Beera, wants to practice crop rotation in his field

Beera, wants to practice crop rotation in his field. Suggest a Rabi crop and a Kharif crop which will replenish his field with nitrogen. Which crop replenishes nitrogen and why?

Answer:
Kharif: Rice or Soyabean
Rabi: Pea or Wheat
Pea/Soyabean are legumes that will fix nitrogen with the help of Rhizobium.