Legume plants receive nitrogen from Rhizobium which makes them possible to grow in nitrogen poor soil. In return, legume plants supply Rhizobium with carbohydrate, which is energy. This process is called nitrogen fixation, also known as the symbiosis of legume and Rizobium. However, it would be inefficient for plants in nitrogen rich soil to transfer their energy to Rhizobium in exchange of nitrogen when sufficient amount of nitrogen is present. In this situation, plants will not transfer its energy to Rhizobium. This is beneficial to plants in nitrogen rich soil, because it does not have to lose energy. Soybean plants, which are legume plants, are used in this experiment to test the following hypotheses. 1.When soybean plants are planted in nitrogen poor soil, soybean plants will grow larger if they are treated with Rhizobium. 2.When soybean plants are planted in nitrogen rich soil, soybean plants will resist being affected by Rhizobium. 3.When soybean plants are planted in nitrogen rich soil, soybean plants treated with Rhizobium will grow shorter than those that were not.
MATERIALS AND METHODS
To conduct the test, four treatments were applied to soybean seeds and each were labeled –L: Soybeans planted in low nitrogen soil without Rhizobium bacteria +L: Soybeans planted in low nitrogen soil with Rhizobium bacteria -H: Soybeans planted in high nitrogen soil without Rhizobium bacteria +H: Soybeans planted in high nitrogen soil with Rhizobium bacteria
The following steps were taken to run the test. First, two white pots and two green pots were used. White pots were treated with low nitrogen and green pots were treated with high nitrogen. Second, a fertilizer stick is inserted in the green pots 1cm away from the edge, and two holes were made in all four pots. Each hole was no more than 1cm in depth, and each hole were made in the center, 1 cm away from each other. Third,...