What are the components of drip irrigation? What are the factors to be considered while designing a drip irrigation system?

WHAT IS DRIP IRRIGATION?

Drip irrigation is the type of irrigation in which water is applied directly to the root zone of the plants at frequent intervals and in precise quantity. This method conserves water and soil while reducing runoff and erosion. Drip irrigation is the most widely used method of delivering water to plants. It involves the use of small "pipes" that deliver water directly to distant locations on a large scale. Drippers are placed either above the soil surface or buried below the surface.

COMPONENTS OF A DRIP IRRIGATION SYSTEM

The main components of a drip irrigation system are:

Water Source

Drip irrigation can use water from a pond, irrigation canal, groundwater, or public water supply (such as county or city water) by simply attaching a garden hose to a normal faucet. High iron levels, which may be present in well systems, are unsuitable for drip irrigation systems because they clog emitters.

Pumping System

A pumping system is used to move the water from the source to the field. Power sources for pumping systems include electricity, diesel, gas, and even sunshine. Drip irrigation systems function at low pressure in comparison to sprinkler and center pivot irrigation systems, allowing even gravity to pressurize drip lines.

Distribution System

The distribution system carries the water from the source to the field head by connecting it to a mainline. Any tube, including PVC pipes, with a diameter large enough to provide the appropriate volume of water to the field, can be used as a distribution system.

Mainline Tubing

Mainline tubing is flexible tubing typically ½ inch in diameter. In a drip irrigation system, the mainline tubing usually enters the field at the head and is attached to drip tape, which enters the field at a 90-degree angle.

Submain line

Water is transported from the mainline to the dripline by the submain. Depending on the size and type of the plot, there may be several Submains from a single Mainline.

Drip Tape or Drip Tube

The drip tape or drip tube connects to the mainline tubing. Slits are integrated into the tube of drip tape which allows water to drop out. Wherever a drip point is desired, emitters must be put into a drip tube.

Pressure Regulator

Drip irrigation is a low-pressure system but most pumps or water systems deliver well the water pressure required by the drip line. Pressure regulators monitor the pressure rate in order to keep drip lines from blowing out and leaking while they are in use.

Filtration system

The dirt, sediment, and filth that would clog drip tape lines, micro-sprinklers, and emitters are removed using filters and screens. Filters are essential if the water is coming from a stream, irrigation canal, or pond.

Emitters

Emitters are inserted into the drip tube. Emitters are classified into two.

Non-pressure-compensated drippers' flow is proportional to pressure; as a result, it is higher at the beginning of the line than it is at the end. With very long stretches of driplines, the difference can be significant.

Pressure-compensated drippers generate a constant flow from the first dripper to the last. This uniformity provides an even irrigation rate regardless of the dripper’s position along the line, which in turn allows longer stretches of driplines.

FACTORS TO BE CONSIDERED FOR THE DESIGN OF A DRIP IRRIGATION SYSTEM

Topography survey of the land 

The slope of the ground and how level or irregular it is is referred to as topography. Topography survey of the land to be irrigated will help you determine where emitters should be placed and how they should be laid out. This will help determine things like slope, water flow, and drainage. In a topography survey, the measurement is done by tape, chain, or even by coordinates from google maps.

Agriculture or crop data

Crop data such as the type of crop, their size, and other factors such as soil conditions determine which types of drippers will best suit your needs and how much water they need to produce. The cost of investing in drip systems could be high. As a result, it is preferable to save their use for high-value crops like vegetables, small fruits, and orchard crops rather than using them on staple crops like wheat and soybeans.

Soil analysis

The main constituents of soil are sand, silt, and clay. Soil is further classified into 14 types. Soil analysis is the process of determining the chemical and physical characteristics of the soil. It is used to determine the suitability of soil for a particular use, such as growing crops or building on.

Water analysis

Water analysis gives us information about water's chemical, physical and biological properties. It is used to determine the suitability of the water for drip irrigation. Water Sources are bore, open well, rivers, canals, and water tanks. Filtration Systems are based on water quality. Filtration systems are classified into hydro cyclone filter, sand separator, sand filter, and screen & disc filter.

The climate of the place

Determine the climate of the place you are installing the system, rainfall, irrigation needed, frost period, etc., all this helps in deciding, pipe size and type, where and how deep to lay pipes, and how many emitters per plant are required

Power available

Drip irrigation systems can be powered by electricity from either an electric pump (which draws power from a wall outlet) or any other source such as solar panels on your roof or wind turbines in your backyard.

Flow rate

The water flow rate is undoubtedly one of the factors that must be taken into consideration when it comes to irrigation. Either liters per minute or cubic meters per hour are used to calculate the flow rate. The amount of water that an emitter can distribute while operating at a given pressure is known as the working flow rate.

HYDRAULIC FLOW THEORY OF DRIPPERS

The 3 types of flow through a dripper are laminar, turbulent, and vortex flow. Laminar flows are smooth and streamlined, whereas turbulent flows are irregular and chaotic (e.g., Zig-zag flow). Laminar flow does not require pressure compensation but the turbulent flow is chaotic and hence, requires pressure compensation. Vortex flow means the rotational or circular motion of a liquid.

After reading this article, you should be able to understand what is drip irrigation. You might also get an idea of the major components of a drip irrigation system and the factors to be considered while designing a drip irrigation system.