Biofertilizers Some Facts

1. What is biofertilizer?

Biofertilizers are ready to use live formulates of such beneficial microorganisms which on application to seed, root or soil mobilize the availability of nutrients by their biological activity in particular, and help build up the micro-flora and in turn the soil health in general.

2. Why should we use biofertilizers?

With the introduction of green revolution technologies the modern agriculture is getting more and more dependent upon the steady supply of synthetic inputs (mainly fertilizers), which are products of fossil fuel (coal+ petroleum). Adverse effects are being noticed due to the excessive and imbalanced use of these synthetic inputs. This situation has lead to identifying harmless inputs like biofertilizers. Use of such natural products like biofertilizers in crop cultivation will help in safeguarding the soil health and also the quality of crop products.

3. What are the benefits from using biofertilizers?

• Increase crop yield by 20-30%.
• Replace chemical nitrogen and phosphorus by 25%.
• Stimulate plant growth.
• Activate the soil biologically.
• Restore natural soil fertility.
• Provide protection against drought and some soil borne diseases.

4. What are the advantages of bio-fertilizers?

1. Cost effective.
2. Suppliment to fertilizers.
3. Eco-friendly (Friendly with nature).
4. Reduces the costs towards fertilizers use, especially regarding nitrogen and phosphorus.

5. What types of biofertilizers are available?

1. For Nitrogen
• Rhizobium for legume crops.
• Azotobacter/Azospirillum for non legume crops.
• Acetobacter for sugarcane only.
• Blue –Green Algae (BGA) and Azolla for low land paddy.
  
2. For Phosphorous
• Phosphatika for all crops to be applied with Rhizobium, Azotobacter, Azospirillum and Acetobacter
3. For enriched compost
• Cellulolytic fungal culture
• Phosphotika and Azotobacter culture

6. What biofertilizers are recommended for crops?

• Rhizobium + Phosphotika at 200 gm each per 10 kg of seed as seed treatment are recommended for pulses such as pigeonpea, green gram, black gram, cowpea etc, groundnut and soybean.
• Azotobacter + Phosphotika at 200 gm each per 10 kg of seed as seed treatment are useful for wheat, sorghum, maize, cotton, mustard etc.
• For transplanted rice, the recommendation is to dip the roots of seedlings for 8 to 10 hours in a solution of Azospirillum + Phosphotika at 5 kg each per ha.

7. How biofertilizers are applied to crops?

1. Seed treatment:
   200 g of nitrogenous biofertilizer and 200 g of Phosphotika are suspended in 300-400 ml of water and mixed thoroughly. Ten kg seeds are treated with this paste and dried in shade. The treated seeds have to be sown as soon as possible.
2. Seedling root dip:
   For rice crop, a bed is made in the field and filled with water. Recommended biofertilizers are mixed in this water and the roots of seedlings are dipped for 8-10 hrs.
3. Soil treatment:
   4 kg each of the recommended biofertilizers are mixed in 200 kg of compost and kept overnight. This mixture is incorporated in the soil at the time of sowing or planting.

8. How could one get good response to biofertilizer application?

• Biofertilizer product must contain good effective strain in appropriate population and should be free from contaminating microorganisms.
• Select right combination of biofertilizers and use before expiry date.
• Use suggested method of application and apply at appropriate time as per the information provided on the label.
• For seed treatment adequate adhesive should be used for better results.
• For problematic soils use corrective methods like lime or gypsum pelleting of seeds or correction of soil pH by use of lime.
• Ensure the supply of phosphorus and other nutrients.

9. What would be probable reasons for not getting response from the application of biofertilizers?

1. On account of quality of product
   • Use of ineffective strain.
   • Insufficient population of microorganisms.
   • High level of contaminants.
2. On account of inadequate storage facilities
• May have been exposed to high temperature.
• May have been stored in hostile conditions.
3. On account of usage
• Not used by recommended method in appropriate doses.
• Poor quality adhesive.
• Used with strong doses of plant protection chemicals.
4. On account of soil and environment
• High soil temperature or low soil moisture.
• Acidity or alkalinity in soil.
• Poor availability of phosphorous and molybdenum.
• Presence of high native population or presence of bacteriophages.

10. What precautions one should take for using biofertilizers?

• Biofertilizer packets need to be stored in cool and dry place away from direct sunlight and heat.
• Right combinations of biofertilizers have to be used.
• As Rhizobium is crop specific, one should use for the specified crop only.
• Other chemicals should not be mixed with the biofertilizers.
• While purchasing one should ensure that each packet is provided with necessary information like name of the product, name of the crop for which intended, name and address of the manufacturer, date of manufacture, date of expiry, batch number and instructions for use.
• The packet has to be used before its expiry, only for the specified crop and by the recommended method of application.
• Biofertilizers are live product and require care in the storage
• Both nitrogenous and phosphatic biofertilizers are to be used to get the best results.
• It is important to use biofertilizers along with chemical fertilizers and organic manures.
• Biofertilizers are not replacement of fertilizers but can supplement plant nutrient requirements.
  
• New technique in Biofertilizer

• Generally biofertilizers are carrier based and always in powder form. The carrier is mostly lignite, which has high organic matter content, and it holds more than 200% water, which enhances the growth of the micro-organisms. Before use slurry is made which is applied to seed. This method is universal unless it has some difficulty in application to seed no other method is used.

  Recently university of agricultural sciences, Bangalore has developed a method- dry complex fertilizer for direct soil application. This method consists of granules (1-2 mm) made from tank bed clay (TBC). These granules are baked at 200⁰C in a muffle furnace, which helps to sterilize the material and gives porosity to granules. The baked granules are soaked in a suspension of nitrogen fixing bacteria grown in a suitable medium overnight. The clay granules are air dried at room temperature under aseptic conditions. The granules contain more than a billion of bacteria per gram of granules. These granules are suitable for field application along with seeds and fertilizers in furrows. However, quantity of biofertilizer to be applied will be slightly higher than seed application.