What is irrigation? Describe two methods of irrigation that conserve water.
Hint: In agriculture, cultivation of crops require water, where farmers mainly depend on two types of water, they are rainfall water and irrigation water, rainfall water is the purest water and crops produce without any contamination, but it is very difficult for the farmers to depend on the monsoon rains, so irrigation is the artificial supply of water to the crops.
Complete answer: In order to supply the water to the crops, the rainwater should be preserved whenever rain falls, so that it can be utilized in agriculture. Types of irrigation depend on how water is supplied to the fields. Surface irrigation: Here no mechanical pumps are required, while water is supplied by the gravity of the land surface. Localized irrigation: In this type, water is supplied to the crops under low pressure and pipes are used for supply to each and every plant. Drip irrigation: It is also localized irrigation where water is supplied slowly by drops directly near the roots of plants, so the evaporation is minimized in this method. Sprinkler irrigation: sprinklers are placed at the center of the field and they rotate in all directions, so that water sprinkles to all plants of the crops. Central pivot irrigation: here sprinklers are placed on the wheel like platform and it is used mostly in the flat crops Lateral move irrigation: In this method, water is distributed by pipes which are connected to wheel sprinklers Sub-irrigation: Here water is distributed by raising the water table Manual Irrigation: In this type, water is distributed by the labors to the plants directly.
Note: Type, frequency, rate, and amount of irrigation is dependent and it is different for different types of crops, for example, crops in summer require more water than crops in winter, and also depends on the type of soil.