Soil Quality Experiments
Problem: Excess amounts of nitrates in the soil from fertilizer runoff from farms to small gardens into our lakes.
Information: We learned from Dr. Evan Kane (Forestry, Michigan Technological University), that deep-rooted perennials continue to take nitrates from the soil outside of the normal growing season. Perennials are plants that don't die after one season, but rather survive the winter and continue to live, or become 'active' again the following spring. To test this idea, and hopefully determine the best grass to use for gardens, we designed an experiment using bluestem (a native perennial), alfalfa (a non-native perennial that is proven to remove excess nitrates), and a non-native annual grass seed. Hypothesis: If the performance of annual and perennial grasses are compared, the perennial grasses should remove more nitrates from the soil. Experiment #1 Procedure:
Results (Experiment #1): Data Table Conclusion:
Both grass types lowered the nitrate concentration in the soil, but the annual grass did a better job. A reason why the results could have ended up this way might be because we did not give the blue stem roots enough time to fully develop, so it could not absorb as much nitrates as it could have in the short time frame. Also, the annual grass grows faster than the blue stem, giving it an advantage. If we do this experiment again, then we would give the blue stem more time to grow so it can fully develop; from what we have learned, bluestem should perform better over greater lengths of time. Application: School community: We have already begun to apply what we have learned within our school community to reduce the impact of fertilizing our school garden. We planted bluestem (which showed better germination times and tolerance to wet environments during our experiment) around the school garden to act as a barrier against the flow of excess nitrates in groundwater. We looked up studies that tested this method of nitrate reduction along the borders of larger, more traditional farm fields; in the Minnesota-based studies, the borders were usually 1-2 meters wide, but since our area is so small, we scaled the border down to only a few inches wide. Larger Impact: We will be presenting our experiment results and conclusions to the Michigan Department of Transportation (MDOT), along with the results of additional experiments. (Update coming soon - we will compare bluestem germination rate, general performance, and health under stressful conditions to that of 4 common seed mixes used by MDOT in their rehabilitation and roadside projects). |
Our Second Experiment
Problem: How does the hardiness of each MDOT seed mix in different environments compare to big bluestem?
Information: Although the ability of the grass to absorb nitrates is very important for our proposal, we also need to know how well it will survive in environments that aren't ideal. This is especially important in our area because the roads get a lot of salt which effect how long a plant might live. There is also a very wet environment when the snow melts.
Hypothesis: If the survivability of annual seed mixes and perennials such as bluestem are tested in harsh environments, then the perennials will survive better then the annual seed mixes.
Experiment #2 Procedure:
#1: Gather materials (Bluestem seeds, MDOT annual seed mixes
#2: Set up multiple trials of each MDOT seed mix from above as well as bluestem
#3 Label trials as 'normal', wet, dry, and salty (salty represents road salt)
#4 Vary amounts of moisture between the trials as labeled; add 3% saltwater to 'Salty' trials instead of pure water
#5. Observe and record (notes & pictures)
CONSTANT variables; Dates the trials are watered, volume & type of soil and containers, watering technique (except for volume of water & salt), amount of sunlight
Results: Big bluestem was most resistant to negative effects of salt. Tuff Stuff performed well in dry environments. Quick 2 Gro and big bluestem did well in wet environments, but Quick 2 Gro did not do well in the salty or dry environments.
Information: Although the ability of the grass to absorb nitrates is very important for our proposal, we also need to know how well it will survive in environments that aren't ideal. This is especially important in our area because the roads get a lot of salt which effect how long a plant might live. There is also a very wet environment when the snow melts.
Hypothesis: If the survivability of annual seed mixes and perennials such as bluestem are tested in harsh environments, then the perennials will survive better then the annual seed mixes.
Experiment #2 Procedure:
#1: Gather materials (Bluestem seeds, MDOT annual seed mixes
#2: Set up multiple trials of each MDOT seed mix from above as well as bluestem
#3 Label trials as 'normal', wet, dry, and salty (salty represents road salt)
#4 Vary amounts of moisture between the trials as labeled; add 3% saltwater to 'Salty' trials instead of pure water
#5. Observe and record (notes & pictures)
CONSTANT variables; Dates the trials are watered, volume & type of soil and containers, watering technique (except for volume of water & salt), amount of sunlight
Results: Big bluestem was most resistant to negative effects of salt. Tuff Stuff performed well in dry environments. Quick 2 Gro and big bluestem did well in wet environments, but Quick 2 Gro did not do well in the salty or dry environments.