Question

Why do plants depend on organisms like Nostoc and Rhizobium?

Answer 1

Nostoc improves the texture and stability if the soil aggregates and protects it from floods and dessication. They also help in reducing pollution. They have very important roles in the environment as they help in nutrient cycling.

Rhizobium is a Nitrogen fixing bacteria live in roots of leguminous plants and form root nodules. This is a symbiotic relationship between them. The nitrogen fixing bacteria help in Nitrogen fixation or conversion of atmospheric Nitrogen into forms usable by the plants. Hence they restore the lost nutrition from the soil. Often legumes are grown in fields that have been depleted in their sources of nutrition. Hence they are important in improving the fertility of the soil.