Irrigation: Meaning, Importance and Types.

 Meaning of Irrigation

Watering of crops is necessary for the growth and development of plants. During the period of water shortage or drought, farmers must apply water to plants to prevent die-back or wilting.

This process of applying water to crops to avoid dieback is called irrigation.  Irrigation refers to the artificial application of water to the soil to soften the tillage pan, aid plant growth, and enhance development.

Farmers Irrigate farms to supply the moisture requires for plant growth and productivity. Food crops require a constant water supply to ensure sufficient water availability to supplement natural sources for plants to thrive and survive.

Similarly, Irrigation can be defined as the artificial application of water to crops to supply moisture required for plant growth, protect against drought, and aid all-year-round cultivation.

Nursery crops such as oil palm, rubber, cocoa, oranges, mangoes,(tree crops)  tomatoes, pepper, garden eggs, and other ornamental plants pepper, garden egg, and other ornamental plants require constant irrigation or watering during nursery stage to ensure survival and growth before transplanting to the main field.

Food production during rainfed agriculture is often inadequate to meet global population demand. Therefore, the application of water to crops is necessary to boost food production and enhance the attainment of food sufficiency.  

During during water supply, it is paramount to know that the water requirement of crops varies depending on the type of crop and the environmental condition. For example, the water requirement for crops cultivated in screen houses, pots, and trays varies significantly from crops cultivated directly into the soil.  

The significance of irrigation in crop-sustaining during drought or dry season cannot be overemphasized, and ensuring that crops receive enough quantity of water during periods of water shortage is paramount for plant survival and productivity.

Aim/ Purpose of Irrigation

The following is the purpose of irrigating agricultural land  

1. To supply water to the soil essentially for plant growth and development
2. To protect crops against drought.
3. To cool the soil and the environment necessary for plant growth.
4. To wash away or reduce the salt content of the soil
5. To soften soil tillage pan and clods
6. To provide a conducive environment for the survival of microorganisms
7. To aid the application of fertilizer.

Importance of Irrigation in Agriculture

1. It Aids Early Planting: water application to crops makes early planting possible in agriculture, protects crops against crop failure, and enables farmers to embark on crop cultivation at any time irrespective of the prevailing climatic condition. 
2. Supply Water Necessary for Plant Growth: Water has a high influence on plant growth and productivity. No plant can survive extremely high temperatures for a long period. Therefore, Irrigation supplies moisture to the soil which helps to promote healthy plant growth and development.
3. Soften tillage Pan or Cloud: the application of water to the soil before tillage helps to soften the soil for easy tillage operation. Tilling dried soil is usually challenging often resulting in dust or clumpy. application of water before tillage helps the farmer to achieve fine tilt and improve soil preparedness to receive seed.
4. Aid the Survival of Crops during Draught:  many crops cannot survive prolonged drought. Draught refers to the absence of rain (i.e., a period where there is supposed to be rain, but there is no rain). draught can last more than necessary leading to the death of economic crops. However, water supply helps to sustain crops and minimize the adverse effects of rain shortage.
5. Less Reliance on Rain: irrigation makes farmers less dependent on rain. The impacts of climatic change cause variations in amount the of rainfall which influences planting date.  Many farmers during the onset of the farming season depend on rain for cultivation which delays planting or often leads to late planting. Irrigation helps farmers to start cultivation at any time and reduce dependence on rainfed farming.  
6. Lower Soil Temperature: dry soil tends to be very hard and contains high temperatures which can be unconducive for crop Cultivation. On the other hand, wet soil contains low temperatures which helps increase crop growth. However, irrigation helps lower soil temperature and create favorable conditions for crop growth.
7. Aid Continuous Crop Production: The application of water crops makes farmers less dependent on rain and ensures continuous crop cultivation. In Irrigation farming, farmers are less dependent on rainfed and are not restricted by seasonal rainfall patterns.  This enables farmers to ensure continuous crop cultivation, increase yield, and promote all-year-round crop production.
8. Modify Soil and Plant Environment: irrigation cools the soil and makes the plant leaves succulent, greener, and healthier. Inadequate water will make the environment dry, and plants will continue to suffer while adequate water lowers soil temperature, enhances nutrient absorption, and creates a conducive environment for plant growth.
9. Enhances Microbial Decomposition: since irrigation helps to modify the environment, and create room for micro and macro organisms to thrive. These living organisms help decompose plants and animal materials and incorporate them into the soil. This process helps to improve the soil structure, as well as increase soil fertility.
10. Dissolve Nutrients for Root Absorption: This is another important aspect of irrigation agriculture.  Irrigation helps circulate essential nutrients around the soil which makes them readily available for plant roots to absorb. This increases nutrient uptake and promotes the overall growth and productivity of crops
11. Aid the Application of Liquid Fertilizer (fertigation):  irrigation can serve as a channel for the application of liquid fertilizer directly to crops. Fertilizers can be dissolved in water and applied directly during irrigation. This process of dissolving liquid fertilizer and apply through irrigation is known as fertigation. Fertigation ensures the even distribution of fertilizer and improves fertilizer application efficiency.

Source of Water for Irrigation

The following are the sources of water for irrigation

1. Rivers
2. Lakes
3. Streams
4. Ponds
5. Bore-hole
6. Wells
7. Reservoirs
8. Springs
9. Brooks
10. Dams

1. Rivers: a natural body of water flowing toward the seas. The flow of the river naturally influences seasonal variation which can pose serious challenges for irrigation.   It is one of the important sources of irrigation water use in agriculture. Water from streams can be directed to the farmland through constructed channels, farmers may use.  Buckets, bows, and watering can also be used to fetch water manually for irrigating crops, additionally, pipes are laid to the river while a centrifuge pump is used to draw water from the river into reservoirs or storage tanks for watering crops.

1. Lake:  a lake is a large body of water surrounded by land. It’s a vital source of water for irrigating agricultural land. To source water for Lake Bucket, a bow or watering can be used to fetch water to irrigate the soil. A pipe can also laid to the lake, and a centrifuge pump is used to draw water from the lake into reservoirs or storage tanks for watering crops.
2. Stream: This is a continuous flow of surface water within a narrow channel. The water level in the Stream usually fluctuates during the season i.e. dry up in the dry season and fills during rain.  This posed serious challenges to the amount of water available for irrigating agricultural land. To source water, a watering channel is constructed to direct water to the farm. A bucket, bow, or watering can is used to fetch water from the river while a pipe and pump can used to draw water from the river into reservoirs or storage tanks for irrigation purposes.
3. Pond:  this is a small body reservoir of water artificially constructed in or within the stream bank.  Ponds are shallow and may not contain sufficient water for large-scale farming.  To source water from the pond, a bucket or watering can may be used to fetch water or a surface pump can also be used to transport water for irrigation.
4. Borehole: A borehole is a modern and reliable source of irrigation for both subsistence and commercial agriculture. It involves drilling a narrow shaft into the ground to obtain water. The water from the borehole is channeled through a pipe to a reservoir or tank, where it can be used to irrigate crops directly. It is considered one of the most dependable sources of water for irrigation.
5. Wells:  A well is a man-made narrow hole dug into the ground to access underground water. A common area where unground water is abundant or where there are large bodies of water. In a well with enough quantity of water, the farmers may use a surface pump to draw water from the well to water crops. Water source from the well can be stored in a tank or reservoir for further uses.
6. Springs Water: This type of water usually flows from a soil aquifer to the surface of the Earth for irrigating farmland. Spring water is possible in areas where there is enough quantity of underground water and stored in a tank or reservoir for irrigation purposes.
7. Dams are the oldest and most reliable water source for irrigation. Dam are usually constructed to restrict the flow of surface water and create reservoir water storage the source water from the dam Pipe is laid from the dam to the farm to ensure a steady source of water supply.
8. Brooks:  this is a natural, temporary, and small running body of water that serves as a tributary to other rivers. It is usually used as a source of irrigating crops. It is used for irrigation because they can hardly dry which makes it one of the most dependable sources of water for irrigation.
9. Reservoirs: this body of water is created to purposely restrict or store water. It is a large natural or artificial lake created to serve as a water supply. Reservoirs can be established on the farm to store water for consistent water supply for irrigation purposes.

Advantages and Disadvantages of Irrigation

The advantages and disadvantages of Irrigation are enumerated below:

s/no	Advantage	Disadvantage
1	It makes planting easily possible	The high cost of irrigation equipment discourages farmers from practicing irrigation.
2	It helps to add water to the soil/supply moisture to the soil for plant growth	It leads to increased soil salinity
3	It helps to soften the soil for easy tillage operations	It leads to the spread of disease
4	It helps to enhance  the survival of crops during draught	It increases the  buildup and spread of pests
5	It makes farmers less reliance  on rainfed farming	It leads to the building of Vectors such as. snail, tsetse fly, mosquitoes on the farm
6	It helps to lower soil temperature	It increases the  buildup and spread of pests
7	It aids all year-round production	It may lead to leaching( downward washing of soil nutrients)
8	It improves the soil and plant environment	It may lead to  soil erosion /flooding
9	It helps to enhance the microbial decomposition of organic matter	It encourages the growth of weed
10	It improves the soil and plant environment	Inadequate water supply for irrigation in certain areas and periods

Irrigation System

 

An irrigation system refers to a collection of tools or facilitates design to covey water from its source of supply into the agricultural field for irrigation purposes. Similarly, it refers to the various ways of directing, conveying, and applying water to crops on the field. It consists of various components such as the pumping system, conveyance facilities, a distribution network, and field application equipment required to irrigate agricultural land effectively.

The type of watering system used in agriculture varies significantly, depending on the types of farming, source of water, soil types, and topography. The irrigation system works by drawing water directly from the source of supply and transporting it through the conveyance system into the storage facilities or distributive facilities for use on the farm.  

Types of Irrigation of Systems in Agriculture

The types of irrigation practices in agricultural production include  

1. Surface
2. Overhead and
3. Sub-surface

Continue no, Types of Irrigation, Meaning, Advantages and Disadvantage

Factors to Consider Before Choosing Irrigation Systems

1. Soil types
2. Topography,
3. Nature of water supply,
4. Size of farmland
5. Types of crop-grown

1. Soil types: the soil types are another factor to be considered before choosing the type of irrigation facilities. Soil types such as clay, sandy, and loamy soil have their physical properties. Such as the ability to retain water,  clay soil has a high ability to retain water, sandy soil is so porous and does not retain water while loamy soil retains a moderate amount of water. This affects the rate of water used by crops. More so, sandy soil can easily heat up and hence require frequent irrigation, clay soil is very cool and does not require frequent watering, while loamy soil retains moderate temperature. Sandy soil has high losses which may cause erodible soil and leaching of important soil minerals.
2. Topography: The nature of the soil has a serious influence on the types of irrigation systems to adopt. The topography of the farmland can either be flat, sloppy, or undulating.  Sloppy and undulating topography will require an overhead irrigation system, while flat topography will require a surface or drip irrigation system. The undulating terrain and sloppy topography need to be monitored to reduce erodibility.
3. Nature of Water Supply: the sources of water supply such as wells, springs, bore whole, brooks, dams, rivers, and lakes have determined the types of irrigation systems to be adopted. Boreholes, Dams, rivers, and lakes have high volumes of water that are hardly dry which makes them a good choice for commercial farming and it is not labor-intensive.  Well, brook, and stream easily influence whether they are they are subject to variation
4. Size of Farm Land: small farms require small irrigation facilities while commercial farms require sophisticated types of irrigation.  A small farm may require surface irrigation while commercial farm require a sprinkler irrigation system
5. Types of Crop Grown: This is another factor to be considered before choosing the irrigation system to be adopted.  Vegetable and nursery crops may need sprinkler irrigation while yam, maize, and wheat require overhead or drip irrigation systems. Maize, wheat, and yam may obstruct movement on the farm hence overhead system is adopted.
6. Water Quality: water with high salt content will increase the salinity of the soil which causes a reaction in the soil leading to the death of economic crops.