The Effects of Roundup®
on Eisenia fetida
Nathan Brownrigg
Senior Capstone
Spring 2005
Topics to be Discussed
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Background Information
Materials and Methods
Results
Discussion of Results
Questions
Background Information
 Roundup® is a
common herbicide.
 Glyphosate is the
active chemical. It is
also used in many
other herbicides.
 Ingredients:
Glyphosate 18%,
Diquat Dibromide
0.73%, Others
81.27%.
Background Information
 Generally used to kill weeds and grasses.
Tree stumps can also be killed by drilling holes
into a fresh stump and applying the
concentrated herbicide into the holes.
 The herbicide is applied to the foliage of the
plant and it systemically moves to the roots.
 The chemical works by preventing the plant
from producing certain amino acids.
 This inhibits protein synthesis in the plant and
eventually kills it.
Background Information
 Glyphosate is generally not active in the
soil (it is applied to foliage).
 Strongly absorbed by the soil.
 Half-life can range from 3-130 days.
 Eventually broken down by soil
microorganisms.
 Effects on soil invertebrates not known.
Background Information
 Eisenia fetida
 Known as redworms.
 Very important
compost organism.
 Commonly bred for
use in compost
heaps.
Background information
 Earthworms in general are important soil
invertebrates. Their burrowing and
feeding activities enhance soil fertility by
incorporating thatch throughout the soil.
 Because so much soil passes through
their bodies and they are in constant
contact with the soil, there is a significant
possibility of toxins becoming
concentrated within them.
Background Information
 Because of possible toxin build up,
earthworms can be used as bioindicators
of pollution in the soil.
Topics to be Discussed
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Background Information
Materials and Methods
Results
Discussion of Results
Questions
Materials and Methods
 Roundup®
superconcentrate
was obtained from
local lawn and
garden center.
 Enough to treat
3,000 sq ft. (using
recommended
amount).
Materials and Methods
 Containers were
prepared by adding
approximately 1,000
grams of soil.
 Soil depth was about
3 cm, which was
recommended by the
Carolina Biological
Supply Co.
Materials and Methods
 In all, 12 containers
were prepared this
way.
 One other container
was filled with a little
more soil to maintain
the earthworms not
to be used in the
experiment.
Materials and Methods
 Earthworms were then
counted into groups of
50 and weighed using an
electronic balance and
placed in one of the 12
containers.
 These numbers later
serve as the initial
biomass of the
earthworms.
Materials and Methods
 The recommended concentration for
Roundup®:
 6.0 fl oz. per gallon of water.
 Converted for experimental use; the
recommended concentration:
 14.1 ml Roundup® per 300 ml solution
(distilled H2O + herbicide.) (4.7%)
Materials and Methods
 Concentrations were then determined for
experimental use:
 Control: 0.00 (distilled H2O)
 Experimental groups: 7.05(2.4%),
14.1(4.7%), 28.2(9.4%), 42.3(14.1%), and
70.5(23.5%) ml Roundup® per 300 ml
solution.
Materials and Methods
 The concentrations were applied to each
container.
 One concentration per container, 6
concentrations, 12 containers = two
experiments running concurrently.
Materials and Methods
 The containers were
then left to incubate
for 30 days.
 Day 14: Moist corn
meal was applied to
the soil for food (as
instructed by Carolina
Biological Supply Co.
manual).
Materials and Methods
 Worms removed and reweighed after 30
days.
 Weight was compared to original biomass.
 Number of dead worms was also
recorded.
Topics to be Discussed
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Background Information
Materials and Methods
Results
Discussion of Results
Questions
Results
 Too many earthworms from trial 1 died to
collect data.
 Due to dehydration (no mortality was
observed in other three trials).
 The following tables and graphs show the
results from trials 2-4.
Results
Biomass of Earthworms Before and After Exposure to
Roundup® (Trial 2)
Concentration
(%)
Original Biomass
(g)
Biomass Following
Exposure (g)
Difference
(g)
0.0
14.3
14.4
(+) 0.1
2.4
15.2
15.2
0
4.7
13.9
13.7
(-) 0.2
9.4
15.6
15.5
(-) 0.1
14.1
14.9
13.6
(-) 1.3
23.5
14.6
14.3
(-) 0.3
Biomass After Exposure (Trial 2)
Biomass
After Exposure (Trial 2)
1
Percent Increase/Decrease
0
Percent Increase/Decrease
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
0.01
0.01
0
0
-0.7
-1.5
Control
1 -0.7
-2.1
-1.5
-2.1
Control
2.40%
2.40%
4.70%
4.70%
9.40%
9.40%
14.10%
14.10%
23.50%
23.50%
-8.7-8.7
Concentration
Concentration
Results
Biomass of Earthworms Before and After Exposure to
Roundup® (Trial 3)
Concentration
(%)
Original Biomass
(g)
Biomass Following
Exposure (g)
Difference
(g)
0.0
14.8
15.3
(+) 0.5
2.4
15.7
15.5
(-) 0.2
4.7
14.9
14.5
(-) 0.4
9.4
14.9
14.3
(-) 0.6
14.1
14.5
14.1
(-) 0.4
23.5
13.6
13.1
(-) 0.5
Biomass After Exposure (Trial 3)
Biomass
After Exposure (Trial 3)
0.5
Percent Increase/Decrease
0
Percent Increase/Decrease
-0.5
1
0.03
0.03
0
Control
-1
-1.5
-2
-2.5
-1
-2
-3
-3
-3.5
-4
-4.5
Control
2.40%
1
2.40%
-1.3
4.70%
4.70%
-1.3
9.40%
9.40%
14.10%
-2.7
-2.7
-4
-5
14.10%
23.50%
-2.8-2.8
-4.1
-4.1
Concentration
Concentration
23.50%
-3.7
-3.7
Results
Biomass of Earthworms Before and After Exposure to
Roundup® (Trial 4)
Concentration
(%)
Original Biomass
(g)
Biomass Following
Exposure (g)
Difference
(g)
0.0
15.9
16.2
(+) 0.3
2.4
15.9
15.8
(-) 0.1
4.7
14.1
13.7
(-) 0.4
9.4
15.2
14.8
(-) 0.6
14.1
16.8
16.3
(-) 0.5
23.5
13.5
13.1
(-) 0.4
Biomass After Exposure (Trial 4)
Biomass
After Exposure (Trial 4)
1
1
Percent Increase/Decrease
Percent Increase/Decrease
0
-1
-1
-2
-3
-3
Control
-0.7
1
-0.7
Control
2.40%
2.40%
4.70%
4.70%
-5
-6
9.40%
9.40%
-2.7
-2.7
-4
-5
-6
0.02
0
-2
-4
0.02
-3
-3
-3
-3
14.10%
14.10%
23.50%
23.50%
-4.9
-4.9
Concentration
Concentration
Average Biomass After Exposure (Trials 3,4)
0.5
0.025
0
1
Percent Increase/Decrease
-0.5
Control
-1
-1
2.40%
-1.5
4.70%
-2
9.40%
14.10%
-2.5
23.50%
-3
-2.9
-3.5
-4
-3.4
-3.8
Concentration
-3.35
Topics to be Discussed





Background Information
Materials and Methods
Results
Discussion of Results
Questions
Discussion of Results
 These numbers indicate that Roundup®
has a negative effect on the biomass of
Eisenia fetida. However, the herbicide is
not fatal to the earthworms at these
concentrations.
Discussion of Results
 Concentrations above the recommended
did not consistently decrease the
biomass of the earthworms.
 Experimental error may have had an
effect on trial 2. However, this was
corrected and results of trials 3 and 4
were relatively consistent.
Questions????????
References
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Bauer C., Rombke J. 1996. Factors influencing the toxicity of two
pesticides on three lumbricid species in laboratory tests. Soil Biol.
Biochem. 29, 705-708.
Callahan C.A. 1984. Earthworms as ecotoxicological assessment tools.
United States Environmental Protection Agency, EPA-600/D-48-272.
Mosleh Y.Y., Paris-Palacios S., Couderchet M., Vernet G. 2003. Acute
and sublethal effects of two insecticides on earthworm (Lumbricus
terrestris L.) under laboratory conditions. Environ. Toxicol. 18(1), 1-8.
Mosleh Y.Y., Paris-Palacios S., Couderchet M., Vernet G. 2002. Effects
of the herbicide isoproturon on survival, growth rate, and protein content
of mature earthworms (Lumbricus terrestris L.) and its fate in the soil.
Applied Soil Ecology 23, 69-77.
Pendergrass W. 1980. Carolina Protozoa and Invertebrates Manual.
Carolina Biological Supply Company. Burlington, NC. 34
Acknowledgements
 Dr. McShaffrey
 Dr. Pate