In agriculture, excessive use of chemical fertilizers leads to many problems. Due to this, organic farming and biofertilizers have become increasingly popular. Recently, a large number of organic fertilizers have started becoming available in the market on a large scale in India. Farmers are continuously using them in their fields. Due to this replenishment of soil nutrients and dependence on chemical fertilizers is also reduced. The use of chemical fertilizers increases the yield, but due to excessive use, the fertility and structure of the soil also have an adverse effect, so the possibilities of using organic fertilizers along with chemical fertilizers are increasing. The use of biofertilizers increases the yield of the soil along with the supply of nutrients to the crop. Bio.SoilZ
For a long time, people were aware that pulses increase the fertility of the soil. After half of the 19th century, scientific evidence for this was presented. Knots are formed for nitrogen fixation in the roots of the plants of the Dahalan family. Paplionidae, Sizzalpinidae, and Mimosidae constitute the subfamilies of the pulse family. 90% of Mimosidae, 23 percent of Sizalpinidae, and 97 percent of Paplionidae have roots that form knots to fix nitrogen.
Microorganisms as organic fertilizers
Biofertilizers are a type of organism that enhance the nutritional quality of the soil. These are the main sources of bacteria, fungi, and cyanobacteria, glands located on the roots of dicot (leguminous) plants are formed by a symbiotic relationship with Rhizobium. These bacteria fix atmospheric nitrogen and convert it into the organic form so that plants can use it as nutrients. Other bacteria (such as Azospirillum and Azotobacter) live freely in the soil. It can also fix atmospheric nitrogen. In this way, the nitrogen content in the soil increases.
Friendly fungi (such as mycorrhiza) form symbiotic relationships with plants. Many members of the genus Glomus form mycorrhiza, in which fungal symbionts absorb phosphorus from the soil and pass it on to plants. Plants derived from such relationships exhibit many other advantages, such as resistance to root-forming pathogens, tolerance to salinity and drought, and increased total growth and development.
Cyanobacteria are autotrophic microorganisms that are widely found in aquatic and terrestrial environments. Many of these can fix atmospheric nitrogen, such as Anabaena, Nosstock, Oscillatoria, etc. Cyanobacteria play the role of important biofertilizers in the paddy field. Blue-green algae also increase organic matter in the soil. Due to this its fertility increases.
Biofertilizer
By using organic fertilizers in crops, nitrogen present in the atmosphere is easily available to the plants (in the form of ammonia), and nutrients like insoluble phosphorus, etc. already present in the soil are converted into a soluble state and easily available to the plants. Since microorganisms are natural, their use increases the fertility of the land and does not have any adverse effect on the environment. Better results can be obtained by using organic fertilizers as a supplement (not as a substitute) to chemical fertilizers.
In fact, organic fertilizers are a mixture of special and any moisture-holding substance. Biofertilizers are prepared by mixing a prescribed quantity of specific micro-organisms in any moisture-holding dusty material (charcoal, lignite, etc.). It is often available in the market under the name of ‘pure culture’ which is a natural product. They can be used for a partial supply of nitrogen and phosphorus in various crops. Their use improves the physical and biological properties of the land and increases its fertility. Organic fertilizers play an important role in organic farming.
The first legume Rhizobium symbiosis was studied in India by Shri NV Joshi, its first commercial production started in the year 1956. During the 9th Five Year Plan of the Government of India, the Ministry of Agriculture started the work of creating awareness among the people along with promoting it in a real way through the National Project for the Use and Development of Biofertilizers.
Types of Organic Fertilizers:
(1) Azolla:
Azolla is a floating fern of the Pteridophyta group. Generally, Azolla is grown in paddy fields or in shallow water. It grows fast. Azolla’s petals contain a microorganism of the genus Anabaena, which fixes atmospheric nitrogen in sunlight and supplies nitrogen to the crop like green manure. The specialty of Azolla is that it becomes twice as big in just 5 days in a favorable environment. If it is allowed to grow throughout the year, more than 300 tonnes of Azolla per hectare can be produced i.e. 40 kg nitrogen per hectare can be obtained. Azolla contains 3.5 percent nitrogen and many types of organic matter which increase the fertility of the soil. With the use of Azolla, it is possible to increase the production of paddy by 5-15 percent.
It can be easily used in paddy fields. In a field filled with 2-4 inches of water, 10 tonnes of fresh Azolla is put before transplanting. Along with this 30-40 kg superphosphate is also sprayed on it. The temperature of 30-35 degrees Celsius is very favorable for its growth.
(2) Blue-green algae:
Blue-green algae (cyanobacteria) are bacteria that produce energy by photosynthesis. Here the bacterium is named cyano (Greek meaning blue) because of the blue color of the bacterium. Cyanobacteria secrete vitamin 12A, auxin, and ascorbic acid which are helpful in the growth of the paddy plants.
Blue-green algae fix atmospheric nitrogen and supply a partial amount of nitrogen to the paddy crop. This organic fertilizer is a cheap and accessible alternative to nitrogen-rich chemical fertilizer, which not only supplies 25-30 kg of nitrogen per hectare to the paddy crop but also improves its quality through the compost made from the remains of blue-green moss in that paddy field. Helps in maintaining fertility.
(3) Azotobacter :
Azotobacter are microscopic heterotrophic bacteria. These are free-living microscopic and aerobic bacteria that freely fixate nitrogen without any symbiosis. It is found only in the rhizosphere. This property is not commonly found in rhizoplanes. The basic secretion, which contains amino acids, sugars, vitamins, and organic acids, helps in the multiplication of Azotobacter. Along with nitrogen fixation, it also secretes plant growth hormone (indole acetic acid and gibberellic acid) and some antibiotics, which have a good effect on the germination of seeds, and a lot of growth in the roots. All diseases are preventable. Azotobacter can be used in all non-pulse crops. Cereal crops, vegetables, cotton, and sugarcane are the main ones. Bjéric was the first to discover and describe the bacteria Azotobacter.
(4) Azospirillum:
This is also a nitrogen-fixing microbe that is beneficial for non-pulse plants. These micro-organisms also aid in biological nitrogen fixation as well as secrete plant growth hormones that are beneficial from germination to plant growth.
(5) Phosphate soluble micro-organisms (PSM) :
These are a group of micro-organisms that convert the insoluble phosphate present in the soil and increase the efficiency of fertilizers. The availability of phosphate is less in alkaline soils. This microbe is very beneficial in reversing the whole process. When PSM is used in conjunction with rock phosphate, the requirement of phosphatic fertilizers can be reduced by about 50% as in single super phosphate. The culture of phosphate soluble bacteria is available in the market under the name PSB culture. This culture is a compound of phosphorus-dissolving bacteria. This increases both production and productivity without polluting, as well as increases the health of the soil.
With the use of PSB, the phosphorus element is easily absorbed by the plants. By using it, a 10-20 percent increase in production and at the same time 30-40 percent phosphorus fertilizer can be saved due to the availability of missing phosphorus in the soil.
It is an essential aerobic, the biologically nitrogen-fixing microorganism that secretes acids through its metabolic activities. All biological nitrogen-fixing micro-organisms fix 78 percent of the nitrogen in the air with the help of an enzyme called nitrogenase through a metabolic process under the common name and pressure. Different types of biological nitrogen-fixing microorganisms have different sensitivities to oxygen. Acetobacter is useful for the cultivation of sugarcane.
(6) Actinorhiza :
The bacteria of the group of actinomycetes that fix nitrogen by forming knots in the roots of the leguminous tree are called actinorhizal. Frankia is a great example of this. Frankia fixes nitrogen in more than 280 tree species of 8 different plant families.
Method of use of organic fertilizers
Seed treatment method: This is the best method of using organic fertilizers, boil a liter of water by mixing about 50 grams of jaggery or gum, after cooling, mix organic fertilizers (200 grams) well and make a solution. This solution is sprinkled on 10 kg of seeds and mixed well so that each seed is coated with it, after that the seeds are dried in a shady place, and sowing of treated seeds should be done immediately after drying.
Plant Root Treatment Method: In rice and vegetable crops whose plants are planted, such as tomato, cauliflower, cabbage, onion, etc., the roots of plants are treated with biofertilizers. For this, in a wide and shallow vessel, make a solution by mixing one kilogram of Azotobacter and one Kriga PSB with 250 grams of jaggery in 5-7 liters of water. After this, after uprooting the plants from the nursery and cleaning the soil in the roots, tie 50-100 in bundles and immerse them in the solution of bacterial fertilizer for 10 minutes.
Tuber Treatment: In crops like sugarcane, potato, ginger, ghuiyan (Taro Root), the tubers are treated with the use of bio-fertilizers. One kilogram of Azotobacter and one kilogram of PSB organic fertilizers are mixed in 20-30 liters of solution. After this, the tubers are immersed for 10 minutes. After that, print it immediately.
Soil Treatment Method: Prepare a mixture of 5-10 kg organic fertilizer and 70-100 kg soil or compost and leave it overnight. Final tillage is performed to mix it in the field.
Benefits of using organic fertilizers
- With their use, there is an increase in the yield of about 10-15 percent.
- It meets up to 20-25 percent of the requirement of chemical fertilizers, especially nitrogen and phosphorus.
- Their use leads to early germination and increases in the number of buds.
- Increases the fertility of the soil.
- Their use increases the amount of sugar in sugarcane, starch in corn and potato, and oil in oilseeds.
Precautions in the use of organic fertilizers:
- Keep the organic fertilizer in a dry place in the shade.
- Choose a bio-fertilizer according to the crop.
- Use the appropriate amount.
- While buying organic fertilizers, check the name of the fertilizer, the date of preparation and the name of the crop, etc. carefully.
- Do not use organic fertilizer after the expiry date.