Azotobacter vinelandii
An important bacterium in agriculture for its role in the nitrogen cycle, Azotobacter vinelandii helps in enriching soil nitrogen content, which is vital for the…
Strength
1 x 10⁸ CFU per gram / 1 x 10⁹ CFU per gram
Benefits
Biocontrol Activity
It exhibits biocontrol activity against various plant pathogens, thereby reducing disease incidence and promoting healthier plant growth.
Production of Growth-Promoting Substances
It produces growth-promoting substances such as vitamins, auxins, and gibberellins, which stimulate plant growth and development.
Nitrogen Fixation
Azotobacter vinelandii converts atmospheric nitrogen into ammonia, which is readily available for plant uptake, thereby enhancing plant growth and reducing the need for nitrogen fertilizers.
Phosphate Solubilization
Azotobacter vinelandii solubilizes insoluble phosphates in the soil, making phosphorus more accessible to plants, thereby improving their nutrient uptake and growth.
FAQ
Q1. Can Azotobacter vinelandii completely replace chemical nitrogen fertilizers?While it significantly reduces nitrogen fertilizer requirements, best results are obtained when integrated with reduced or organic nitrogen sources as part of an integrated nutrient management (INM) strategy.
Q2. In which types of soil does it perform best?It is most effective in well-drained, neutral to slightly alkaline soils. In acidic or saline soils, performance may improve with amendments such as lime, gypsum, or organic matter.
Q3. Can it protect against plant diseases?Yes. A. vinelandii suppresses soil-borne pathogens through the production of siderophores, hydrogen cyanide, and antifungal compounds, providing a natural disease defense mechanism.
Q4. How does it help crops during drought conditions?By enhancing root growth and activating antioxidant defense pathways, it increases water-use efficiency and protects plant cells from oxidative damage, improving overall drought tolerance.
Q5. What is the recommended timing and frequency of application?Initial application should coincide with sowing or transplanting. For high-value or long-duration crops, repeat applications via drip or foliar spray may be carried out every 30–45 days to maintain microbial populations.
Q6. Is it safe for the environment and human health?
Yes. A. vinelandii is a naturally occurring, non-pathogenic bacterium that poses no known risk to humans, animals, or the environment. It aligns with global principles of organic and regenerative agriculture.
Scientific References
Azotobacter vinelandii strains demonstrate high nitrogenase activity, promoting growth in rice through enhanced nitrogen availability and phytohormone production (Christiana et al., 2023).
Field applications of A. vinelandii significantly increased rice yield and promoted root development due to IAA and GA₃ production (Sahoo et al., 2013).
Transgenic A. vinelandii expressing glucose dehydrogenase showed improved mineral phosphate solubilization and sorghum seedling growth (Sashidhar & Podile, 2009).
Native A. vinelandii strains exhibited strong phosphate solubilization under varying environmental conditions, making them ideal for biofertilizer formulations (Nosrati et al., 2014).
A. vinelandii improves drought tolerance in rice by boosting root system development, antioxidant activity, and photosynthetic capacity under stress (Pradhan et al., 2018).
Isolates were found tolerant to high salinity, temperature extremes, and pH variations, supporting their application in diverse agro-ecological zones (Chennappa et al., 2016).
A. vinelandii and related species produce antifungal metabolites, siderophores, and hydrogen cyanide that inhibit pathogens like Fusarium and Alternaria (Gurikar et al., 2016).
Mode of Action
1. Biological Nitrogen Fixation (BNF):A. vinelandii harbors three types of nitrogenases (molybdenum-, vanadium-, and iron-only dependent), allowing it to fix atmospheric nitrogen under varying environmental conditions. It converts inert atmospheric nitrogen (N₂) into ammonium (NH₄⁺), a plant-available form, thus supplementing soil nitrogen levels.
2. Phosphate Solubilization:Releases organic acids (e.g., gluconic, citric acids) which chelate bound phosphates, converting them into soluble forms that are easily absorbed by plant roots. This enhances phosphorus availability, a key limiting nutrient in many soils.
3. Phytohormone Production:Synthesizes plant growth-promoting substances such as:
Auxins: Stimulate lateral root development.
Gibberellins: Promote shoot elongation and seed germination.
Cytokinins: Encourage cell division and leaf expansion.
4. Biocontrol Properties:Produces siderophores that chelate iron, limiting its availability to pathogenic microbes, and secretes antifungal compounds that inhibit common soil-borne pathogens such as Fusarium oxysporum and Sclerotium rolfsii.
5. Stress Tolerance Mechanism:Enhances plant resilience to abiotic stresses through:
Increased antioxidant enzyme activity (e.g., SOD, CAT, POD).
Exopolysaccharide (EPS) production for moisture retention and root protection.
Improvement in photosynthetic efficiency and nutrient uptake under drought and heavy metal stress.
Additional Info
Storage Conditions: Store in a cool (5–25°C), dry place away from direct sunlight. Do not freeze. Keep container tightly sealed after use.
Shelf Life: When stored under recommended conditions, the product remains viable for up to 12 months.
Soil pH Compatibility: Functions best in neutral to slightly alkaline soils (pH 6.8–8.0). In acidic soils, pre-application of lime or incorporation of organic matter may improve efficacy.
Crop Compatibility: Suitable for a broad spectrum of crops including cereals, legumes, vegetables, oilseeds, and plantation crops.
Input Integration: Compatible with organic fertilizers, bio-composts, and other microbial inoculants. Avoid co-application with chemical pesticides unless verified safe.
Dosage & Application
Seed Coating/Seed Treatment: Coat 1 kg of seeds with a slurry mixture of 10 g of Azotobacter Vinelandii and 10 g of crude sugar in sufficient water. Dry the coated seeds in shade before sowing or broadcasting in the field.
Seedling Treatment: Dip seedlings into a mixture of 100 grams of Azotobacter Vinelandii with sufficient water.
Soil Treatment: Mix 3-5 kg per acre of Azotobacter Vinelandii with organic manure or fertilizers. Incorporate into the soil during planting or sowing.
Irrigation: Mix 3 kg per acre of Azotobacter Vinelandii in water and apply through drip lines.
