A marked increase in environmental awareness and a concern for sustainable agriculture has occurred over the last decade. This awareness has highlighted the need both to further promote plant growth and yields and also to find environmentally benign replacements for industrially produced nitrogen fertilisers.
Agriculturalists have searched for various soil bacteria that might make reliable contributions to the growth of non-legume cereals and have found a group of bacteria which intimately associate with rice. Many of these rice-associating strains are also nitrogen-fixing. Recently Rhizobium bacteria, which normally nodulate legumes, have been shown to associate intimately with the roots of rice plants.