In order to make agriculture sustainable and economically viable, there is a need to give a new twist to the traditional farming system. Chemical fertilizers used in agriculture mainly urea, DAP, ammonium sulphate, super phosphate etc. are very expensive despite subsidy and not every farmer can afford to use them. Moreover, the uniform use of chemical fertilizers gradually reduces the productivity of the soil. In such circumstances organic fertilizers must be used as supplements.
There are many types of microorganisms living in the soil, which are very useful for plants. Such microbes help to fix free nitrogen in the air, convert soluble phosphorus in the soil into available forms, or rapidly decompose organic matter. The product of all these types of microorganisms is commonly called as bio-fertilizer. Rhizobium, Azotobacter, Azospirillum, Phosphobacteria, Blue Green Algae and Azolla have been extensively researched in various organic fertilizers. Species with special ability to fix nitrogen or make phosphorus available from the air are isolated, grown on a large scale in the laboratory, mixed with a suitable carrier and sold in packets. One packet available in the market weighs 200-250 grams. In which there are 107 to 108 living organisms in each gram carrier. Under normal circumstances, one gram of organic fertilizer is enough to cover 20-30 grams of seeds. Gujarat Agricultural University after long research has come out with recommendations of different types of organic fertilizers which if used properly can save chemical fertilizers. Organic fertilizers are very innocuous, relatively cheap and pollution free and it is necessary for every farmer to include them in his farming system.
Nitrogen fixing organic manures:
Rhizobium: Leguminous crops such as beans, chickpeas, mung beans, groundnuts, soybeans etc. get most of the nitrogen they need from the air with the help of rhizobium bacteria by forming numerous small root nodules on their roots
Each nodule is a small nitrogen-fixing factory. Generally, pulses require 50 to 60 kg to produce one ton of grain. Nitrogen element is required. But it is our experience that only 20-25 kg per hectare for pulse crops. Nitrogen fertilizer is recommended. Naturally, the question arises, where does the plant get so much nitrogen? Under favorable conditions, 15 days after sowing, small red nodules begin to form on the roots with the help of Rhizobium bacteria and at that time the process of nitrogen fixation begins. which is maximum at the time of seed germination.
In our country, 340 lakh hectares of pulses are cultivated. Which is one fifth of the total plantation (1700 lakh hectares). Rhizobium bacteria are very important in these circumstances. In soils where the amount of resident Rhizobium bacteria is less than 100 cells per gram, the use of Rhizobium bio-fertilizer gives very good results. But in soils where leguminous crops are grown infrequently, the natural rhizobium bacterium is more numerous, so the use of bio-fertilizers often does not make a visible difference. Also, seeing nodules on the roots of leguminous crops does not necessarily mean that the crop is getting enough nitrogen. Each leguminous crop requires the presence of a specific Rhizobium bacterium.
Many Rhizobium organisms in the soil are killed by high summer temperatures, waterlogging of the field, and other predatory pests and viruses. As a result their number in the soil decreases. This is why it is necessary to apply a layer of suitable effective rhizobium bio-fertilizer to the seeds before planting each leguminous crop, so that the crop gets maximum benefits.
20 kg per hectare by using recommended Rhizobium culture of good variety. Nitrogen equivalent yield of pulses is obtained. 100 to 300 kg of leguminous crop with the help of rhizobium. Nitrogen can be fixed per year. And also provides good nitrogen to other crops. This organic fertilizer fulfills 80 percent nitrogen requirement of leguminous crops. It also increases the production of pulses by 10 to 25 percent