Leguminous plants primarily obtain nitrogen for their growth through a remarkable symbiotic relationship with Rhizobium bacteria.
The Symbiotic Relationship
This beneficial partnership between leguminous plants and Rhizobium bacteria is key to their nitrogen acquisition. Here's how it works:
- Root Nodules: The presence of these special Rhizobium bacteria in the soil stimulates the growth of structures called nodules on the roots of the leguminous plant.
- Nitrogen Fixation: Inside these root nodules, the bacteria perform a vital function. The bacteria help the plant by extracting nitrogen from the air. Atmospheric nitrogen, which plants cannot use directly, is converted into a form the plant can absorb and utilize for growth.
- Mutual Benefit: This is a 'perfect symbiosis'. While the bacteria provide the essential nitrogen to the plant, the plant reciprocates by supplying the bacteria with carbon compounds produced through photosynthesis. This carbon serves as an energy source, helping the bacteria to grow and thrive within the nodules.
This natural process, often referred to as biological nitrogen fixation, allows leguminous plants like beans, peas, lentils, and clover to flourish even in soils with low nitrogen content, reducing the need for synthetic nitrogen fertilizers.
