N-biofertilizer
Nitrogen (N) is one of the most essential nutrients for plant growth as it has a fundamental role in energy metabolism and protein synthesis. Ammonium and nitrate are two available forms of N for plants. However, chemically produced ammonium (urea as amide form) is a much expensive and energy-intensive process and also poses various threats to the environment, human, and soil health. N-biofertilizer (a formulation of N-fixing microbes) is one of the better options to supplement the chemically produced N-fertilizer. Some microbes have the ability to fix atmospheric N into ammonium and these microbes are called N-fixing microbes. Example: Blue-green algae (BGA, cyanobacteria), BGA associated with Azolla, Azotobacter, Azospirillum, Pseudomonas, Rhizobium, Actinobacteria, etc.
Azospirillum + PSB are major N-biofertilizers used in ginger crops mainly in the form of soil and seed treatments.