Explain the following :
i. The year 1921 is known as the 'demographic divide'.
ii. The period during the years 1951 - 1981 is often referred to as the period of 'population explosion'.
Despite tank irrigation being a simple form of irrigation, it is not used by all farmers. Explain Why.
i. Today the need to conserve water resources has become greater that ever. Explain.
ii. Mention two steps that need to be undertaken for the conservation of water resources.
Give two demerits of Canal irrigation.
i. The canal waters soaks into the ground leading to water logging.
ii. It take over large agricultural land.
i. What geographical conditions are required for the growth of wheat?
ii. Compare wheat cultivation in India and China - with reference to the varieties grown .