on Wildland Shrubs, Their Biology and Utilization, pp. 382-
391. USDA For. Serv. Gen. Tech. Rep. INT-1. Int. For. and Range Exp.
Sta., Ogden, Utah. 494 pp.
Williams, B. W., and P. E. Packer. 1977. Sewage Sludge and Other Organic
Materials as Amendments for Revegetation of Spent Oil Shale. Proc.,
Symp. on Municipal Waste Water and Sludge Recycling on Forest Land and
Disturbed Land, Univ. of Pennsylvania, Philadelphia, Pennsylvania.
March 1977. pp. 291-294.
Williams, S. E. and E. F. Aldon. 1978. Endomycorrhizal (Vesicular
Arbuscular) Associations of Some Arid Zone Shrubs. Southwest Nat.
20:437-444.
Willmuth, W. H. and E. J. DePuit. 1977. Effects of Fertilizer Rate, Times
of Application, and Season of Seeding on a Mine Spoil Rehabilitation
Planting. 1976 Annual Progress Report. Reclamation Res. Unit, Montana
Agri. Exp. Sta., Montana St. Univ. Bozeman, Montana.
43
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APPENDIX
LIST OF PLANT SPECIE'S CITED IN THIS REPORT
GRASSES:
Scientific Name
Agropyron cristatum
A. dasystachyum
A. elongatum
A. inerme
A. intermedium
A. riparium
A. smithii
A. trachycaulum
A. trichophorum
Bouteloua curtipendula
B. gracilis
Bromus inermis
Buchloe dactyloides
Distichlis spicata var. stricta
Elymus cinereus
E. junceus
Festuca ovina var. duriuscula
Hilaria jamesii
Oryzopsis hymenoides
Sporobolus airoides
S. cryptandrus
Common Name
Fairway wheatgrass
Thickspike wheatgrass
Tall wheatgrass
Beardless bluebunch wheatgrass
Intermediate wheatgrass
Streambank wheatgrass
Western wheatgrass
Slender wheatgrass
Pubescent wheatgrass
Sideoats grama
Blue grama
Smooth brome
Buffalograss
Inland saltgrass
Great Basin wildrye
Russian wildrye
Hard fescue
Galleta
Indian ricegrass
Alkali sacaton
Sand dropseed
44
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FORBS:
Astragalus cicer
Balsamorhiza sagittata
Hedysarum boreale
Medicago media
M. sativa
Melilotus officinalis
Penstemon spp.
Sanguisorba minor
Sphaeralcea coccinea
Swainsona salsula
Cicer milkvetch
Arrowleaf balsamroot
Utah sweetvetch
"Drylander" alfalfa
Alfalfa
Yellow sweetclover
Penstemon
Small burnet
Scarlet globemallow
Swainsonpea
TREES AND SHRUBS:
Amelanchier alnifolia
Artemisia nova
A. pygmaea
A. tridentata tridentata
A. tridentata vaseyana
Atriplex aptera
A. bonnevillensis
A. canescens
A. cuneata
A. gardneri
A. lentiformis
A. obovata
A. polycarpa
A. saltilloensis
Camphorosma monspeliaca
Caragana arborescens
Ceanothus cuneatus
Ceratoides lanata
C. papposa
Cercocarpus ledifolius
C. montanus
Chrysothamnus nauseosus albicaulis
45
Saskatoon serviceberry
Black sagebrush
Pygmy sagebrush
Big sagebrush
Mountain big sagebrush
Shortwinged saltbush
Bonneville saltbush
Fourwing saltbush
Castle Valley clover
Gardner saltbush
Big saltbush
Broadscale saltbush
Cattle saltbush
Blue saltbush
Mediterranean camphorfume
Siberian peashrub
Wedgeleaf ceanothus
Winterfat
Plumed white sage
Curlleaf mountainmahogany
True mountainmahogany
White rubber rabbitbrush
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C. viscidiflorus
C. viscidiflorus stenophyllus
Cowania mexicana
Elaeagnus angustifolia
Ephedra viridis
Forestiera neomexicana
Juniperus scopulorum
Kochia prostrata
Lonicera tatarica
Picea engelmannii
Populus spp.
Potentilla fruticosa
Purshia tridentata
Rhus glabra
R. trilobata
Robinia neomexicana
Rosa woodsii
Salix alba var. vitellina
Sambucus cerulea
S. racemosa pubens microbotrys
Shepherdia argentea
Symphoricarpos oreophilus
Ulmus parvifolia
Green rabbitbrush
Narrowleaf low rabbitbrush
Cliffrose
Russian-olive
Green ephedra
New Mexico forestiera
Rocky Mountain juniper
Prostrate summer cypress
Tatarian honeysuckle
Engelmann spruce
Cottonwood
Bush cinquefoil
Bitterbrush
Smooth sumac
Skunkbush sumac
New Mexico locust
Woods rose
Golden willow
Blueberry elder
Red elder
Silver buffaloberry
Mountain snowberry
Chinese elm
46
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/7-79-068
3. RECIPIENT'S ACCESSI ON- MO.
4. TITLE AND SUBTITLE
Revegetating Processed Oil Shale and Coal Spoils on
Semi-Arid Lands - Interim Report
5. REPORT DATE
February 1979 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
Neil Frischknecht and Robert B. Ferguson
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
Intermountain Forest and Range Experiment Station
Forest Service
U. S. Department of Agriculture
Provo, Utah 8U601
EHE 623
11. CONTRACT/GRANT NO.
IAG DE-E76U
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
II. S. Environmental Protection Agency
Cincinnati, Ohio 1*5268
13. TYPE OF REPORT AND PERIOD COVERED
Interim 6/75 - 6/78
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Forest Service revegetation studies on TOSCO II processed shale (beginning in
1976) at Sand Wash, eastern Utah, within the salt desert shrub zone and at Davis
Gulch, western Colorado, in the upper mountain brush-zone, involved the use of amend-
ments on processed shale without leaching salts. At Sand Wash, seven species of the
Chenopodiaceae family were far superior to other species on processed shale with or
without supplementary water or a covering of soil. Where at least 1 foot (30 cm) of
soil covered processed shale, an additional eight species showed good survival. At
Davis Gulch, a covering of 8 to 12 inches (20 to 30 cm) of topsoil over processed
shale greatly increased survival and growth of container-grown plants compared to a
2- to 3-inch (5 to 7.5 cm) covering of broken rock fragments or a cover of barley
straw crimped into the processed shale.
On a simulated mining tract at the Alton coal field, southern Utah, grass hay
rotovated 8 inches (20 cm) deep into the soil increased seedling survival. Where
several overburden materials were tested as growing media for plants, sandy loams
and loam topsoils gave best results while a dark-colored carbonaceous shale
material (clay loam) lying immediately above the coal seam gave better results
than the poorest topsoil (silty clay).
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
"25
2B
2D
8G
81
13B
Oil Shale
Coal Mining
Semiarid land
Spoil
Grasses
Tosco
Spent Shale
Revegetating
Utah
Colorado
Irrigation
18. DISTRIBUTION STATEMENT
Release to the Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
55
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
47
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