Biofertilizers can be called poor man’s technology. Taking in to account the amount of nutrient supplied, biofertilizers are many times cheaper than chemical fertilizers. There are a number of advantages in using bio-fertilizers. The following are the main among them and are briefly explained. If you have not started to use biofertilizers yet, we are giving you 5 reasons why you should switch to bio-fertilisers
In an experiment conducted in Tamil Nadu, it was found that supplying 25 kg nitrogen by chemical fertilizers costs Rs 180 per hectare whereas blue-green algae cost only Rs 54. If farmers themselves produce the blue-green algae culture, the cost could be reduced further. Other experiments showed that spending Rs 30 in blue green algae application (@ 10 kg per hectare) resulted in an extra yield of paddy worth Rs 500-700. One third of the total recommended dose of nitrogen for paddy crop can be reduced if blue green algae or Azolla biofertilizer is applied. If the algal technology is introduced into even 50% of the rice growing area in India (20 m.ha), it will supply 800 million kg of nitrogen (at the rate of 40 kg/h), which in terms of urea would cost Rs 417.6 crores.
Biofertilizers not only supply nitrogen and phosphorus but also some micronutrients essential for plant growth. Sometimes yield is limited by micronutrients essential for plant growth. Sometimes yield is limited by micronutrients and application of nitrogenous, phosphatic and potassic fertilizer does not improve yield significantly. In this situation the application of bulky biofertilizers like blue green algae and azolla increases yield due to greater supply of micronutrient (nutrients required in minute amounts but essential for plant growth).
Organic matter is the essential component of soil. It serves as an inexhaustible source of nutrients and energy for the plants as well as for useful microorganisms. Organic matter has great impact on the physical and chemical properties of the soil. Azolla and blue green algae produce on an average 8-10 tonnes of biomass per hectare, which adds to the organic matter pool of the soil.
When chemical fertilizers are exclusively and continuously used for a few years, they may create acidity or alkalinity in the soil and deteriorate the quality of the soil. Soil also becomes unresponsive to further use of similar fertilizers. Application of biofertilizers along with chemical fertilizers can avoid this problem to a great extent. Besides, large amount of organic matter supplied by the biofertilizers impart tolerance power (buffering capacity) to the soil against acidity or alkalinity. It also withholds metallic elements from entering the plant roots, thereby reducing harmful effects of pesticides.
Plants also need for their growth and development, some natural complex chemical compounds called hormones in adequate amounts, azotobactor blue green algae and azolla have been found to synthesise growth hormones (e.g. indol acetic acid and vitamin B) which benefit the main crop. Sometimes, biofertilizer application gives significant response even if the soul is already rich in plant nutrients. This occurs due to the supply of growth hormones by biofertilizers to the main crop.