Why the demand of water for irrigation increasing?

Why is irrigation essential ?

Giving reasons, state the following statements are true or false: (i) An increase in the price of Coke would result in decrease in the demand for Pepsi. (ii) An increase in the price of sugar would result in an increase in the demand for tea. An increase in the income of a consumer would result in an increase in demand for all types of goods that are demanded by a consumer.