2012-06-20_PERMIT FILE - C2010089 ‎(61)‎

• Permit No: C2010089
• IBM Index Class Name: PERMIT FILE
• Doc Date: 6/20/2012
• Doc Name: Energy MineTopsoil Segregation Study
• Section_Exhibit Name: Appendix 2.05.4‎(2)‎‎(d)‎-2
• Media Type: D
• Archive: No

and subsoil were segregated during the removal
and respreading process. They reccnme ded topsoil
and subsoil should not be mixed to avoid dilution
of the beneficial properties of the topsoil.
Four year results from this study were given
by Power et. al. (1981). Yields tended to
increase from no topsoil, mixed topsoil and
subsoil, and respread topsoil over subsoil.
They reported yields obtained from the perennial
species in the mixe it treatment were
within 90`I of 1 e_45-..QUAin it _ th
horizon treatments.$ and only when crop production
use, does the segregation of e topsoil and mining bsoil
appear warranted.
Topsoil handling practices similar to those
utilized during mining were evaluated by Biondini
et al. (1985). This study reported recovery
of dehydrogenase activity and mycorrhizae
infection potential after six years was not
different between slight and severe levels of
soil disturbance. Such findings were not
anticipated and are somewhat inconsistent with
the strategies for increasing plant community
diversity on reclaimed lands reported by DePt
(1984) and Allen (1984).
decreasing levels of soil disturbance should
produce increased levels of plant community
diversity. The findings of Biondini et. al.
(1985) suggest the rate of plant succession
is 'inversely correlated with the level of soil
disturbance.
Considerably more research has been conducted
plant oHargis topsoil
and thickness
Redente
(1984) and Doll et. al. (1984) reviewed the
extensive literature on topsoil thickness and
concluded the optimum depth of topsoil on a
given site is a function of spoil characteristics
h
precipitation and plant forms. Working
materials obtained from the Energy
northwest Colorado, McGinnies and Nicholas (1980)
reported a highly significant positive correlation
between yields in a greenhouse study as soil
thickness increased from 0 cm to 46 cm. Stand
ratings in the field during the second growing
season were reported to have a similar
correlation.
Barth (1984) constructed depth studies
at 15 sites which were evaluated for a six year
period in the Northern Great Plains. He reported
the optimum biomass response of cool season
perennial grasses was dependent on the spoil
traits of each particular site. The depth of
respread soil to achieve optimum production
ranged from 0 to 71 cm. f A significant increase
in _ praductian__._p. _sh l over _ 4j1_ -depth$._ -mil
observed during .thy, _last..ye;�rs af_.this..study.
Garth reported the optimum soil depth requirements
become more clearly defined with time. On sodic
spoil in !forth Dakota, Power et. al. (1981)
reported optimum crop production four years
after planting was associated with respread
soil depths of between 75 and 120 cm. Pinchak
et. al. (1985) reported on the four year results
from a topsoil depth study in Wyoming. Maximum
production of seeded species was associated
with the deepest soil depth (60 cm) while maximum
production of nonseeded species was associated
with the 0 and 20 cm topsoil treatments. Maximum
biomass by individual species was found to vary
across soil depth. Highest species diversity
and richness values were associated with the
40 em soil depth. On the Wyoming study, Schuman
et. al. (1985) reported maximum biomass of seeded
species shifted from the 60 cm depth to the
40 cm depth five years after seeding.
Redente and Hargis (1984) reported on
the third year results of a topsoil thickness
study conducted in northwest Colorado. Treatment
depths were 15, 30, 45 and 60 cm. Maximum biomass
of seeded grasses and volunteer species was
associated with the 60 cm depth while maximum
biomass of seeded forbs and shrubs was associated
with the 15 cm depth. Halverson et. al. (1987)
reported increased wheat and corn yields were
associated with the 60 cm topsoil depth for
the first two years following planting, but
during years three through six, maximum wheat
and corn yields were usually associated with
the 30 cm depth. They also reported little
benefit could be obtained by applying more than
15 cm of respread topsoil, and also reapplication
of more than 30 cm of coarser textured topsoil
over fine textured spoil appeared to reduce
the productivity of the reclaimed site.
In western Colorado, Redente and Ruiz°
(1979) compared second year retorted oil shale
biomass at respread soil depths of 30.5, 61
and 91.5 cm. Maximum biomass was reported
the 91.5 m depth. These for
a
highly significant correlation between forage
production and soil depth. They also suggested
the optimum soil depth to reclaim spent oil
shale may change over time. Fifth year results
of this study were reported by iiondini et.
al. (1984). For the introduced seed mixture,
the 30 cm plots were dominated by alfalfa
(Medics o sativa) while cool season perennial
grasses dominated the 60 cat plots. They reported
the rate of succession appeared to be inversely
correlated with the thickness of respread soil
and management inputs. The plant successional
aspects of this study four years after seeding
were reported by Biondini and Redente (1986).
Species diversity was found to be negatively
correlated with increasing biomass production,
thickness of respread soil, age of the seeded
stand and the presence of certain regulatory season
grasses. They concluded the reg
of high diversity and high production were
mutually exclusive and increased species diversity
might be achieved by reducing stimulus factors
(i.e. irrigation, fertilization and thick layers
of respread topsoil).
The purpose of this study is to evaluate
long terra plant response relative to segregation f to
of soil horizons and varying p t respread