Nitrogen fixation in cereals: Current knowledge and future prospects

Nitrogen is a vital element for plant growth, influencing both crop productivity and soil health. In cereal crops, nitrogen is primarily supplied through synthetic fertilizers, which come with a host of challenges, including high costs, inefficiencies, and significant environmental impacts. Biological nitrogen fixation (BNF) has emerged as a promising solution, primarily studied in legumes but also in non-leguminous crops like cereals. This review paper provides an overview of the current knowledge regarding nitrogen fixation in cereals, focusing on the mechanisms involved, recent advancements, and the challenges and prospects of improving nitrogen fixation in major cereal crops like rice, wheat, and maize. It discusses the role of microbial inoculants, genetic engineering, and symbiotic and non-symbiotic nitrogen-fixing bacteria. Moreover, the review highlights the potential of nitrogen fixation to reduce dependency on synthetic nitrogen fertilizers, contributing to more sustainable agricultural practices, particularly in India, where cereal production is a cornerstone of the economy. Finally, the paper explores future prospects, including biotechnology advancements, climate change considerations, and policy support, aiming to improve food security and environmental sustainability.