Soil Microbiology- Nitrogen cycle
Main focus question- How do plants obtain usable nitrogen in order to grow and develop?
Background information:
Plants need nitrogen, potassium, and phosphorus in order to develop properly. Plants depend on geochemical cycling to make these elements usable. The major cycle that plants depend on is the nitrogen cycle, which converts nitrogen into nitrates and back to nitrogen. This lesson is a research type lesson using data solely from the www.uwf.edu/usda Growing these bacteria in a school setting is difficult and requires various materials and expensive equipment.
Inquiry Questions-
1. What nutrients are needed by plants and why?
2. How do plants obtain these nutrients?
3. Are there any factors that influence these nutrients?
Student need to know-
The students will need an understanding of the nitrogen cycle. This can be done using a student-based research and/or a teacher-prepared lecture. Students can prepare a project to show understanding.
Project:
Go to Catfish Aquaculture Pond The students will need the soil bacteria data. The bacteria present will show how many nitrogen cycle bacteria are present in each situation. They will also need the biomass information. This will allow them to connect the cycle to plant growth. They will graph the number of colonies present to the biomass of the graph. They will also use the chemical data to compare ammonium levels to nitrate levels at various lengths along the plot.
Questions-
What patterns in bacterial growth are represented in the graphs as distances from the source changes?
Where were most of the nitrogen cycle bacteria found?
How do the populations of various types of nitrogen cycle bacteria vary with distance from the source?
How might these patterns be used to predict the types of nutrients available in the water at different distances as it flows away from the pond? Justify your predictions
Looking at the chemical data for the catfish farm, evaluate your predictions.
How might you explain any variance between the chemical data and the predictions based on microbial populations?
Take on the role of an extension agent. Using the 4-H data, make a recommendation to a farmer on the best management practice for fertilization.
Useful websites
Biosolids- http://www.epa.gov/owm/mtb/biosolids/genqa.htm
Nitrogen cycle- http://helios.bto.ed.ac.uk/bto/microbes/nitrogen.htm
http://www.geog.ouc.bc.ca/physgeog/contents/9s.html
http://wwwfaq.thekrib.com/begin-cycling.html
http://mwextension.missouri.edu/xplor/envqual/wq0252.htm
SSS-
Enviro Marine
D.1.4.2 D.1.4.2
D.2.4.2
D.2.4.10