Types, Methods, and Importance of Irrigation (Watering Crops)

Irrigation is the process of watering crops, pastures, and plants using water, which is supplied through pipes, sprinklers, canals, sprays, pumps, and other man-made features, rather than purely relying on rainfall.

In other words, irrigation is a method of an advanced watering system for helping plants grow because it is applied as an alternative to rain-fed farming.

It is also a technique of fulfilling plant or crop water requirements as they need it as an essential resource for growth. At the same time, it aids in providing plants with the nutrients required for development and growth and achieving high yields by enabling the penetration of roots in the dry fields.

Traditionally, water for irrigation can be sourced from dams, lakes, rivers, wells, ponds, reservoirs, canals, or tube wells, among various other sources.

Generally, the time, amount of water required, rate, and watering frequency depend on several factors, including the type of crop, types of soil, and the season.

For instance, crops grown in the summer require a lot more water compared to those grown in the winter. That’s because, during the summer, the evaporation rate is high, so you need to constantly replenish the water supply to keep the plants from wilting.

Irrigation is also applied to areas that are geographically not friendly to growing crops, such as dry regions. It helps grow the plants in areas that would otherwise not support such growth.

Having defined irrigation, this article looks at the types, methods, and importance of irrigation.

Types of Irrigation

Some of the common types of irrigation include:

1. Surface Irrigation

Surface Irrigation System

It is one of the most common types of irrigation as it simply employs gravity to distribute water over a field by following the contour of the land. In surface irrigation, for example, water will flow downhill from an area of higher elevation, reaching all the crops.

It is only applicable if the area or the land has sufficient water and is naturally sloped. Otherwise, it becomes very labor-intensive. It utilizes the furrow system technique, whereby channels are used to direct water down a slope across a paddock where crops or plants are grown – about 1 meter apart.

The best example is rice paddies grown in East Asia. In those areas, the land is dug into terraces, and water flows downhill, allowing each plot of land to be watered.

However, surface irrigation is unsuitable for highly sandy soils with high infiltration, as it can lead to uncontrolled water distribution, resulting in floods and soil erosion. Also, it can only work in areas with an unlimited water supply.

2. Localized Irrigation

For localized irrigation, water is distributed to each plant under low pressure. Tubes or piped networks are used throughout the field, delivering water to each plant.

The aim of this type of irrigation is to only wet a small area, typically the root zone of the plant as water is applied just around the base of the plant. The flow rate of the water is also very low, applied regularly and in small amounts either below or above the soil surface.

The application devices used in localized irrigation include nozzles, perforated pipes, small tubes, nozzles, and orifices, whereas the main components include pressure and flow regulators, main lines, laterals, filtration systems, and distributors. Localized irrigation is touted as highly efficient, up to 90%, owing to its high water-saving attribute.

3. Drip Irrigation

Drip Watering

Drip irrigation, sometimes called trickle irrigation, is a sub-type of localized irrigation, where droplets of water are delivered directly to or near the roots of a plant at a very low flow rate.

It is an effective type of irrigation as it minimizes evaporation and water runoff. It is also very suitable for all types of topography and soils and perfect for areas with limited amounts of water or with high water costs. The pressure needed in drip irrigation is between 0.7 and 1.4 kg/cm2(10 and 20 psi).

4. Sprinkler Irrigation

As the name suggests, sprinklers irrigate in a way that simulates natural rainfall. The system is operated in a way that ensures water is applied uniformly. Overhead high-pressure sprinklers or guns are used to distribute water from a central location in the field, usually by pumping.

The sprinklers could also be attached to moving platforms. In center pivot irrigation, for example, sprinklers are attached to wheeled towers in a circular pattern to spray water overhead the plants, and it is common in flat areas. Sprinkler irrigation can be used to irrigate lawns, golf courses, crops, and landscapes and can be used for agricultural, residential, and industrial purposes.

5. Subsurface Irrigation

In this type of irrigation, the soil’s surface is not made wet. Instead, the water is fed directly to the ground through capillarity to reduce airborne drift and lessen runoff. This way, the water table is raised, making it easier for crops to access the required water.

It uses buried pipes, tubes, or drip tape to provide for the water needs of the crops or plants. Its advantage is that it saves water loss from evaporation and improves crop yields by minimizing disease and weeds.

6. Flood Irrigation

Also known as inundation irrigation, flood irrigation is whereby flooded land conditions are intentionally created, making the soil completely saturated. After this process, naturally occurring rainfall is sufficient for the maturity of the crops.

7. Perennial Irrigation

It is a system of irrigation that relies on a continuous water supply. A canal distribution system takes water from a reservoir or weir to the crops.

Various Methods of Irrigation

Some of the various methods of irrigation include but are not limited to the following:

1. Manual Irrigation

Manual Watering of Plants

This is when water is distributed across the land through manual labor and watering cans. It is an ancient method of watering but is still used, especially in developing countries.

Manual irrigation is cheap but labor-intensive, and its efficiency is poor since water distribution is uneven. Also, with this method, there are high chances of water loss.

2. The Sprinkler System

The Sprinkler System

It is a modern method of irrigation, and it uses sprinklers. A pump is connected to pipes that generate pressure, and water is sprinkled through nozzles. They sprinkle water over the crops like raindrops, helping achieve an even water distribution. It is efficient and serves best in areas with unlimited water.

The sprinklers can be set permanently, temporarily, or mounted on a movable platform. In Libya and Saudi Arabia, for example, sprinkler irrigation is by far the most predominant at 100% and 64%, respectively.

Unfortunately for the system, the water used has to be safe for animals and people, water distribution can be patchy, weeds get as much water as the crop, and soils can easily be eroded if the water pools.

3. The Drip or Trickle System

The Drip or Trickle System

In a drip or trickle system, water is supplied drop by drop, directly to the roots, using a hosepipe. Drip irrigation is considered one of the most efficient irrigation methods as it focuses the water onto the plant itself.

It is also best suited for areas with a water shortage. Drip irrigation can use any type of water, including recycled and non-potable water, on any type of soil and in any climate. It minimizes soil erosion, is energy- and cost-efficient, and mitigates the growth of weeds as the water targets the crop itself.

4. Subsurface Irrigation

This is where irrigation water is applied below the soil subsurface. It can occur naturally or artificially.

For the former, water leaks from the water pipes or channels, moving through the subsoil and irrigating nearby crops.

As for the latter, artificial water channels are provided underground, and water is supplied to the crops through capillary. It is a costly means of irrigation but provides high returns and higher profits.

5. Perennial Irrigation

Perennial Water System

Irrigation water is diverted from a river to the main canal by constructing a diversion weir. This is known as direct irrigation, as the water goes directly to the crops. If a dam is constructed and the water is collected and stored, this is called storage irrigation. Direct irrigation is simple and the most economical form of perennial irrigation.

Importance of Irrigation

Of course, irrigation plays a significant role in plant health and the welfare of the surrounding community. Some of the notable benefits of embracing this practice include:

1. Compensating For When There is no Rainfall

Irrigation kicks in when there is insufficient rainfall or uncertainty about when the rain will fall. Without rain or irrigation as an alternative, the crops are adversely affected, which can lead to a food shortage or crop/plant failure.

2. Increasing the Amount of Cultivatable or Agriculturally Productive Land

Some areas of the world are dry, naturally. Irrigation has been responsible for turning such lands into cultivatable lands. Today, about 18% of the world’s cropland is now irrigated. Irrigation is also responsible for bringing the most out of fallow lands, traditionally left idle after harvest, before the next cultivation season.

3. Helps Meet Food Demands

Meets Food Demand

Expanding irrigated land has made desert ecosystems, such as Jordan and Israel, adopt farming to boost food demands without necessarily depending on rain.

Such areas use groundwater from wells and aquifers and in doing so,they’re able to meet the world’s demand for food by producing food crops such as cereals, potatoes, and vegetables.

Furthermore, countries and regions that practice top-level and large-scale irrigation, are best known for exporting food, which brings an economic advantage to such a region or country.

4. Increased Productivity

Irrigation, by default and in many instances, is employed when rainfall is insufficient. However, it can be applied at any time, even if there is sufficient rainfall to boost crop productivity.

According to a publication by Olayide, Tetteh, and Popoola (2016) on climate-smart agriculture, crop productivity on irrigated land is higher than in the unirrigated areas, which primarily rely on rainfall.

5. Enables Multiple Cropping

In most tropical countries, the rainy seasons are specific, making it impossible to grow multiple crops simultaneously. Moreover, their water requirements differ, and over-irrigation spoils the crop production. Optimum irrigation makes it possible to grow more than one crop at a time in most areas of a country.

6. It is Effective

When crops or plants are watered irregularly and with a mere hosepipe, it is not consistent, and they get just one pass. This means hard-to-reach areas and those that do not experience steady rainfall may not get sufficient water. A well-designed irrigation system delivers even to hard-to-reach land areas by using efficient irrigation systems such as drip irrigation.

7. Defeating and Efficient Nature!

Defeating and Efficient Nature!

We cannot control when it will rain. If it rains during the day and it gets a bit warm, evaporation rates will be high, meaning the crops and the soil will not consume enough water.

Irrigation systems can be set to sprinkle water early in the morning or at night when evaporation levels are low. This saves on the water used and maximizes the moisture required by the crops, flowers, or even the soil itself.

8. Contribution to Economic Growth

Irrigation ensures food production continues, regardless of the season or climatic condition. This means there is continuous income and employment, thereby reducing poverty.

The substantial increase in income achieved through irrigation means the economy can continue to thrive. This is also achieved by the export of food to other regions or countries.


Arjun, N. (n.d.). What is Irrigation? What are the Types of Irrigation?. The Constructor. Retrieved from https://theconstructor.org/water-resources/irrigation-definition-types/37463/

“Irrigation vs. Rain-Fed Agriculture”. (2016). Centers for Disease Control and Prevention. Retrieved from https://www.cdc.gov/healthywater/other/agricultural/types.html

Northeast Region Certified Crop Adviser (NRCCA) Study Resources. (2010). Competency Area 3: Drainage and irrigation AEM. Cornell University. Retrieved from https://nrcca.cals.cornell.edu/soil/CA3/CA0324.php

“The main types of irrigation”. (2018). Farmer’s Weekly. Retrieved from https://www.farmersweekly.co.za/farm-basics/how-to-crop/main-types-irrigation/

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About Rinkesh

A true environmentalist by heart ❤️. Founded Conserve Energy Future with the sole motto of providing helpful information related to our rapidly depleting environment. Unless you strongly believe in Elon Musk‘s idea of making Mars as another habitable planet, do remember that there really is no 'Planet B' in this whole universe.