Introduction. Microbes as biofertilizers, their types and importance. Rhizobium. Azotobacter. Azospirillum. Acetobacter diazotrophicus. Blue-green algae. Azolla. Frankia: N2-fixing endophytes. Phosphate solubilizing microorganism. Vesicular arbuscular mycorrhizae. Sulphur oxidizing microorganism. Silicate solubilizing biofertilizers. Potassium solubilizing biofertilizers. Composting culture. Production technology of biofertilizers. Assessment of quality standards of biofertilizers. Application technology of biofertilizers. Advantages, limitations and constraints.
