Irrigation: Types & Methods | Civil Engineering Optional Notes for UPSC PDF Download

What is Irrigation?

• Irrigation involves the artificial application of water to crops to fulfill their water requirements. It can also serve as a means to supply nutrients to the crops. Sources of water for irrigation include wells, ponds, lakes, canals, tube-wells, and dams.
• Irrigation provides the necessary moisture for growth, development, germination, and other essential functions of crops.
• The frequency, rate, amount, and timing of irrigation vary depending on the crop type, soil characteristics, and seasons. For instance, summer crops typically demand more water compared to winter crops.

Types of Soil

• There are various types of irrigation methods utilized to water crops effectively.
• Modern methods of irrigation can also be explored for efficient water management.

Irrigation Canal

• An irrigation canal is a vital infrastructure used to transport water for agricultural purposes.
• It plays a crucial role in ensuring a consistent water supply to fields for irrigation.
  

Types of Irrigation 

• Surface Irrigation: Water is distributed across the land by gravity without the use of irrigation pumps. For instance, flooding fields with water.
• Localized Irrigation: Water is applied directly to individual plants through a network of pipes under low pressure. An example is drip irrigation systems.
• Sprinkler Irrigation: Water is distributed from a central location using high-pressure sprinklers or moving platforms with sprinklers. Think of garden sprinkler systems.
• Drip Irrigation: Water droplets are delivered near plant roots. This method is efficient but requires more maintenance. For example, drip tape systems in agriculture.
• Centre Pivot Irrigation: Water is distributed in a circular pattern by a sprinkler system moving along a pivot. This is commonly seen in large agricultural fields.
• Sub Irrigation: Water is distributed through a system of pumping stations, gates, ditches, and canals to raise the water table. This is akin to underground irrigation methods.
• Manual Irrigation: This method involves distributing water with watering cans through manual labor. An example is hand-watering garden beds.

Methods of Irrigation

• Traditional Methods
• Modern Methods

Traditional Methods of Irrigation

• In traditional methods, irrigation is manually conducted. Farmers draw water from wells or canals using their physical labor or animals and transport it to their fields. This approach varies in its execution across different geographical regions.
• The primary advantage of traditional methods is their cost-effectiveness. However, they suffer from poor efficiency due to uneven water distribution and significant water loss.
• Various examples of traditional systems include the pulley system, lever system, and chain pump, with the pump system being the most prevalent.

Modern Methods of Irrigation

• Sprinkler system
• Drip system

Sprinkler System

• The sprinkler system evenly disperses water over crops, aiding in uniform water distribution. This method is particularly beneficial in regions experiencing water scarcity.
• This system involves connecting a pump to pipes to create pressure, allowing water to be sprinkled through pipe nozzles.

• In the drip system, water is supplied drop by drop directly at the plant roots using hoses or pipes. This approach is suitable for areas with limited water resources.

Importance of Irrigation

• Insufficient and unpredictable rainfall can have a negative impact on agriculture, often leading to droughts and famines. Irrigation plays a crucial role in boosting productivity, especially in regions with low rainfall.
• Productivity levels on irrigated land are significantly higher compared to non-irrigated land.
• In many parts of India, the timing of the rainy season restricts farmers to a single crop. However, with irrigation systems in place, multiple cropping becomes feasible, allowing for year-round cultivation.
• The introduction of irrigation has enabled cultivation on previously unused fallow land.
• Irrigation serves to stabilize output and yield levels, providing a more consistent agricultural production.
• By enhancing water availability, irrigation contributes to increased farmer income. However, it's essential to practice optimal irrigation as excessive watering can lead to issues like waterlogging, hindering germination and causing root damage.