BIO-FERTILIZERS
Biofertilisers are organisms that enrich the nutrient quality of soil. The main sources of biofertilisers are bacteria, fungi, and cynobacteria (blue-green algae). The most striking relationship that these have with plants is symbiosis, in which the partners derive benefits from each other.
Cultured micro-organisms which enrich the soil with nutrients function as biofertilisers. It can be certain strains of bacteria, algae or fungi.
Biofertilisers are good source for enhancing the nutrient availability in soil and plants. These are categorized on basis of the specific nutrient availability concern.
Nitrogenous Biofertilisers are capable of fixing atmospheric nitrogen when suitable crops are inoculated with them. Biofertilisers are low cost, effective,environmental friendly and renewable source of plant nutrients to supplement fertilisers. Integration of chemical, organic and biological sources of plant nutrients and their management is necessary for maintaining soil health for sustainable agriculture. The bacterial organisms present in the biofertiliser either fix atmospheric nitrogen or solubilise insoluble forms of soil nutrients.
- nitrogen fixing biofertilisers (Rhizobium, Azotobacter, Acetobacter),
- Phosphate Solubilising Bacteria (PSB) for phosphorus,
- Potassium Mobilizing Biofertiliser (KMB) for potassium,
- Zinc Solubilizing Biofertiliser (ZSB) for zinc and NPK liquid consortia for nitrogen, phosphorus & potassium.
Types
Biofertilisers will help solve such problems as increased salinity of the soil and chemical run-offs from the agricultural fields. Thus, biofertilizers are important if we are to ensure a healthy future for the generations to come.
Mycorrhiza
Mycorrhizae are a group of fungi that include a number of types based on the different structures formed inside or outside the root. These fungi grow on the roots of these plants. In fact, seedlings that have mycorrhizal fungi growing on their roots survive better after transplantation and grow faster. The fungal symbiont gets shelter and food from the plant which, in turn, acquires an array of benefits such as better uptake of phosphorus, salinity and drought tolerance, maintenance of water balance, and overall increase in plant growth and development.
Legume-rhizobium relationship
Leguminous plants require high quantities of nitrogen compared to other plants. Nitrogen is
an inert gas and its uptake is possible only in fixed form, which is facilitated by the rhizobium
bacteria present in the nodules of the root system. The bacterium lives in the soil to form root
nodules (i.e. outgrowth on roots) in plants such as beans, gram, groundnut, and soybean.
Blue-green algae
Blue-green algae are considered the simplest, living autotrophic plants, i.e. organisms capable of building up food materials from inorganic matter. They are microscopic. Blue-green algae are widely distributed in the aquatic environment. Some of them are responsible for water blooms in stagnant water. They adapt to extreme weather conditions and are found in snow and in hot springs, where the water is 85 °C.Certain blue-green algae live intimately with other organisms in a symbiotic relationship. Some are associated with the fungi in form of lichens. The ability of blue-green algae to photosynthesize food and fix atmospheric nitrogen accounts for their symbiotic associations and also for their presence in paddy fields.
Galaxy of Biofertilisers
- Rhizo: Rhizo Bacterial plays a very important role in agriculture by inducing nitrogen fixings nodules on the root of legumes such as peas,beans clove and alfalfa.
- Azotobactor: Atmosphere contains 78% nitrogen which is a very important nutrient for plant growth. Azotobactor fixes the atmospheric nitrogen in the soil and make it available to the plants. It protects the roots from other pathogens present in the soil.
- Trichoderma: It is a non- pathogenic and eco-friendly product. The product is antagonistic hyper parasitic against different pathogens in the field and economically well established biocontrol agent.
- Tricho-Card: Trichogramma is an efficient destroyer of eggs of many leaf and flower eaters, stems, fruit, shoot borers etc. It can be used in a variety of crops as well as in horticultural and ornamental plants,such as sugarcane, cotton, brinjal, tomato, corn, jawar, vegetables, citrus, paddy apple etc.
- Vermi Compost: It is 100% pure eco-friendly organic fertilizer. This organic fertilizer has nitrogen phosphorus, potassium, organic carbon, sulphur, hormones, vitamins, enzymes and antibiotics which helps to improve the quality and quantity of yield. It is observed that due to continuous misuse of chemical fertiliser soil losses its fertility and gets salty day by day. To overcome such problems natural farming is the only remedy and Vermi compost is the best solution.
- Biocompost: It is eco-friendly organic fertilizer which is prepared from the sugar industry waste material which is decomposed and enriched of with various plants and human friendly bacteria and fungi. Biocompost consists of nitrogen, phosphate solubilizing bacteria and various useful fungi like decomposing fungi, trichoderma viridea which protects the plants from various soil borne disease and also help to increase soil fertility which results to a good quality product to the farmers.
Advantages of Biofertilisers
- Do not cause any pollution in environment.
- Do not destroy other microorganisms in soil.
- Do not turn soil acidic or alkaline.
- Do not contribute to soil erosion by breaking of soil structures.
- These are renewable and cost effective in long run.
Limitations
- Biofertilisers are not developed to a stage, where it can be mass produced.
- Can be an alternative to chemical fertilizers not replacement.
- Is limited to certain crops under specific soil conditions.
Suitability
- Rhizobium is suitable in legume oil seeds such as groundnuts, etc.
- Blue-Green Algae-in wetland rice cultivation..
- Azotobacter can be used with crops like wheat, maize, mustard, cotton, potato and other vegetable crops