What is Biofertilizer, how are Microbes act as Biofertilizer

What is Biofertilizer, how are Microbes act as Biofertilizer

• Biofertilizers are microorganisms that are introduced to soil or plant surfaces or sometimes in internal organs to the plant. 

• These Biofertilizers help to enhance the growth of plants by providing essential nutrition. 

• Biofertilizer increases the nutrient quality of soil and helps for proper conduction of metabolic function of plants. 

• Bacteria, fungi, Algae etc are predominantly used as biofertilizers.

Bacteria used as Biofertilizers

• Some nitrogen fixation bacteria like Rhizobium reside as symbiotic relationships with the roots of legume plants and form root nodules. 

• These root nodules are reddish in colour due to presence of a pigment leghaemoglobin. This interaction is beneficial for both bacteria and plants. 

• Bacteria provide nitrogen to plants by the fixation from the atmosphere by the processes of biological nitrogen fixation. In turn , plants provide carbohydrates to bacteria by the photosynthesis activity .  

• The oxidation of carbohydrates releases electrons and these electrons are used by bacteria for the reduction of nitrogen. As a result, nitrogen is converted into ammonium ions.

• These ammonium ions are used in formation of amino acids that later on form proteins therefore legumes plants are rich in protein.

• Azotobacterial and azospirillum are also free living bacteria. They also absorb nitrogen from soil and atmosphere and provide to plants.

• Another bacteria was reported by johanna dobereiner as biofertilizer.

• This bacteria is Azospirillum  lipoferum in certain crops like rice, sorghum maize etc.

• These bacteria also increases  the fertility of soil. Diazotrophs like Herbaspirillum, Acetobacter etc also present as free living and provide nutrition to crops of Sugarcane and Rice

Algae used as Biofertilizers

• Azolla, Anabaena, Oscillatoria,Nostoc, Plectonema  etc are blue green algae. 

• They are autotrophic microbes These algae also fix atmospheric nitrogen and provide to plants . 

• Algae store this nitrogen in leaf of plants. They have capacity to fix atmospheric nitrogen and provide it to the plants.

• In the Paddy field, cyanobacteria are important fertilizers. They produce growth stimulators substances which enhance the growth of seedling of rice.

Fungi used as Biofertilizer

• Fungi like Gigaspora, Glomus Sclerocystis make symbiotic relationships with the root of the higher plant.

• These fungi are present in the cortex of the root of the high plant and make a special morphological feature called vesicular arbuscular. 

• The fungi that are present in the vesicular arbuscular region are called vesicular arbuscular mycorrhizal. (VAM) fungi.

• These fungi provide phosphorus  and copper to plants.VAM fungi are gifts of nature for human beings. 

• Another fungi, Frankia, is also used as a biofertilizer mostly found in temperate forest ecosystems. These fungi also form nodules in plants.