Peanut crop. Rows of peanut or groundnut plants (Arachis hypogaea) growing in a field. Peanuts are grown for human food, animal fodder, and for their oil. The seeds contain about 50% oil and 30% protein, and are a good source of vitamin B & E, and minerals. Peanuts, a type of legume, have Rhizobium sp. bacteria in their roots which help to improve the soil by converting (fixing) atmospheric nitrogen to form nitrate chemicals that are essential plant nutrients. Peanuts are grown around the world in tropical and subtropical countries. Photographed in Queensland, Australia.