Question

Justify the statement—"legumes fertilise the soil but not the cereals".

Answer 1

Legumes such as peas, soybeans and groundnuts form root nodules containing symbiotic Rhizobium bacteria. These bacteria fix atmospheric nitrogen into forms plants can use, and nitrogen-rich root and plant residues can enrich the soil. Cereal crops generally do not form these Rhizobium-containing nodules, so they do not add nitrogen to the soil in the same way. Cereals can still benefit from free-living nitrogen-fixing microbes in the soil, but they do not have the characteristic legume–Rhizobium symbiosis.