The students involved in the IIT Heritage Garden on campus are preparing to plan for the spring planting season. Some students are wondering how they can enrich the soil with regard to nitrogen supply. You suggest growing peas. They ask why? Explain how peas and their microbial symbionts will take care of the nitrogen issue for free. Some students want to use a rototiller on the soil. You worry that this could disturb the mycorrhizal fungi all ready growing in the soil. The students ask you to explain what you mean, how would you answer them? What type of symbiotic relationship do both of these symbionts have with their plant partner? Explain.