define biofertiliser and give eg. of free living bacteria and syano bacteria.
Answers
Answer: Biofertilizers are the biotic organisms which help us to provide nutrients to the concerned crops without using polluting chemicals for they live in association with the crop and provide it with necessary nutrients.
A Biofertiliser (also Bio-fertiliser) is a substance which contains living microorganisms which, when applied to seeds, plant surfaces, or soil, colonise the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant. Biofertilizers add nutrients through the natural processes of nitrogen fixation, solubilizing phosphorus, and stimulating plant growth through the synthesis of growth-promoting substances. Biofertilizers can be expected to reduce the use of synthetic fertilizers and pesticides. The microorganisms in biofertilizers restore the soil's natural nutrient cycle and build soil organic matter. Through the use of biofertilizers, healthy plants can be grown, while enhancing the sustainability and the health of the soil. Since they play several roles, a preferred scientific term for such beneficial bacteria is "plant-growth promoting rhizobacteria" (PGPR). Therefore, they are extremely advantageous in enriching soil fertility and fulfilling plant nutrient requirements by supplying the organic nutrients through microorganism and their byproducts. Hence, biofertilizers do not contain any chemicals which are harmful to the living soil...
Free-living bacterium: Naegleria fowleri
Cyanobacteria: Incertae sedis