biofertilisation

Biofertilisation is the use of living microorganisms or their products to increase the availability of nutrients to plants or to promote plant growth. It encompasses the application of biofertilizers, microbial inoculants, and other biologically active preparations to seeds, planting material, soil, or the root zone.

Microorganisms involved include nitrogen-fixing bacteria, phosphate-solubilizing bacteria and fungi, and plant growth-promoting rhizobacteria. Diazotrophic organisms such as Rhizobium, Azospirillum, and Azotobacter can convert atmospheric nitrogen into forms usable by plants, often in association with legume roots. Phosphate-solubilizing microbes release bound phosphorus from insoluble compounds, improving phosphorus availability. Mycorrhizal fungi form symbiotic networks that extend the effective root area. Some microbes produce phytohormones, enzymes, or antimicrobial compounds that may enhance growth or suppress soil-borne pathogens.

Common biofertilizers include Rhizobium inoculants for legumes, Azospirillum and Azotobacter for cereals, and phosphate-solubilizing bacteria and arbuscular mycorrhizal fungi. Cyanobacteria such as Nostoc or Anabaena in some rice ecosystems are also used. Biofertiliser products may be formulated as seed treatments, root dips, soil amendments, or liquid suspensions.

Biofertilisation can reduce dependency on chemical fertilizers, improve soil health, and support sustainable nutrient management, particularly when integrated with other practices. Its effectiveness is highly dependent on soil conditions, crop species, climate, and management; performance can be variable. Proper product selection, handling, compatibility with agrochemicals, application timing, and storage are important for effectiveness. It is most commonly used as part of an integrated nutrient management strategy and is widely adopted in organic farming in some regions.