Biofertilizers Definition
Indian economy is an agrarian economy, a reason that makes biofertilisers an essential need for Indian farmers. Though most of our agricultural activities are dependent on monsoon, the use of a good biofertilizer can yield a better crop to the farmers and increase the fertility of the soil. Let’s have a look at biofertilizers’ definition.
Biofertilisers are products that contain microorganisms essential for soil fertility and plant growth when added to the soil. A biofertilizer is a chemical that contains living microorganisms that colonize the rhizosphere or the interior of the plant when given to seeds, plant surfaces, or soil, and encourage growth by controlling the quantity or availability of primary nutrients to the plant host.
Biofertilisers supply nutrients to plants through natural processes such as nitrogen fixation, phosphorus solubilization, and the creation of growth-promoting chemicals. They help restore the soil's natural nutrient cycle and increase soil organic matter.
Healthy plants can be developed with the application of biofertilisers while also improving the soil's sustainability and health. Biofertilisers will likely decrease the need for synthetic fertilizers and pesticides, but they will not be able to completely replace them.
Types of Biofertilisers
Some important types of biofertilisers are as follows:
Symbiotic Nitrogen-Fixing Bacteria
The symbiotic nitrogen-fixing bacteria like Rhizobium get food and shelter from the plants and provide them with fixed nitrogen in return. One of the most important symbiotic nitrogen-fixing bacteria is Rhizobium. Bacteria seek shelter and food from plants here. In exchange, they assist the plants by delivering free nitrogen.
A Loose Association of Nitrogen-Fixing Bacteria
Some bacteria aren’t related directly with the plants but live around them For example, A nitrogen-fixing bacterium called Azospirillum lives near the roots of higher plants but does not form a close bond with them. This is known as rhizosphere association because these bacteria collect plant exudate and use it as food. Associative mutualism is the name given to this phenomenon.
Symbiotic Nitrogen-Fixing Cyanobacteria
There are many symbiotic nitrogen-fixing cyanobacteria like liverworts, cycad roots, the bacteria released by fern plant decay, etc. Cyanobacteria or blue-green algae from a symbiotic relationship with numerous plants. Anabaena can be found in the fern's leaf cavities. It's in charge of nitrogen fixation. The fern plants decompose and release nutrients for the rice plants to use. Azolla pinnata is a fern that grows in rice fields, however, it has no effect on the plant's growth.
Free-Living Nitrogen-Fixing Bacteria
Free-living bacteria are found in soil, and they also perform nitrogen fixation. These include clostridium, azotobacter, and bacillus polymyxin.
They are nitrogen-fixing bacteria that live in free-living soil. Clostridium beijerinckii, Azotobacter, and other saprotrophic anaerobes are among them. Rhizobium and Azospirillum are the most extensively utilized forms of biofertilisers.
Components of Biofertilisers
The components of a biofertilizer are:
Bio Compost: It is eco-friendly and is produced from waste products coming from sugar industry. It also includes bacteria, fungi, and some plants.
Tricho-Card: This eco-friendly non-pathogenic product is useful for many crops and plants, as it plays the role of a productive destroyer against the items that are harmful to the crop.
Azotobacter: It plays an important role in atmospheric nitrogen fixation and protects the plant roots from pathogens in the soil.
Phosphorus: To settle the exact level of need for nitrogen for a plant, and to determine the nitrogen level of the soil, phosphorus fertilizers are very helpful.
Vermicompost: Known for quickly improving soil fertility, these are probably the most eco-friendly fertilizers that contain vitamins, sulphur, hormones, organic carbon, and antibiotics required for the growth of the plant.
Importance of Biofertilisers
There are various uses of biofertilisers that prove their importance. They include – improving the soil quality, protecting the plants from pathogens, avoiding environmental pollution, destruction of harmful substances present in the soil, etc. Thus, biofertilisers are very important.
Applications of Biofertilisers
These are some important applications of biofertilisers:
Seedling Root Dip: Used for rice crops, the seedlings are planted in a waterbed for 8 to 10 hours, in this method.
Seed Treatment: In this process, the seeds are dipped in nitrogen-phosphorus mixed fertilizers. After drying them, they are planted as early as possible.
Soil Treatment: The mixture of biofertilisers and compost fertilizers is kept overnight and spread over the soil the next day. This treatment takes place before sowing the seeds.
Disadvantages of Fertilisers
Chemical fertilizers are supplemented by biofertilisers, not substituted for them.
Biofertilisers only improve crop productivity by 20 to 30 percent. Unlike chemical fertilizers, they do not result in a significant improvement in productivity.
For specific crops, specific fertilizers are necessary. This is more applicable to microorganisms that live in a symbiotic relationship. If non-specific Rhizobium is applied as a fertilizer, root nodulation, and crop production will not rise.
Strict aseptic precautions are required during the manufacture of microbial fertilizer. During microbial mass manufacturing, contamination is a common problem.
Microbes are killed when exposed to sunlight for an extended period of time because they are light-sensitive.
When stored at room temperature, microbial fertilizers must be used within six months, and when stored at chilling temperature, it must be used within two years.
FAQs on Biofertilizers
1. What are Biofertilizers?
Biofertilizers are the fertilizers that contain microorganisms that promote the fertility of the soil and provide a better crop yield when they are added to the soil.
2. Why Should we use Biofertilizers?
Biofertilizers should be used because they provide a dual benefit of increased soil fertility along with a better crop.
3. How can biofertilisers prevent pollution?
Biofertilisers only contain some bacteria, plants, and other biological components that are not at all harmful to the environment. Thus, they can help to reduce pollution (especially soil pollution) caused by agricultural activities.
The use of biofertilisers has been a great hope in Egyptian agriculture, especially in the field of medicinal plants when considering economic and environmental factors, as they reduce environmental pollution and production costs. Biofertilisers protect plants from salt and drought pressure by releasing effective antibiotics from many plant pathogens.
4. Why are biofertilisers more preferable than chemical fertilizers?
Biofertilisers are preferred over chemical fertilizers because they do not contain any harmful chemicals that will increase pollution. They provide many benefits unlike chemical fertilizers, whose overuse can, in turn, reduce the fertility of the land. Another advantage of biofertilisers is their ability to support soil health in contrast to many common fertilizers, which can lead to chemical and toxic imbalances.
The comparison of biofertilisers and chemical fertilizers shows that biofertilisers are cheaper and more cost-effective than chemical fertilizers. Also, they can provide a double benefit by increasing land fertility and providing a better crop yield, which may not be possible in the case of chemical fertilizers. Thus, biofertilisers are more beneficial than chemical fertilizers.
It is said that biofertilisers are very expensive.
Biofertilisers are said to reduce the risk of planting diseases.
The lives of people who eat vegetables grown by applying chemical fertilizers are at great risk.
It is believed that biofertilisers hardly cause any kind of pollution.
Biofertilisers should be used because they provide a dual benefit of increased soil fertility along with a better crop. The combination of growth factors happens due to natural processes of nitrogen fixation, solubilizing phosphorus, and promoting plant growth which is done by adding fertilizers and nutrients.
With the use of biofertilisers, healthy plants can be grown, while improving soil stability and health. Biofertilisers also improve water retention and add essential nutrients such as nitrogen, vitamins, and proteins to the soil. They are a natural type of fertilizer, therefore, they are widely used in agriculture.
5. Are biofertilisers costly?
No, biofertilisers are very cost-effective and affordable for farmers. Some components of biofertilisers like vermicompost can even be made on your own. While you are making an effort to improve soil stability and health, you have to take care of everything to encourage the health of the soil.
6. What are some microorganisms that are present in the biofertilisers?
The following is a list of microbes which is used as biofertilisers:
The free-living bacteria fix the nitrogen like Azotobacter and Rhodospirillum.
The Free-living cyanobacteria fix nitrogen, for example, Anabaena and Nostoc.
Azospirillum makes them the loose association of bacteria which fixes nitrogen.
Symbiotic is a bacterium that fixes nitrogen like Rhizobium and Frankia.
All these microbes are present in the biofertilisers which makes conversion of nitrogen possible which gets assimilated by higher plants.
