Azotobacter
Azotobacter is a biofertilizer, it’s a free-living non-symbiotic aerobic nitrogen fixing bacteria found in rhizosphere zone of many plants. Azotobacter produces a variety of growth promoting substances like Indole acetic acid (IAA), gibberellins (GA), Vitamin-B and anti fungal substances. Another important Characteristic of Azotobacter associate with crop improvement is excretion of ammonia in the rhizosphere in presence of root exudate's. It fixes approximately 20-30 kg of biological nitrogen per hector per season
How to apply ?
a. Seed inoculation: :
On the basis of efficiency of Azotobacter, other micro-organisms present in the soil, benefits obtained from biofertilizer and expenditure it has been fixed to use Azotobacter - bio-fertilizer at the rate of 250 g biofertilizer for 10-15 kg. If one knows this proportion then take a definite quantity of seed to be inoculated. The required quantity of fresh biofertilizer is secured and a slurry is made by adding adequate, quantity of water. This slurry is uniformly applied to seed, seed is then dried in shed and sown. Some stickers are used in order to adher biofertilizer to seeds. Viz. Jaggery or gum arebia.
b. Seedling inoculation: :
This method of inoculation is used where seedlings are used to grow the crop. In this method, seedlings required for one acre are inoculated using 4-5 packets (2-2.5 kg). For this, in a bucket adequate quantity of water is taken and biofertilizer from these packets is added to bucket and mixed properly. Roots or seedlings are then dipped in this mixture so as to enable roots to get inoculum. These seedlings are then transplanted e.g. Tomato, Rice, Onion, Cole, Crops, flowers.
c. Self inoculation or tubez inoculation:
In this method 50 litres of water is taken in a drum and 4-5 kg of Azotobacter biofertilizer is added and mixed properly. Sets are required for one acre of land are dipped in this mixture. Potato tubers are dipped in the mixture of biofertilizer and planting is done.
d. Soil application:
This method is mostly used for fruit crops, sugarcane, and trees. At the time of planting fruit tree 20 g of biofertilizer mixed with compost is to be added per sappling, when trees became matured the same quantity of biofertilizer is applied.
In sugarcane after two to three months of planting i.e. before earthing up 5-6 kg of biofertilizer per acre is applied by mixing with compost or soil. Although, Azotobacter fixes nitrogen non-symbiotically, it also fixes atmospheric nitrogen in the rhizospere region i.e. soil around the seedlings or trees. Biofertilizer applied to seed or seedlings bacteria remain around seeds or seedlings and use organic carbon for their metabolism. When seeds are germinated or seedlings set in soil they leave or exude root exudates which become food of these bacteria. They grow on these substances which include sugars, organic acids, amino acids and fix atmospheric nitrogen most efficiently. Nitrogen so fixed by these bacteria becomes available to plants after dead and degradation of bacterial cells.
