Mr. Hammond has a small garden. He planted tomatoes, zucchini, onion, garlic and beans (legumes). When summer is over and he harvested his crops, why did Mr. Hammond pull out all of the plants except the beans? Those he tilled (mixed) back into the soil for next year's crops. Be sure to explain your answer providing a specific reason.

Beans are the members of the family fabaceae or leguminoceae. The roots of legumes (beans) have root nodules. In the root nodules symbiotic nitrogen fixing bacteria such as Rhizobium is present that fixes atmospheric nitrogen to the soil. No plants can fix atmospheric nitrogen to the soil except nitrogen fixing bacteria. Mr. Hammond tilled (mixed) back beans plants into the soil to get nitrogen fixed in the soil by root nodule bacteria present in beans plants for next year’s crops.