University of Georgia Reclamation
Update
by Kathleen McEvoy
What soil preparation
measures improve survival and growth of loblolly pine seedlings
on kaolin mined areas? Are certain grasses that are beneficial
for wildlife also better at controlling erosion? Will application
of a composted paper mill by-product, that adds organic matter
and nutrients, have a positive effect on reclamation success?
The University of Georgia (UGA), with help from the Georgia
China Clay Producers Association, is actively pursuing answers
to these questions. Such answers will lead to better reclamation
practices on kaolin mined areas.
Successful kaolin
mine reclamation requires good soil conditions for plant growth,
vegetation establishment for erosion control, and an environment
that enhances biological processes. During reclamation, soil
can be compacted, which decreases the soil pore space. This
limits water holding capacity and soil rooting volume resulting
in reduced root growth and seedling success. Soil tillage helps
correct these adverse conditions and is particularly important
during the critical first years of reclamation. Two tillage
practices are being studied, subsoiling and disking. Subsoiling,
as its name implies, breaks up the subsoil layer to a depth
of about 18 inches. This can have a greater impact on development
of seedling roots than any other soil tillage treatment. Subsoiling
increases the soil volume available to roots and improves their
ability to reach water and nutrients. With the expected drought
summer 1998, it will be important to observe if the seedlings
planted on subsoiled areas have greater growth. Disking, the
other tillage practice being studied, improves rooting conditions
in the soil surface. This increases the volume of large pores
in the surface soil which allows for more water and air transport.
Research being conducted will compare the two tillage treatments
and their effectiveness in ameliorating soil conditions in kaolin
mined areas.
Vegetative cover,
particularly grass species, can reduce soil erosion and prevent
sediment loss into rivers and streams. Immediate establishment
of grass is critical after the land is disturbed. A vegetative
cover not only protects the soil, it can provide habitat and
forage for wildlife. Current research conducted by UGA focuses
on the establishment of grasses that are beneficial for wildlife
yet effective for controlling erosion. The study site is located
on an area that was previously mined for kaolin. Three seed
mixtures are being compared, two fall wildlife seed mixtures
and one mixture commonly use by the kaolin mining companies.
The wildlife mixtures are rated by individuals from the Natural
Resources Conservation Service and industry as being very good
for deer, rabbits, and turkeys in areas with moderate potential
for erosion. Loblolly pine trees were planted this winter after
the vegetative cover was established. We will measure pine tree
growth and also compare the competition between grass and tree
seedlings for nutrients and water. Results from this segment
of the study are still being collected and analyzed and will
be posted at a later date.
An opportunity
for immediate amendment of the kaolin mined spoil can result
from the use of a composted paper mill by-product mixed with
chicken litter. Too often, these kind of materials end up in
landfills. This material acts as a mulch, which helps retain
soil moisture and decreases soil temperatures. Both can have
a positive effect on root growth. This material is also a source
of nutrients, such as nitrogen. Previous studies indicate improved
soil physical properties and increased plant growth with the
use of a composted papermill by-product. We will measure the
effects of the composted material on loblolly pine growth.
Funding from
the China Clay Producers Association makes this research possible.
Continued dedication and innovative thinking is required to
advance mine reclamation as well as promote education. Specific
questions regarding this research project may be addressed to
mcevoy@arches.uga.edu.
About the Author
China
Clay Producers Association
Lee Lemke
Executive Vice President
113 Arkwright Landing
Macon, Georgia 31210
Telephone 478-757-1211
Fax 478-757-1949
Email:
info@georgiamining.org |
 |