Submitted by deepalitewari
Definition: Bio fertilizers are preparations containing micro-organisms, with capability of mobilizing nutritive elements from non usable form to usable form through biological processes.
How do these fertilizers work?
These microbial cultures fix atmospheric nitrogen, helps in phosphate solubilization or producing hormones, vitamins and other growth factors required for plant growth. These are called biological instruments and play a very significant role in the augmenting of the productivity.
Less expensive. Make soil more productive Eco-friendly and sustainable and They do not require non-renewable source of energy for their production
For vegetables Azotobacter and phosphate soubilizers are commonly used bio-fertilizers.
Azotobacter is free-living nitrogen-fixing bacteria, fixing nitrogen equivalent to 25-30kg N/ha. It also produces hormones like Indole Acetic Acid (IAA) and Gibberellins. Vitamins like biotin, folic acid and different B-group are also produced. The application of Azotobacter, supported by judicious use of organic matter, ensures good seed germination, increasing productivity.
These bio-fertilizers play a significant role in solubilizing insoluble phosphate. Around 95-99% of the total soil phosphorus is insoluble which is directly not available to plants. The P-solubilizers containing bacteria or fungi may convert isolable form of phosphate to soluble form by producing organic acids in general. About 15-25% of insoluble phosphate can be solubilized, saving chemical fertilizers significantly. Important micro-organisms are: Bacillus polymyxa, Aspergillus awamori, Penicillium digitatum etc.
The Regional Biofertilizers Development Centre, Nagpur, conducted experiments at farmers' fields during 1997-98. Table 5, given below shows the increase in yield by application of bio-fertilizers in vegetables:
Table5: Yield increase in vegetables at farmers fields at different locations
Increase in yield over untreated (%)
Source: RBDC, VCA Complex, Nagpur (1997-98).
How to apply bio-fertilizers in vegetables:
There are 4 methods for applying bio-fertilizers in vegetables:
Seed treatment, Cut piece/set treatment, Seedling treatment and Soil application
About 200g of bio-fertilizers is required to treat 10-14 kg of seed. Suspend one packet of 200g in approximately 400ml water and mix it thoroughly. Pour this mixture on seeds and mix with hands to obtain uniform coating on each and every seed. Spread the seeds in shade for drying for 10-15 minutes then sow them immediately.
Prepare a culture suspension by mixing 1 kg of culture in 50-60 litres water. The cut pieces of planting material required for 1 acre are kept immersed in the suspension for 10-15 minutes. Then bring out these cut pieces and allow to dry for sometimes before planting. C Cut pieces method is applicable for crops like potato.
Seedling treatment is recommended for tomato, chilli, onion etc. Prepare the suspension by mixing 1 kg of culture in 10-15 litres of water. Get seedlings required for 1 acre and make small bundles of seedlings. Dip the seedlings in the suspension for 15-20 minutes. Transplant these immediately. Generally the ratio of inoculants and water should be 1:10 approximately, i.e. 1 kg packet in 10 litres of water.
Prepare the mixture of 2-3 kg of bio-fertilizer in 40-60 kg of soil/compost. Broadcast the mixture in one acre of land either at sowing time or 24 hr before sowing. The application of phosphate-solubilizers is very common.