Nutrient Cycles. Please help.

Question

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. 

Answer 1

Beans and other legumes aid in the nitrogen cycle. Most of the nitrogen on Earth is in the earth's atmosphere as diatomic nitrogen (N₂). Bacteria then fix nitrogen into the soil through a process called nitrogen fixation. It then continues through the nitrogen cycle. Nitrogen is very important to biomolecules as very important molecules such as DNA and protein contain nitrogen. Corn and soy is the most common crop rotation in the US because it also improves soil health.