Question

13. Nitrogen is an essential nutrient for plant growth. But farmers who cultivate pulse
crops like green gram, bengal gram, black gram, etc. do not apply nitrogenous
fertilizers during cultivation. Why?​

Answer 1

Answer:

Nitrogen is an essential nutrient for plant growth. But farmers who cultivate pulse crops like green gram, bengal gram, black gram, etc. do not apply nitrogenous fertilisers during cultivation. It is because some amount of nitrogen is also present in the soil that help the plants grow

Answer 2

these plants come under leguminous plants . to fix atmospheric nitrogen to absorbable form it has symbiotic nitrogen fixing bacteria like rhizobium  this bacteria produces small outgrowth on the surface of roots called as nodule .

division and growth of cortical and pericycle cells lead to nodule formation . a mature nodule is completed with vascular tissues continuous with the root .

the invading bacteria stop dividing stop growing and get modified into rod shaped structure called bacteriods . the nodule contain all the biochemical  compounds required for nitrogen fixation including the enzymes nitrogenase  and a red or pink coloured pigment called leguminous haemoglobin or leg haemoglobin. it is oxygen scavanger.