Composition:

Viable Cell Count: CFU 1 X 10⁸ per ml min.

Contamination level: No Contamination at 10⁵ dilutions

pH: 5.0 to 7.5

1. Mechanisms of Potassium Mobilization

Potassium Mobilizing Bacteria (KMB) employ several mechanisms to solubilize potassium from minerals:

• Acidification: KMB secrete organic acids (e.g., citric, oxalic, and gluconic acids) that break down potassium-bearing minerals, releasing potassium ions (K⁺) into the soil solution.
• Production of Exopolysaccharides (EPS): These compounds help form biofilms around mineral particles, facilitating the release of potassium.
• Chelation: Organic acids and siderophores produced by KMB chelate cations like aluminum (Al³⁺) and silicon (Si⁴⁺), which are bound to potassium in minerals, thereby releasing K⁺.
• Enzymatic Activity: Some KMB produce enzymes that degrade mineral structures, making potassium more accessible.

2. Recommendation:

Irrigation:1 litre in one acre

Seed Treatment: Seeds are coated with KMB to promote early root colonization (10 ml per Kg seeds)

Composting: KMB are added to compost to improve potassium content

Saline Soil Reclamation: KMB are effective in improving potassium uptake in salt-affected soils, where sodium (Na⁺) competes with potassium (K⁺) for plant absorption

3. Benefits of Potassium Mobilizing Bacteria

• Improved Nutrient Uptake: KMB enhance the availability of potassium, a vital macronutrient involved in enzyme activation, photosynthesis, and stress tolerance in plants.
• Enhanced Crop Yield: By increasing potassium availability, KMB contribute to better plant growth, higher biomass, and improved crop yields.
• Stress Tolerance: KMB help plants cope with abiotic stresses like salinity and drought by maintaining optimal cytosolic K⁺/Na⁺ ratios and improving osmotic regulation.
• Sustainable Agriculture: KMB reduce the dependency on chemical fertilizers, promoting eco-friendly and cost-effective farming practices.

4. Applications in Agriculture

• Biofertilizers: KMB are used as biofertilizers to supplement potassium in crops like rice, wheat, and maize, especially in potassium-deficient soils.
• Soil Amendment: They are applied alongside rock minerals (e.g., feldspar and mica) to enhance potassium availability over time.
• Saline Soil Reclamation: KMB are effective in improving potassium uptake in salt-affected soils, where sodium (Na⁺) competes with potassium (K⁺) for plant absorption.

5. Key Genera of Potassium Mobilizing Bacteria

Some of the most studied KMB include:

• Bacillus: Known for its ability to solubilize potassium from minerals like mica and feldspar.
• Pseudomonas: Produces organic acids and siderophores to release potassium.
• Enterobacter: Effective in solubilizing potassium under saline conditions.
• Paenibacillus: Known for its role in potassium solubilization and plant growth promotion.

Conclusion: Potassium Mobilizing Bacteria are a promising tool for sustainable agriculture, offering a natural solution to potassium deficiency in soils. By improving nutrient availability, enhancing crop yields, and mitigating environmental stress, KMB contribute to the goals of eco-friendly and efficient farming. Future research should focus on optimizing their application and understanding their interactions with other soil microorganisms for broader agricultural benefits.