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By altering our procedure, we can experiment different conditions that may alter the nitrogen cycle. Our experiment was based on the effects of water, but one could also try altering the amount of light to see how it effects the nitrogen cycle. Although we know that the bacteria have a direct effect on the nitrogen cycle (due to its role in decomposition), we could probably experiment on the number of bacteria vs. each of the elements in the nitrogen cycle. Also, knowing that protozoa is a main predator of bacteria, it may also be wise to experiment on the effect of high protozoa levels on the nitrogen cycle. Seeing that fungi aid in the process of decomposition, the number of fungi may alter the amount and number of dead matter available to the bacteria. For our particular experiment, we collected initial data by taking a 2cm diameter soil sample 15 cm deep 5 times in each of our 3 sites. We then added a specific amount of water to each 20cm by 20cm plot. After words we covered the plot of soil with a 20 cm by 20 cm sheet of plastic. After twenty-four hours we removed the plastic and took another 2cm diameter soil sample 15 cm deep into the soil in each of our testing areas. We then performed nitrate, nitrate and ammonia tests on all of the soil samples. In addition to the chemical tests we also counted the bacteria levels in the soil.
Our research started with the problem: Will an increase in water to areas in the backwoods with an unhealthy nitrogen cycle bring the nitrogen cycle back to a normal state (defined by the condition of a site with a healthy nitrogen cycle)? We then proceeded to make a hypothesis based on this problem. Our hypothesis; An increase in water to areas in the backwoods with an unhealthy nitrogen cycle back to a normal state. Our research group now had a problem and a hypothesis, what we now needed was to figure out the variables that would effect the outcome of our experiment. The experimental variable is the amount of water, the dependent variables are nitrogen levels (ammonia, nitrate, nitrite). The controls that would effect our experiment are the negative control is the soils samples taken prior to the application of the experimental variable, and the positive control is the number of bacteria. |
