Various methods of irrigation in agriculture Irrigation is one of the oldest human activities whose main purpose is to increase the production of agricultural products. In irrigation, soil moisture should be maintained to the extent that the plant is not dehydrated. It should be noted that lack of soil moisture is as problematic for the plant as excessive soil moisture. Therefore, excessive watering should not be done, because it will cause the plant to be damaged by excessive moisture and reduce crop yield. In some cases, the purpose of irrigation can be to control air temperature, humidity and reduce plant pests and diseases.
Types of irrigation methods can be classified into two general categories: surface irrigation and pressure irrigation. The main difference between surface and pressurized irrigation methods is the type of force used to distribute water in the field. In surface irrigation, water is distributed on the ground by gravity or gravity. For this reason, surface irrigation is also called gravity irrigation. In pressurized irrigation, pumps and pipes are used to transfer water and sprinklers are used to distribute water on the farm surface. Sprayers are sprinklers or droppers that are placed on a tube called a side tube. The lateral tube is also called the lateral tube.
Types of irrigation methods:
Types of irrigation methods can be classified into two general categories: surface irrigation and pressure irrigation. The main difference between surface and pressurized irrigation methods is the type of force used to distribute water in the field. In surface irrigation, water is distributed on the ground by gravity or gravity. For this reason, surface irrigation is also called gravity irrigation. In pressurized irrigation, pumps and pipes are used to transfer water and sprinklers are used to distribute water on the field. Sprayers are sprinklers or droppers that are placed on a tube called a side tube. The lateral tube is also called the lateral tube.
Types of surface irrigation methods
Surface irrigation is the oldest and most widespread method of irrigation, also called traditional irrigation. The three main methods of surface irrigation include strip irrigation, furrow irrigation and furrow irrigation. Figure 1 shows the furrow irrigation method.
Advantages of surface irrigation:
- Simplicity and no need for complex devices and equipment
- Low initial investment cost
- No need for energy
Disadvantages of surface irrigation:
In cases where the slope of the land is high, this method of irrigation can not be used and the land must be leveled or sloped, which is very expensive.
- Surface irrigation is not suitable for light and sandy soils.
- Surface irrigation requires more labor than pressurized irrigation methods.
- The efficiency of surface irrigation is low, which causes water wastage.
- Surface irrigation requires high water flow.
Types of pressurized irrigation methods
Due to the novelty of this irrigation method, pressurized irrigation systems are also called modern irrigation systems. Pressure irrigation methods are divided into two general categories: sprinkler irrigation and drip irrigation..
Water comes out of the sprinklers in the form of raindrops and rains on the plant and agricultural land, and in the drip irrigation method, water comes out of the drippers in the form of drops or drips. Another difference between sprinkler and drip irrigation methods is in the wet area of the land. In rain irrigation, the whole field is irrigated, but in drip irrigation, only the area around the plant is irrigated. For this reason, drip irrigation is also called local irrigation.
Local irrigation in drip irrigation systems reduces water consumption and increases irrigation efficiency compared to sprinkler irrigation systems.
There is a difference between sprinkler irrigation and drip irrigation in terms of water pressure in the system. So that:
Sprinkler irrigation systems require more pressure than drip irrigation systems
The following are the main advantages of pressurized irrigation methods.
Advantages of pressurized irrigation:
- High efficiency in irrigationImproving the quality and quantity of agricultural products
- Uniformity of water distribution at ground level
- Ability to irrigate on uneven and sloping lands that can not be irrigated by surface irrigation.
- High automation capability
- Possibility of spreading fertilizer or poison at the same time as irrigation
- Less need for labor
- Possibility to use pressurized irrigation to control the air temperature in case of frost or heat
Types of sprinkler irrigation methods:
The main components of a sprinkler irrigation system include the pump, the main pipe, the side pipe and the sprinklers. Various classification methods have been proposed for sprinkler irrigation systems. In one of these methods, sprinkler irrigation systems are classified into two categories: classical (non-mechanized) and mechanized. Other classification methods include classification based on agricultural use and classification based on portability.
Classic sprinkler irrigation:
Classical sprinkler irrigation methods are methods in which sprinklers or side pipes are moved with the help of labor. Types of classical methods include fully mobile classic, semi-mobile classic, fixed classic with movable sprinklers, full fixed classic and spool hose classic.
Mechanized sprinkler irrigation methods:
In mechanized sprinkler irrigation methods, electricity or fuel energy is used to move the sprinklers and side pipes to make irrigation easier and less labor intensive. Mechanized sprinkler irrigation methods are suitable for large and integrated lands and the technology used in them is more complex than classical methods. Mechanized sprinkler irrigation methods include wheeled irrigation system (Willow), chariot irrigation system, linear mobile irrigation system (linear) and hand irrigation system (centerpit). Figure 3 shows the Central Pivot irrigation system.
Types of drip irrigation methods:
The various components of a drip irrigation system can include a pumping station, water treatment equipment, fertilizer and chemical injection tank, main pipe, side pipe, and drippers or emitters. Drip irrigation systems can be divided into the following four categories:
1- Drip irrigation
2- Spray irrigation
3- Bubbler irrigation
4- Subsurface irrigation
drop irrigation :
In this method, water with low flow intensity is applied in drops on the soil surface and moistens the soil around the plant.
Spray irrigation: In this method, water is sprayed on the soil and irrigates the environment around the tree.
In Baboller irrigation, water is applied as a bubble on the soil around the tree at low flow intensity.
Subsurface irrigation :
In this method, the water outlet is located below the soil surface. Side pipes for subsurface drip irrigation are located at a depth of about 10 to 60 cm and irrigation is done below the soil surface, which minimizes water evaporation, saving water consumption and weed control. It becomes. This system also reduces the humidity of the plant’s underlying environment, which is effective in reducing fungal diseases. In this irrigation method, it is better to have short irrigation intervals.
It is interesting to know that a method called pit irrigation has been used in the desert regions of Iran for a long time, which is in fact a traditional type of subsurface irrigation method. In jug irrigation, a permeable earthenware vessel is placed in the soil near the foot of a tree or plant, and water is poured into the jug manually and is gradually absorbed by the soil and the plant from the container wall. And the water needed for pottery or pots is supplied by water pipes, which has made this irrigation method easy to use.