How do Peanuts & Soybeans return nitrogen to the soil?Why's nitrogen important to a growing plant?

Question

I have this major science project, and I was unable to find clear info on this to help me understand. If someone could answer this for me, it'd be of GREAT help, and i'd appreciate it!

Answer 1

Nitrogen is needed to make amino acids.  Amino acids are needed to make proteins.

Nitrogen is a cycle like the water cycle.

Answer 2

Legumes, which include peanuts and soybeans, have nodules on their roots where nitrogen fixing bacteria live. The bacteria can take nitrogen from the air and make it available to the plants to make amino acids and proteins .Fertilizers that we add to the soil contain nitrogen as well as phosphorus and potassium. It is better to let the bacteria provide the nitrates so runoff does not pollute the streams with excess nutrients.