| Explore | Through our introductory project where we tested different types of mediums and how much leachate is produced for each, we discovered that the denser the soil, the less leachate is produced and vise versa. We have read about the different methods of asexual plant propagation, such as the use of cuttings, tissue culture, etc. What are other methods of asexual plant propagation? APA Citations for Our Sources: Daugherty, E. (2007). 10.1. In Biotechnology science for the new millenium. Saint Paul, MN: Paradigm Publ. Moody, C., & Townsend, T. (2016, October 11). A comparison of landfill leachates based on waste composition. Retrieved October 05, 2020, from https://www.sciencedirect.com/science/article/abs/pii/S0956053X16305232 Pan, S., Liu, H., Mo, Z., Patterson, B., Duan, M., Tian, H., Hu, S., & Tang, X. (2016). Effects of Nitrogen and Shading on Root Morphologies, Nutrient Accumulation, and Photosynthetic Parameters in Different Rice Genotypes. Scientific reports, 6, 32148. https://doi.org/10.1038/srep32148 |
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| Research Question | We want to study the effects of different levels of nitrogen in a medium on the plant growth of radishes (Raphanus sativus). We researched the effects of nitrogen on different taproots and developed the temporary research question: How do different concentrations of nitrogen in different mediums affect the growth of Raphanus sativus? This question fits into our research on taproots and nitrogen since we already have access to radish seeds and a nitrate testing kit. |
| Predictions | What does the method measure? We are measuring the concentrations of nitrogen in the soil and radish growth. What am I comparing? We are comparing radish growth, based on the nitrogen concentration. What are the possible outcomes? The radish growth will vary depending on the concentration of nitrogen in the soil. For instance, the radish may grow the most in the soil with the highest concentration of nitrogen; the radish may grow the least in the soil with the highest concentration; or, as the concentration of nitrogen in the soil increases, the radish will grow to a certain extent, and at a certain point the growth will plateau/decay. How does the method work? A nitrogen testing kit will be used to measure the nitrogen concentration in each of the mediums. Each concentration will be categorized into low, medium, and high. The radish in the potting soil will be the control group. During the two weeks after planting, the water and time in sunlight will be held constant for all pots. After two weeks, the growth of the radish stems will be measured in each of the pots. What causes the effect I'm seeing? The nitrogen concentrations in the soil will cause the effects of radish growth seen in the experiment. What do I think is going on in my research topic? The varying nitrogen concentrations in the different types of soil will affect the way the radishes end up growing. How does germination (or photosynthesis) work in the light? Or under the conditions I'm testing? Germination and photosynthesis need light in order to occur. The differing levels of nitrogen in the different soils may affect the development of the radish seeds. |
| Experimental Design | What is our plan? Our plan is to test our hypothesis using the procedure found on the next page. What variables will we test? We will test nitrate levels in each of the mediums (using a nitrate testing kit). What variables will we measure and observe? We will measure and observe the size of the radish. What variables will we keep constant? The growth time, amount of sunlight, the amount of medium, the amount of water, and the nitrogen levels in our positive and negative controls, potting soil and sand respectively, will be kept constant. How will we record our data? Most of our data will be qualitative since the nitrate test kit only gives qualitative results, but we will measure the diameter of the radish bulb at the end of the experiment. We will put our data into a google spreadsheet to share results and compare data from the different samples. Hypothesis The radish grown in Sample 2 will grow the most at the end of our experiment. Materials 5 test tubes with caps Water Pipettes Nitrate test kit 3 samples of soil Permanent marker Plastic pots Potting soil (positive control medium) Soil (negative control medium) Ruler Tape Procedure Label the test tubes with names of medium (potting soil, sand, soil sample 1, soil sample 2, and soil sample 3) Label the pots with the names of the medium (potting soil, sand, soil sample 1, soil sample 2, and soil sample 3) Collect three soil samples, test the nitrogen levels for each using the nitrate test kit in their respective test tubes, and record the results on a data table. Transfer 1 cup of medium into each respective pot. Plant radish seed(s) in each pot. Make sure the conditions are the same for each sample, by giving the same amount of water and sunlight. After three weeks of growth, measure the diameter of the bulbs in centimeters. Record observations, qualitative data, of each sample. Compare results. |
| Investigation Theme | AFW |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | California Academy of Mathematics and Science |
| Session | Fall 2020 |