Microorganisms that increase soil fertility and productivity

Soil fertility is the ability of soil to provide essential nutrients to plants for their growth and development. Soil productivity, on the other hand, is the measure of the amount of plant biomass produced per unit area of soil. Microorganisms play a crucial role in maintaining soil fertility and productivity by decomposing organic matter and fixing atmospheric nitrogen. Among the given options, the group of microorganisms that increase soil fertility along with productivity is:

a) Anabena, Nostoc, and Aulosira

Anabena, Nostoc, and Aulosira are all nitrogen-fixing cyanobacteria. They have the ability to convert atmospheric nitrogen into a usable form that can be taken up by plants. Nitrogen is an essential nutrient for plant growth, and its availability in the soil is often limiting. By fixing nitrogen, these cyanobacteria increase the availability of nitrogen in the soil, which promotes plant growth and productivity. In addition to nitrogen fixation, these cyanobacteria also contribute to soil fertility by:

- Producing organic matter: Cyanobacteria are photosynthetic organisms that produce organic matter through photosynthesis. The organic matter serves as a food source for other microorganisms in the soil, which further contributes to soil fertility.
- Improving soil structure: Cyanobacteria secrete a polysaccharide gel that helps to bind soil particles together. This improves soil structure and stability, which in turn promotes root growth and nutrient uptake by plants.
- Enhancing water retention: The polysaccharide gel secreted by cyanobacteria also helps to retain water in the soil. This is particularly important in dry or arid regions where water availability is a limiting factor for plant growth.

In summary, Anabena, Nostoc, and Aulosira are important microorganisms that contribute to soil fertility and productivity by fixing nitrogen, producing organic matter, improving soil structure, and enhancing water retention.

A