Give reasons for the following:
Nitrogenous fertilisers are not applied in fields where leguminous crops grow.
Nitrogenous fertilisers are not applied in fields where leguminous crops grow as the roots of leguminous crops contain nitrogen-fixing bacteria such as Rhizobium or Azotobacter, which fix the free nitrogen of the atmosphere into nitrates. Thus nitrogen is already made available to the plants and there is no need to add nitrogenous fertilisers.
Expand the following:
DDT
Elaborate the following :
VAM
(a) Describe the procedure of hybirdisation in plants.
(b) Name the causative agent and the main preventive measure for each of the following diseases:
(i) Amoebiasis
(ii) Rabies
(iii) Pneumonia
(c) What is manure? Explain any two types of manures.
