A farmer was planting wheat crops in his field. He added nitrogen-rich fertiliser to the soil to get a good yield of crops. In the neighbouring field, another farmer was growing bean crops, but she preferred not to add nitrogen fertiliser to get healthy crops. Can you think of the reasons?
The bean crop farmer did not add nitrogen fertiliser because bean plants are legumes that have a natural partnership with Rhizobium bacteria.
These bacteria live in root nodules of leguminous plants like beans, peas, and lentils.
Rhizobium bacteria trap nitrogen from the air and convert it into a form that plants can use.
This natural nitrogen fixation enriches the soil with nitrogen, making additional fertiliser unnecessary.
Farmers often grow legumes in rotation with other crops to naturally increase soil nitrogen and maintain soil health.
Explanation
Section 2.4.2 of the chapter explains that bacteria like Rhizobium form swollen regions called nodules in the roots of legumes such as beans, peas, and lentils. These bacteria trap nitrogen from the air and make it useful for plants, helping them grow better without chemical fertilisers. This is why farmers grow legumes in rotation with other crops to naturally increase nitrogen in the soil.
Solution Steps
Bean plants are legumes that have a natural partnership with Rhizobium bacteria
Rhizobium bacteria live in root nodules of leguminous plants like beans, peas, and lentils
Rhizobium bacteria trap nitrogen from the air and convert it into a usable form for plants
Natural nitrogen fixation enriches the soil, making additional fertiliser unnecessary
Farmers grow legumes in crop rotation to naturally increase soil nitrogen and maintain soil health