Irrigation: Types, Methods and Significance, Practice Problems and FAQs

You might have seen lawns in front of malls or some hotels. Some of you may have it at home also. It is very nice to walk through the lawns, right? While walking through this lawn, have you ever observed how watering is done here? Yes, you might have seen some black colour wires or sprinklers in between. These are used to provide a proper amount of water to the plants because if we pour more water, the roots will come up due to the removal of surface soil which will lead to the death of the plant.

What would happen if the water supply stops permanently? Yes, then the plants do not get enough water. The pressure inside leaves and stems will drop and they will bend first and slowly they will wilt. This will finally lead to their death. Now you understand that proper watering is important for plants not only to improve the yield but also to maintain them healthy. Water is required for photosynthesis and all metabolic activities in plants.

Fig: Common requirements of a plant

Can you tell me what is the source of water for the crops if the rain is not available? Yes, the water is distributed to the crops by irrigation. Irrigation is the watering of land by artificial means to foster plant growth. Do you know water can be provided to the plants through different methods of irrigation? Let’s discuss all the types and methods of irrigation in this article.

Table of contents

Irrigation
Types of irrigation systems
Methods of irrigation
Significance of irrigation
Practice Problems
FAQs

Irrigation

The human body is composed of nearly 70% of water, whereas the plant body is composed of nearly 90% of water. Irrigation is the process of artificially applying water to crops to meet their water needs. Irrigation can also be used to supply nutrients that are needed by the crops. Wells, ponds, canals, tube wells, and dams are some of the various water sources utilised for irrigation.

GIF: Dam

The moisture required for plant germination, growth, and other related processes is supplied by irrigation. Depending on the crop, the soil type, and the season, different irrigation methods are used. For example, summer crops require more water as compared to winter crops.

Fig: Irrigation

Types of irrigation systems

Depending on the way by which the water is spread in and around the field, there are different types of irrigation systems. Some of the common types of irrigation systems are listed below:

Surface irrigation system
Localised irrigation system
Drip irrigation system
Sprinkler irrigation system
Center pivot irrigation system
Lateral move irrigation system
Sub-irrigation system
Manual irrigation system

Surface irrigation system

In this type of irrigation system, water is distributed over and across the land under the influence of gravity. In surface irrigation, no mechanical pumps are used.

Fig: Surface irrigation system

Types of surface irrigation system

Surface irrigation system is of four types as follows:

Basin irrigation system
Border irrigation system
Furrow irrigation system
Uncontrolled flooding system

Basin irrigation system

It is considered as the most common form of surface irrigation system. It is used in regions with layouts of small fields. Here the field has proper levelling in all directions to prevent runoff. It provides an undirected flow of water into the whole field.

Fig: Basin irrigation system

Border irrigation system

It is considered as an extension of the basin irrigation system. Here normally the field is divided into sloping borders and then the water is applied to individual borders from small hand-dug checks from the main field head ditch. When the water is shut off, it normally moves from the upper ends to the lower ends of the field.

Fig: Border irrigation system

Furrow irrigation system

This irrigation system avoids flooding the entire field surface. Here the water is channelled along the primary direction of the field by using 'creases,' or 'furrows'. Water then infiltrates and spreads to refill the soil reservoir.

Fig: Furrow irrigation system

Uncontrolled flooding system

Here in this irrigation system the croplands are irrigated without uniformity or efficiency. This is normally practised when the crop value is very small or the field is used mainly for recreation or grazing purposes.

Fig: Uncontrolled flooding system

Localised irrigation system

In this type of irrigation system, water is supplied to plants and trees under low pressure via a network of pipes as given below. It is done in a pre planned manner. It includes drip irrigation, porous pipes, perforated plastic sleeves and porous clay pots.

Fig: Localised irrigation system

Drip irrigation system

It is considered as a type of localised irrigation system in which water drops are applied at or near the roots of a plant. It is also called the trickle irrigation system. It involves dripping water into the soil at low rates. It is done with the help of a system of small diameter plastic pipes. These pipes are fitted with small outlets called drippers or emitters. Evaporation and runoff are reduced by using this kind of irrigation. Efficiency of the irrigation system and crop yield can be increased by this method. This is useful in areas with water scarcity.

Fig: Drip irrigation system

Sprinkler irrigation system

In this type of irrigation system, water is distributed to all the plants with the use of sprinklers from a central position. This method looks similar to natural rainfall. Two types of sprinklers are commonly used for this purpose such as high-pressure overhead sprinklers and sprinklers with moving platforms. In this system water flows through a system of pipes by pumping. This water then separated through sprinklers. Sprinklers split up water into tiny water drops that fall on the ground like raindrops.

Fig: Sprinkler irrigation system

Center pivot irrigation system

In this type of irrigation system, water is distributed by a set of sprinklers. These sprinklers move on wheeled towers in a circular pattern. This type of sprinkler system is commonly used in flat areas. It is the most commonly used sprinkler system in the world.

Fig: Center pivot irrigation system

Lateral move irrigation system

In this type of irrigation system, a network of pipes, each with a wheel and a set of sprinklers, is used to distribute water in the agricultural field. These pipes can be rotated by hand or by motors. After the sprinklers have travelled a specific distance across the agricultural field, the water hose must be reconnected in order to cover the subsequent distance. Due to this reason, this irrigation system tends to be less expensive but it requires more labor as compared to other irrigation systems. It is commonly used in rectangular areas.

Fig: Lateral move irrigation system

Sub-irrigation system

In this type of irrigation system through a network of pumping stations, canals, gates, and ditches, water is dispersed. It helps in increasing the water table. It is also called the zero runoff method. It also helps in conserving fertilisers and water. They are commonly used by greenhouse growers. It allows uniform growth, improves the product quality, and increases production. In regions with high water tables, this form of irrigation is most efficient.

Fig: Sub-irrigation system in greenhouse

Manual irrigation system

In this type of irrigation system through manual effort using hose or watering cans, water is dispersed over the land. Therefore, this method is very labor intensive. It is also less efficient. This is the most commonly used method. It is useful for small areas.

Fig: Manual irrigation system

Methods of irrigation

There are two types of irrigation methods that are commonly used as follows:

Traditional irrigation methods
Modern irrigation methods

Traditional irrigation methods

Traditional irrigation methods are the most time-tested and have been in use for a long time. They are also more cost-effective and effective than modern methods. Some of these irrigation methods are still used. The traditional methods of irrigation are further categorised into four types as follows:

Check basin method
Furrow irrigation method
Strip irrigation method
Basin irrigation method

Fig: Traditional irrigation method

Check basin method

For levelled fields, the check basin method is one of the best methods of irrigation. The field is separated into basins based on its ability to hold water here. A small drain connects the several basins. The size of the basin depends on the water inflow. The primary water source is located at the top of the field. There are no technical requirements for this procedure. Additionally, it is cost-effective. As the precipitation remains in the basin, it stops soil erosion. This technique effectively irrigates a huge region.

Fig: Check basin method

Furrow irrigation method

This irrigation method is used in areas where the crops are grown in rows. Water flows between two ‘Dols’ which are formed along the sides of the rows. There is no need to supply water once the furrow is filled. Although this method of irrigation is inexpensive, it requires a lot of labor. This technology uses a significant amount of water to provide food crops grown over broad regions.

Fig: Furrow irrigation method

Strip irrigation method

In this type of irrigation method, the fields are divided into several strips of different sizes. The strips are built in accordance with the slope. The size of the strips are decided based on the topography of the land. It is a simple irrigation technique that requires minimal work.

Fig: Strip irrigation method

Basin irrigation method

In this type of irrigation method, around the plants and trees, an elevated platform has been built. These platforms are then attached to the drains. This technique works well for watering trees and bushes but it is not recommended for agricultural crops. However, using this method wastes a lot of water.

Fig: Basin irrigation method

Advantages of traditional irrigation methods

The following are the major advantages of traditional irrigation methods

Traditional irrigation methods are useful in leveled crop fields.
Technical knowledge is not required to use them.
These methods allow rain water to stay in basins. This normally prevents soil erosion.
It is useful in soils with lesser infiltration.
Economic investment is less here and hence it is affordable to the farmers.
It will cover more area for irrigation.

Disadvantages of traditional irrigation methods

The following are the major disadvantages of traditional irrigation methods:

In order to irrigate the crops, water is transported from lakes, wells, and canals in conventional methods.
The conventional methods are labor-intensive but are affordable.
These methods are ineffective and inefficient.
These methods result normally in uneven distribution of water. So few crops may get more water and few crops may get less water.
Waterlogging can occur in uneven land.
It employs the use of cattle and human labour in most cases.

Modern irrigation methods

Modern methods of irrigation take less time as compared to traditional methods. These methods need less manual work, and therefore, they are expensive. Modern irrigation methods are used to improve crop yields and to tackle the water scarcity issues. There are commonly two types of modern irrigation methods as follows:

Sprinkler irrigation method
Drip irrigation method

Sprinkler irrigation method

Nowadays, sprinkler irrigation is considered an easy and simple method of irrigation. Pipes are used to spray water onto the fields in the form of rain in this method. The sprinkler system prevents any water loss. This system does not create water logging issues. Additionally, groundwater equilibrium is also preserved. This method is done in those areas that have less quantity of water and uneven ground level.

The main pipeline is installed in the field and the perpendicular pipelines are attached. This will cover the entire agricultural field. These pipelines will have rotating nozzles at destined points. These tubes are designed to allow the pressurised water from the tube wells to flow through; this water then escapes from the rotating nozzles and sprinkles the crops. The method of sprinkler irrigation is required in areas where there are frequent changes in the temperature and humidity. The physical attributes and soil composition are enhanced by the constant sprinkle of water.

Fig: Sprinkler irrigation method

Advantages of sprinkler irrigation method

The common advantages of sprinkler irrigation methods are listed below:

It promotes soil preservation.
The soil productivity is raised.
It shields the crops from extreme cold or hot weather.
The sprinkler irrigation method can also be used to apply fertilisers and pesticides.
The soil is kept in its original physical and chemical state here.
This method is beneficial for sandy soil and uneven land.

Drip irrigation method

The method of drip irrigation is very common in areas with scarcity of water. On the agricultural field, pipelines connected with narrow tubes are installed. These narrow tubes have very tiny holes. Water drips at the plant roots when it passes through pipes and tubes through these tiny holes. The roots of the plants absorb water and transport that to the plant body through the vascular system. The main advantage of this method is that there is no wastage of water. Drip irrigation is also known as micro irrigation.

Fig: Drip irrigation method

Advantages of drip irrigation method

The common advantages of drip irrigation method are enlisted below:

Through this system, the roots of the plants directly receive the water.
It conserves a significant amount of water, which may be used to irrigate more land.
The lack of water spreading throughout the field prevents weeds from growing because it only contacts the plants directly.
It enhances the yield of crops.
Bacterial growth is restricted since the area close to the plants is dry.
It lessens the amount of water required for agriculture.

Significance of irrigation

The significance of irrigation are listed below:

Inconsistent and too little rainfall has a negative impact on agriculture. Droughts and famine are caused by insufficient precipitation. In regions with little rainfall, agricultural productivity is increased with the use of irrigation.
An irrigated field produces a lot more yield than an unirrigated field.
Mostly in our country, the climate and seasons are the two factors that affect the possibility of cultivation of crops in an area. Due to irrigation, farmers can grow more than one crop even in non-rainy seasons.
Most of the barren land has been cultivated due to these irrigation methods.
The different types of irrigation enhance the output and yield of crops.
The irrigation methods improve crop stability that ultimately provides financial stability to the farmers.

Practice Problems

Identify the method of irrigation that is used to conserve water?

Strip irrigation method
Sprinkler irrigation method
Drip irrigation method
Furrow irrigation method

Solution: Unlike the conventional overhead spray approach, the drip irrigation method delivers water to the plant's roots directly. Drip irrigation method saves up to 80% more water than the traditional method by reducing the amount of evaporation. The method of drip irrigation is very common in areas with scarcity of water. On the agricultural field, pipelines connected with narrow tubes are installed. These narrow tubes have very tiny holes. Water drips at the plant roots when it passes through pipes and tubes through these tiny holes. The roots of the plants absorb water and transport that to the plant body through the vascular system. Drip irrigation method is also known as micro irrigation method. Hence, the correct option is c.

2. Which method is a type of overhead irrigation?

Surface irrigation method
Center pivot irrigation method
Manual irrigation method
Drip irrigation method

Solution: Center pivot irrigation method is a type of overhead irrigation method. Through this type of irrigation system, water is distributed by a set of sprinklers. These sprinklers move on wheeled towers in a circular pattern. Hence, the correct option is b.

3. The ‘feeding bottle technique’ is classified under which irrigation method?

Drip irrigation method
Sprinkler irrigation method
Furrow irrigation method
All of the above

Solution: The method of drip irrigation is very common in areas with scarcity of water. On the agricultural field, pipelines connected with narrow tubes are installed. These narrow tubes have very tiny holes. Water drips at the plant roots when it passes through pipes and tubes through these tiny holes in this method. The roots of the plants then absorb water and transport that to the plant body through the vascular system. In the feeding bottle technique, bottles are inserted in the ground with holes at the bottom. Then the water is filled through the neck and this water drips out from the holes at bottom. This method also applies water directly in the root zone through tiny holes just like drip irrigation method. Hence this method is classified under the drip irrigation method. So, the correct option is a.

4. Which irrigation method is suitable for an area that has an irregular topography with excessive slope?

Sprinkler irrigation method
Sub-surface irrigation method
Furrow irrigation method
Strip irrigation method

Solution: Sprinkler irrigation method is used in those areas that have less quantity of water and uneven ground level. The main pipeline is installed first in the field and the perpendicular pipelines are attached to this. This will cover the entire agricultural field. These pipelines will have rotating nozzles at destined points. These tubes are designed to allow the pressurised water from the tube wells to flow through; this water then escapes from the rotating nozzles and sprinkles the crops. The method of sprinkler irrigation is required in areas where there are frequent changes in the temperature and humidity. The physical attributes and soil composition are enhanced by the constant sprinkle of water. Hence, the correct option is a.

FAQs

What is the most suitable pH range of water for irrigation?

Answer: The water used for irrigation should be in a range of pH 5.0 to 7.0.

What is the optimum water pressure used in drip irrigation method?

Answer: The optimum water pressure required for drip irrigation method is about 25 pounds per square inch.

What is the limitation of the drip irrigation method?

Answer: The main limitation of drip irrigation is that it requires high initial investments. Therefore, it is not affordable to all the farmers.

How efficient is the method of drip irrigation?

Answer: The method of drip irrigation is 90% efficient because the water is directly distributed to the roots of the plants. It allows the plants to efficiently use the supplied water.

Youtube link - Need to be created