Biofertilizers are defined as preparations containing living cells or latent cells of efficient strains of microorganisms that help crop plants’ uptake of nutrients by their interactions in the rhizosphere when applied through seed or soil. They accelerate certain microbial processes in the soil which augment the extent of availability of nutrients in a form easily assimilated by plants. Very often microorganisms are not as efficient in natural surroundings as one would expect them to be and therefore artificially multiplied cultures of efficient selected microorganisms play a vital role in accelerating the microbial processes in soil. Use of biofertilizers is one of the important components of integrated nutrient management, as they are cost effective and renewable source of plant nutrients to supplement the chemical fertilizers for sustainable agriculture. Several microorganisms and their association with crop plants are being exploited in the production of biofertilizers. They can be grouped in different ways based on their nature and function.
| Groups | Examples |
| A N2 fixing Biofertilizers | |
| Free-living | Azotobacter, Beijerinkia, Clostridium, Klebsiella, Anabaena, Nostoc, |
| Symbiotic | Rhizobium, Frankia, Anabaena azollae |
| Associative Symbiotic | Azospirillum |
| B P Solubilizing Biofertilizers | |
| Bacteria | Bacillus megaterium var. phosphaticum, Bacillus subtilis, Bacillus circulans, Pseudomonas striata |
| Fungi | Penicillium sp, Aspergillus awamori |
| C P Mobilizing Biofertilizers | |
| Arbuscular mycorrhiza | Glomus sp.,Gigaspora sp.,Acaulospora sp., Scutellospora sp. & Sclerocystis sp. |
| Ectomycorrhiza | Laccaria sp., Pisolithus sp., Boletus sp., Amanita sp. |
| Ericoid mycorrhizae | Pezizella ericae |
| Orchid mycorrhiza | Rhizoctonia solani |
| D Biofertilizers for Micronutrients | |
| Silicate and Zinc solubilizers | Bacillus sp. |
| E Plant Growth Promoting Rhizobacteria | |
| Pseudomonas | Pseudomonas fluorescens |
Biofertiliser production
Biogas installations do not only produce energy but also digestate. This is the residual part of organic matter treated by AD, and is rich in plant available nutrients. The microbial processes which convert biomass into bio-energy, also convert mineral nutrients to more plant available form. When substituting synthetic mineral fertilizer N by mineral nitrogen from biobased renewable sources, GHG emissions can be reduced by up to 6 kg CO2 eq per kg mineral N replaced (FP-7 Improved Nutrient and Energy Management through Anaerobic Digestion ; www.inemad.eu). In the EU-28, current synthetic mineral N use corresponds with 11 million t synthetic N, leaving a huge potential for GHG reduction when moving to a circular approach for mineral N fertilizer use.
Biofertilizers market size and growth prospects
The biofertilizers market is expected to grow at a CAGR of 14.08% from 2016, to reach USD 2,305.5 million by 2022 (See figure below). The market is driven by factors :
i) increasing demand for fertilizers due to the growing food production worlwide
ii) development of new technologies for biofertilizer.
Factors restraining the biofertilizers market are lack of awareness and low adoption of biofertilizers coupled with poor infrastructure.
Global biofertilizers market is expected to growth over the period 2015– 2020 on account of providing physical barrier against pests, pathogens and enhance absorption of zinc and phosphorus. Biofertilizers in agriculture aids the decomposition of organic residues and stimulates overall plant development and growth. Growing demand for high agricultural yield has triggered the use of biofertilizers. Increasing need for organic foods among consumers in expected to have a positive impact on the biofertilizers market over the next 5 to 7 years. Furthermore, rising prices of chemical fertilizer coupled with commercial response to growing food cost is expected to be one of the key drivers for biofertilizers market over the period 2015 – 2020.
Sorce: www.bio-fit.eu
ADVANTAGES
- They help to achieve high yields of crops by enriching the soil with nutrients and useful microorganisms necessary for plant growth.
- They replace the chemical fertilizers, as the latter are not beneficial for plants. Chemical fertilizers decrease the plant growth and pollute the environment by releasing harmful chemicals.
- They are eco-friendly due to the fact that they protect the environment against
Pollutants. - If the soil is free of chemicals, it will retain its fertility, which will be beneficial for
the plants as well as the environment, because the plants will be protected against diseases and the environment will be free of pollutants. - Biofertilizers destroy those harmful components from the soil which cause diseases in plants. By using biofertilizers, plants can also be protected against drought and other restrictive conditions.
- Biofertilizers are cost effective. They are not costly and even low-income farmers
can make use of them.
DISADVANTAGES
- Gives much lower nutrient density – it requires large amounts to get enough for
most crops; - Requires a different type of machinery to apply from that used for chemical
Fertilizers; - Sometimes is hard to locate in certain areas; odour; difficult to store; Specific to the plants;
- Requires skills in production and application.
- There is inadequate awareness about the use and benefits of biofertilizers.