Sustainable crop production depends much on good soil health. Soil health maintenance warrants optimum combination of organic and inorganic components of the soil. Repeated use of chemical fertilizers destroys soil biota. In nature, there are a number of useful soil micro organisms which can help plants to absorb nutrients. Their utility can be enhanced with human intervention by selecting efficient organisms, culturing them and adding them to soils directly or through seeds. The cultured micro organisms packed in some carrier material for easy application in the field are called bio-fertilisers.
Bio-fertilisers are living microorganisms of bacterial, fungal and algal origin. Their mode of action differs and can be applied alone or in combination. By systematic research, efficient strains are identified to suit to given soil and climatic conditions. Such strains have to be mass multiplied in laboratory and distributed to farmers. They are packed in carrier materials like peat, lignite powder in such a way that they will have sufficient shelf life.
LIST OF COMMONLY PRODUCED BIO-FERTILIZERS IN INDIA
||BENEFITS USUALLY SEEN
||Legumes like pulses, groundnut, soybean
||10-35% yield increase, 50-200 kg N/ha.
||Fodders give better results. Leaves residual N in the soil.
||Soil treatment for non- legume crops including dry land crops
||10-15% yield increase- adds 20-25 kg N/ha
||Also controls certain diseases.
||Non-legumes like maize, barley, oats, sorghum, millet, Sugarcane, rice etc.
||10-20% yield increase
||Fodders give higher/enriches fodder response. Produces growth promoting substances. It can be applied to legumes as co-inoculant
(*there are 2 bacterial and 2 fungal species in this group)
|Soil application for all crops
||5-30% yield increase
||Can be mixed with rock phosphate.
|Blue-green algae and Azolla
||20 -30 kg N/ha, Azolla can give biomass up to 40-50 tonnes and fix 30-100 kg N/ha
||Reduces soil alkalinity, can be used for fishes as feed. They have growth promoting hormonal effects.
TNAU has developed high yielding Azolla hybrids.
||Many trees, some crops, and some ornamental plants
||30-50% yield increase , enhances uptake of P. Zn, S and Water.
||Usually inoculated to seedlings.
Major advantages of Biofertilisers
Biofertilisers enhance the nutrient availability to crop plants (by processes like fixing atmosphere N or dissolving P present in the soil) ; and also impart better health to plants and soil thereby enhancing crop yields in a moderate way. It is a natural method without any problems like salinity and alkalinity, soil erosion etc.. In the vast areas of low input agriculture and oil seeds production, as also in crops like sugarcane, etc, these products will be of much use to give sustainability to production. In view of the priority for the promotion of organic farming and reduction of chemical residues in the environment, special focus has to be given for the production of biofertilisers.
The biofertilisers are mainly purchased by State Agriculture Departments and distributed to the farmers at concessional rates. About 200 to 500 grams of carrier material is only needed per acre, costing about Rs.10/- to 25/-. In view of the above, if the units are selected carefully, there can be assured business. The benefits usually obtained by the use of biofertilizers will not be as visible as that of chemical fertilizers. As the results are not dramatic, many farmers are not aware of the significance, excepting in States like Maharashtra, Gujarat, parts of Karnataka and Tamil Nadu, these are more commonly used with Government's support. In the context of increasing awareness about the use of natural products and organic agriculture, these products will have good scope. Further, the organically grown produces fetch higher prices both in domestic and export markets.
It is estimated that the production of biofertilisers in the country by the existing units is about 7500 to 9000 TPA. This is far below the potential requirement of 7.6 lakh TPA by the year 2000-2001 as estimated by the National Biofertiliser Development Centre (NBDC) Ghaziabad. So far, the Ministry of Agriculture has supported establishment of 67 biofertiliser units in different parts of the country.
Estimated potential Demand for Biofertilisers by 2000-2001
|Type of Biofertiliser
Blue green Algae
Phosphate solublising microorgaanism