Index
Three basic needs of agricultural production are seed, soil and water.In addition, insecticides, fertilizers, sun, an appropriate air temperature and human labor are needed. Of all these, water seems to be the most important requirement for agricultural production.
In many parts of the world, the available moisture in the root zone soil, either from rain or groundwater, may not be sufficient for the needs of plant life.
The shortage can occur during the entire season or only during part of it.
For proper plant/plant growth, water in the root zone soil is maintained by irrigation.
What is irrigation?
Irrigation can be defined as the science of applying water artificially to the soil according to the crop's water needs throughout the growing season for complete nutrition of the crop.
1.1. irrigation needs
Precipitation varies greatly in location, time, and amount. Rain intensity is very high during the monsoon season and lower during the other seasons.
Therefore, crops cannot be grown effectively on all areas without artificially irrigating the fields.
The need for irrigation is as follows:
a. Erratic rainfall throughout the year.
B. Less rain than necessary
C. Increased demand for food
i.e. Controlled water supply
1.2. Benefits of Irrigation
Every irrigation project is based on an economic vision. Therefore, any irrigation project must be economically viable.
As a rule, a project is implemented that earns at least 8% interest on the capital investment.
Unproductive projects are also sometimes carried out for public reasons.
The advantages of irrigation are the following:
a. Increased food production.
B. Electricity generation from hydropower.
C. Elimination of mixed cultures.
i.e. flood protection.
Y. Drought Insurance.
Gram. Resettlement of the forest.
h Simple communication.
I. prosperity of the nation.
j. Great Benefits.
k. domestic water supply.
I. Life quality.
m. employment.
1.3. irrigation disadvantages
The disadvantages of irrigation are the following:
a. Creation of a humid climate.
B. Formation of flood plains.
C. Requirement for accessible structures.
i.e. Creating a humid climate, swampy land, and breeding grounds for mosquitoes that cause outbreaks of diseases such as malaria and dengue fever.
Y. Water pollution problem: The leaching of nitrate applied to soil as fertilizer can contaminate groundwater.
F. Rise in the water table.
grams. Loss of soil fertility.
h Soil erosion.
I. loss of valuable land.
1.4. water source for irrigation
As we know, not all water is suitable for humans, just as not all water is suitable for plants.
Water that contains phytosanitary impurities is not suitable for irrigation.
The choice of water sources for irrigation depends on the following factors:
a. quantity requirements
B. Quality Factors
C. Location
i.e. Conflict and competition for water
a. Needed:
The source selected for irrigation must have a sufficient volume of water to meet the water needs of the command area.
If water is not available in sufficient quantities, the desired crop yields will not be achieved and conflicts between farmers will arise.
B. Quality Factors:
The concentration and composition of the ingredients dissolved in the water determine the quality of the irrigation use.
The various contaminants that make water unsuitable for irrigation are as follows:
I. Concentration of sediments in water.
ii. Total concentration of soluble salts
iii. Potentially toxic elements
4. Bacterial contamination
I. Concentration of sediments in water.
The effect of the sediments present in the irrigation water depends on the type of land being irrigated.
When water sediments are deposited on sandy soils, fertility is improved, but when the sediment comes from eroded areas, it can reduce fertility or reduce soil permeability.
Settled water causes problems in irrigation canals, causing canal fouling and increasing maintenance costs.
Therefore, from the perspective of sediment concentration, the groundwater and surface waters of reservoirs do not have enough sediment to cause serious problems in irrigation.
ii. Total concentration of soluble salts
The calcium, magnesium, sodium and potassium salts contained in irrigation water can be harmful to plants.
When present in excessive amounts, these salts reduce the osmotic activities of plants and can damage plant growth.
At the initial stage of irrigation there may not be any obvious harm, but over time the salt concentration in the soil will reach harmful levels.
iii. Potentially toxic elements
Various elements like boron, selenium etc. can be toxic to plant health.
Traces of boron are essential for plant growth, but concentrations above 0.3 ppm are considered toxic.
The presence of selenium, even in low concentrations, is toxic and should be avoided.
Boron is commonly present in many soaps. Therefore, soapy water must be used very carefully when watering.
C. Location of Sources:
The source of the irrigation canal should be located as close as possible to the command area. The closer to the source, the lower the losses, construction costs and maintenance costs.
d. conflict:
The selected water source must be free from conflict or dispute, or the dispute must be managed.
1.5. irrigation methods
Water can be applied to land for irrigation by a variety of methods. The choice of water application method depends on several factors. They are
I. country topography
ii. types of culture
iii. Solo-Typ
4. Amount and quality of available water
v. Farmer's ability to pay for the installation
He saw. cultural practices
vii. water requirements of the culture
VIII. Effective net precipitation at this location
ix. Initial development costs and availability of funds,
X. Farmer's preferences and experience.
There are many irrigation methods. They are
a. surface irrigation
B. underground irrigation
C. Air or sprinkler irrigation
i.e. buried irrigation
Y. Irrigation of the infiltration line
F. Suction Line Irrigation
1.5.1. underground irrigation
With underground irrigation, water is applied below the surface. This means that the water does not wet the soil surface. Groundwater nourishes the roots of plants through capillarity. The artificial water table is created and maintained at a specified depth, typically 30 to 75 cm below the surface of the earth.
Underground irrigation can be divided into the following two categories. They are:
1.5.1.1. Natural underground irrigation
In this type of irrigation, water comes underground from natural water sources such as streams, lakes, ponds, etc. Natural sub-irrigation is the natural irrigation of the soil without additional effort.
1.5.1.2. artificial underground irrigation
In this process, water is supplied to crops by capillarity through a network of underground perforated pipes that carry pressurized water that seeps through the perforations.
The depth of the tube should not be less than 40 cm so that the culture is not disturbed.
Pros and cons of underground irrigation
| Earnings | Mistake |
| 1. Reduction of evaporation and seepage losses. | 1. The acquisition costs are higher. |
| 2. No water wastage. | 2. The quality of the water must be good. |
| 3. No land wasting. | 3. Difficult to monitor. |
| 4. Reduction of soil erosion. | 4. Highly skilled technology and manpower are required. |
| 5. Minimum water requirement for cultivation. | 5. Possibility of pipe blockage. |
Adequacy of underground irrigation
~ Soil of uniform texture and permeability (sand, clay).
~ Country with uniform topography and moderate slope.
~ Good quality irrigation water.
Appropriate drainage arrangements will be made to drain excess water and prevent flooding of the field.
1.5.2. surface irrigation
It is the most common type of irrigation, applying water directly to the surface of the field. It is also called iceberg irrigation. The efficiency of surface irrigation depends on proper soil preparation and distribution system.
Types of surface irrigation
1.5.2.1. After the irrigation system water supply
According to the irrigation system, surface irrigation is classified as follows:
a. flow irrigation
When the irrigation water available at a higher level is fed to the lower level by the action of gravity, this type of irrigation is called flow irrigation.
B. turn on the irrigation
If the irrigation water is raised mechanically or manually, this is referred to as lift irrigation.
1.5.2.2. According to the irrigation water distribution method
According to the irrigation water distribution method, surface irrigation is classified as:
a. flood method
b. contour farming
C. Groove Methods
1. Flooding Methods
With this type of surface, the irrigated soil is kept submerged and completely inundated with water. It can be classified as:
a. Wild/uncontrolled flooding
It is one of the most primitive and inadequate irrigation methods. Water spreads or floods the field without much control or prior preparation.
physical fitness
~ This method is suitable for flood irrigation system, pasture and forage crops, which is economical.
Disadvantages
~ Inefficient use of water
~ Uneven water distribution
~ overhydration
~ Large seepage loss
B. controlled flooding
In this type of flood, water is applied to the ground in a controlled manner. There is adequate control of both flow and amount of water.
Types of controlled floods
Controlled floods are classified into the following types:
I. free tide
ii. border flooding
iii. Check flood
4. Beckenhochwasser
v. Konturseiten
He saw. zigzag method
I. free tide
The free-flood method is also called plot irrigation. The field is divided into several plots at the upper end.
The size of the plot depends on the porosity of the soil.
physical fitness
~ In the area with sufficient amount of cheap water.
~ Relatively flat field.
Services
~ The initial cost of preparing the land is less.
Disadvantages
~ Work demands are high.
~ Low water application efficiency.
ii. Border strip or border flood procedures
The agricultural estate is divided into a series of tracks. The strips are about 10-20 m wide and 100-400 m long.
Water flows from the utility ditch to the rail Water flows from the top of the ditch to the bottom of the ditch.
physical fitness
~ Suitable for all closed-growing cultures.
~ Suitable for row crops and orchards.
Services
~ Requires less labor and time.
~ Low maintenance costs.
~ Uses a large amount of water from the creek to safely irrigate the field.
Disadvantages
~ High acquisition costs.
~ Requires proper leveling.
~ Requires a lot of water.
iii. Check flood
Control tides are similar to regular tides or free tides, except that the water is controlled by surrounding the control area with low, flat levees.
If the land has an initial slope, dikes can follow the contour. It is suitable for watering food and crops on heavy soils.
physical fitness
~ This method is suitable for permeable and impermeable soils.
~ With permeable soil, water can spread well without seepage losses.
~ If the soil is impermeable, water can be retained for a long time.
Services
~ High irrigation efficiency can be achieved.
~ Unskilled labor may be employed.
Disadvantages
~ A lot of work is required.
~ Dikes limit the use of modern machinery.
4. Basin flooding
It is a special type of backwater. This irrigation method is used to irrigate orchards and large trees.
Generally, one or more trees are placed in the basin and the surface is flooded depending on the control method.
physical fitness
~ It is suitable for orchards and trees.
Services
~ Less work.
~ Lower maintenance costs.
~ Ensure efficient use of water.
Disadvantages
~ High acquisition costs.
~ Large amount of water required.
~ Leveling required.
v. Konturseiten
This method is better suited for steeper terrain. The pitch is traversed by a relatively dense network of contoured full-backs.
The lateral clearance depends on the terrain, the flatness of the slope and the type of soil.
physical fitness
~ For closed crops on sloping terrain.
Services
~ It can be used on all types of floors.
~ Low cost.
Disadvantages
~ Inefficient use of water.
~ Unequal distribution of land.
~ About watering.
~ Large seepage.
He saw. zigzag method
The zigzag method is a special method of controlled flooding in which the water applied to the land takes a tortuous path that begins at the field channel and reaches the cul-de-sac of each plot.
To do this, the entire property is divided into several square (or rectangular) plots. Each plot is provided with dams (or small dikes) so that the water follows the tortuous path that runs through the entire plot.
The zigzag method works well for relatively flat plots. However, the method is not suitable when agricultural work is carried out with modern agricultural machinery.
2. Contour farming
It is used in mountainous areas with steep slopes and rapidly sloping contours.
The land is divided into a series of strips in longitudinal curves, and the cultivation of the crop is carried out along the contours instead of the usual descent.
Contour processing reduces runoff and soil loss. This method is suitable in mountain regions with steep slopes.
3. Furrow Irrigation
This is an excellent irrigation method for row crops such as potatoes, cauliflower, etc.
Furrows are a series of long, narrow channels built into the field. The grooves vary in depth from 8 to 30 cm and can reach 400 meters in length.
Rows that are too long result in excessive seepage at the top and insufficient water at the bottom. Deep furrows are often used for row crops.
Small flat grooves, so-called ripples, are particularly suitable for meadows and small grains. Plants are usually planted on or near furrows or furrows.
Water applied in the field penetrates the soil and spreads to the root zone.
The slots are of two types. They are:
a. straight grooves
B. Contour grooves
Services
~ The water efficiency is high
Puddles on heavy soils are also reduced and it is possible to start processing immediately after watering with changing supply conditions, the number of furrows supplied at the same time can be easily changed. In this way, a very high irrigation efficiency can be achieved.
~ Inexpensive to build and maintain.
~ Evaporation loss is low.
~ The grooves also serve as drainage.
~ Less waste of soil when furrowing.
~ Only one-fifth to half of the earth is covered with water.
~ Allows for earlier harvest after watering.
~ Less loss.
Disadvantages
The disadvantages of furrow irrigation are:
~ Requires the ability to make grooves.
~ The mud in the furrows must be removed regularly.
~ Possibility of increased salinity between the furrows.
~ Water loss at the downstream end if dikes are not used at the ends.
~ The need for additional plowing work, ie furrow construction.
~ Potential for further erosion
~ Furrow irrigation is more labor intensive than any other surface irrigation method.
physical fitness
Furrow irrigation is suitable under the following conditions:
~ Not relatively flat terrain.
~ On level ground the furrows are straight, but on sloping ground the furrows are built up on the contour.
Also read:Full details of furrow irrigation
1.5.3. drip irrigation
It is a special type of underground irrigation. It is also called drip irrigation.
It is the latest irrigation technique in fields where irrigation is scarce due to salt problems.
With this method, water is applied slowly and directly to the root zones of the plants.
resources
~ The main tank maintains the pressure.
~ Main and secondary pipe: black PVC.
~ Lateral Lines: 10-20mm diameter.
~ The output through the nozzle is 2 to 10 litres/h.
physical fitness
~ This method is suitable for any topography.
Services:
~ Less irrigation water.
~ Avoid flooding.
~ Less water loss.
~ High crop yield.
~ Reduction of labor costs.
~ No excessive watering.
Disadvantages
~ The initial cost is high.
~ Nozzle clogging problem.
Also read: Full detail of drip irrigation
1.5.4. buried irrigation
It's a replacement of channels for channels.
In this system, the water is conducted through a channel from the water supply source to the irrigation area and the indoor area. It is distributed by the pressure of gravity.
The distribution pipe receives water from the yard pipe or from the open channel along the contour lines.
The water flows to field pipes, which in turn flow into flexible irrigation pipes.
The water rises mechanically to the underground networks when the level of the supply source is below the irrigated surface.
1.5.5. Irrigation of the infiltration line
A relatively new irrigation concept is seepage line irrigation, which can provide limited but guaranteed easy watering of plants during the critical period.
Well numbers may be developed at a different point in and around the area where heavy water seepage is observed. These wells are connected by pipes to a central point in the command area, dug like a water tank. Water is provided to the person from this tank for a small fee.
1.5.6. sprinkler irrigation
Such irrigation is also called sprinkler irrigation.
With this irrigation method, water is applied in the form of sprinklers or artificial rain.
With the overhead irrigation method, water is sprayed into the air and allowed to fall to the soil surface like rain.
The spray is developed by the flow of pressurized water through small holes or nozzles.
Pipe pressure is usually achieved by pumping.
With careful selection of nozzle sizes, operating pressure, and sprinkler spacing, the amount of irrigation water needed to replenish the crop's root zone can be applied almost uniformly at the rate appropriate for the crop.
Preferred Circumstances
Favorable conditions for sprinkler irrigation.
The following conditions are favorable for sprinkler irrigation.
~ If the terrain is hilly, sprinkler irrigation can be used as it is costly to level the terrain to the surface.
~ If the soil is very permeable, sprinkler irrigation can be used as it is difficult to achieve good water distribution with surface irrigation.
~ If the depth of the ground is shallow, you can use the sprinkler because it would be difficult to properly level the ground for shallow pouring.
~ Sprinkler irrigation can also be used on steep terrain or in easily eroded soils where surface irrigation is not possible.
~ Overhead irrigation can be used when the irrigation flow is too low to distribute the water efficiently by surface irrigation.
~ Sprinkler irrigation can be used when the land needs to be used in a short time.
~ It is suitable when the soil requires a light water application at regular intervals.
~ It is suitable for regions with high water table where surface irrigation leaching losses are high.
~ It is suitable for shallow root crops.
~ It is suitable for effective fertilization and soil improvement,
~ It is suitable when reliable and well-trained workers are not available for surface irrigation.
Services
~ It is not necessary to prepare the land.
~ The water efficiency is very high, about 80%.
~ More land can be irrigated with less water.
~ Protects the soil and plants from extreme weather conditions such as frost.
~ Even application of water.
~ Prevention of soil erosion.
~ Application offertilizerIt can be done along with irrigation water.
~ Elimination of transport routes, therefore without transport loss.
~ Suitable for all soil types except heavy clay.
~ Indicated for irrigation of crops where the plant population per unit area is very high.
~ It is more suitable for oilseeds and other grain and vegetable crops.
~ Water saving.
~ Tighter water application control, suitable for light, frequent watering and increased water application efficiency.
~ Higher performance.
~ System mobility.
~ It can also be used for curly areas.
~ Save the earth like no othernightclubsare needed etc.
~ Affects a more conductive microclimate.
~ Areas higher than the source can be watered.
~ Possibility of using soluble and chemical fertilizers.
~ Reduced problems with sprinkler nozzles clogging with sediment-laden water.
Disadvantages
~ The initial cost is high.
~ Applying pressure.
~ Not suitable for crops that require a lot of water depth.
~ Electricity is required to operate the pump.
~ wind effect.
~ Nozzle clogging problem.
~ Good quality when water is needed.
~ Requires frequent monitoring.
~ Requires a continuous water supply.
~ Not suitable for heavy floors.
~ Evaporative losses are high in a place with high temperature and high wind speed.
Classification of sprinkler systems
I. Permanent system: It is a system where both the net and the sides are fixed.
ii. Semi-permanent system: the nets are permanently attached and the sides are wearable.
iii. Portable system: The system where the mesh and side panels are portable.
Sprinkler Irrigation System Components
The sprinkler system generally consists of the following components:
~ A pump unit
~ Networks/subnets and laterals.
~ Connects
~ sprinkler head
~ Other accessories such as valves, elbows, plugs and bolts.
Also read: irrigation duty