Advantage and disadvantages of drip irrigation system
Drip irrigation system is a type of irrigation which involves delivering of water onto the soil at very low rates from small outlets fitted on to a drip tape also known as emitters. This is the major advantage of drip irrigation system.
The drip emitters that are commonly used are the drip tape/line, button drippers and arrow drippers.
The emitters ensure that water is directly delivered to the planted crops according to the farmer’s requirements or according to the manufacturer specifications.
The water drops slowly on the roots of the plants above the soil surface according to the placement of the mainline (pipe that carry the irrigation water).
Different emitters on a best irrigation system have different flow rates (amount of water it discharges per unit time)This is what guides an irrigation engineer on the size of mainline to use when doing a specific design
It (emitter) also dictates the time needed to irrigate a specific size of a farm
In drip irrigation system, we have a combination of equipment which are put together to make sure water is supplied to the plants so that only part of the soil is wetted unlike other types of irrigation systems which involves entire wetting of the soil parts.
The advantage of drip irrigation system is that it distributes water through a network of valves, pipes tubing’s and emitters which work in a well articulated scientific model to offer high efficiency in power.
The main advantage of drip irrigation system is to offer farmer with the best possible economical water use while also keeping pumping cost low in case one chooses drippers instead of tapes.
For the drip irrigation system that uses the drip tape/line there is no need of pumping unit since pressure needed is low, the system utilizes the gravity.
When the gravity is considered, the height of the water storage for irrigation must be raised high to develop pressure to push water through the type.
Benefit/ advantage of drip irrigation system
- Drip irrigation system is the most efficient method of irrigation since water through emitters is directly delivered to the plant root zone hence economical on water usage.
- In drip irrigation system there is constant benefit of water supply in small quantities to the plants thus creating ideal moist condition for proper growth of most plants.
- Drip irrigation system minimizes weed growth since water is only supplied to a particular crop root.
- Best drip irrigation system helps in control of fungal diseases which grow very fast under moist conditions.
- Timeliness and labor saving. In best drip irrigation system, the control valves can be managed by one personnel to operate the whole system thus minimizing the labor costs hence minimizing production cost.
- Ease in fertilizer application. In best drip irrigation system, method of liquid fertilizer application known as Fertigation is very easy and fast since water emitters are used to directly distribute fertilizers to particular crop/plants
- Cannot get disrupted by wind
- Recycled non-potable water can be safely used.
- Moisture within the root zone can be maintained at field capacity.
- Soil erosion is lessened. This is because water is not flooded in the farm.
- Water distribution is uniform, controlled by the output of each emitter.
- Variation in supply can be regulated by regulating the valves and drippers.
- Foliage remains dry, reducing the risk of disease.
- Usually operated at lower pressure than other types of pressurized irrigation, reducing energy costs.
Disadvantages of drip irrigation system
- Relative high Initial cost for the purchase of drip components.
- Sun UV light is the challenge that scorch up the drip tubing or the emitters like arrow drippers thus shortening the lifespan of these tubing.
- Drip irrigation systems cannot be used for damage control by night frosts.
- The risks of degrading plastic affecting the soil content and food crops. With many types of plastic, when the sun degrades the plastic, causing it to become brittle, the cancer chemicals (that is, chemicals replicating female hormones) which would cause the plastic to retain flexibility have been released into the surrounding environment.
- If the water is not properly filtered and the equipment not properly maintained, it can result in clogging of the drip emitters.
- For subsurface drip the irrigator cannot see the water that is applied. This may lead to the farmer either applying too much water (low efficiency) or an insufficient amount of water
- Drip irrigation might be inappropriate for some fertilizer application on some plants that require sprinkler irrigation for activation.
- Drip tape causes extra cleanup costs after harvest. Users need to plan for drip tape winding, disposal, recycling or reuse.
- Waste of water, time and harvest, if not installed properly. These systems require careful study of all the relevant factors like land topography, soil, water, crop and agro-climatic conditions, and suitability of drip irrigation system and its components.
- Most drip systems are designed for high efficiency, meaning little or no leaching fraction. Without sufficient leaching, salts applied with the irrigation water may build up in the root zone, usually at the edge of the wetting pattern. On the other hand, drip irrigation avoids the high capillary potential of traditional surface-applied irrigation, which can draw salt deposits up from deposits below.
- The PVC pipes often suffer from rodent damage, requiring replacement of the entire tube and increasing expenses.
NB; rodents damage to the pipes can be controlled by using high density polyethylene pipes (PE pipes) since they are stronger and structurally modified as compared to PVC pipes
Clearing of the bushes and application of the insecticides also keeps the rodents away.
Acid treatment for unblocking drip line in drip irrigation system
Unblocking the clogged drip tape/ drip line has become a major issue in the irrigation field. The cost of unblocking the clogged drip tape/drip line has also increased thus making the cost of production high.
However, the use of physical water flashing and chemical treatment has become a commonly used remedy.
In unblocking the clogged drip tape/drip line, one has to estimate the number of emitters. Drip tape varies according to the numbers of emitters along with the tape in terms of spacing. The spacing is dictated by the crop to be planted. Spacing can either contain a double emitter or a single emitter.
The emitters can be blocked due to bacterial build up in the system or presence of large sand particles or silt deposits in the system that may find their ways during drip tape installation process or during changing of either part of the system such as mainline, drip tape fittings or drip tape itself.
Steps in unblocking the clogged drip tape/line emitters using acid treatment
- Fill a ten liter (10 liters) PLASTIC BUCKET/CONTAINER halfway with cold water
- Carefully add fifty millimetres (50ml) of either of 33% hydrochloric acid or 85% phosphoric acid into the plastic bucket and stir the mixture with a plastic or wooden stirring stick to form a uniform solution.
- Avoid metallic stirrers since they cause corrosion.
- Continue adding the acid until the desired solution pH of 2.0 is obtained. If the pH is still low enough, continue pouring small amounts of acid slowly while observing the pH strip dipped into the bucket. The testing of the PH is done by dipping the PH strip with a scale on it into the solution. Ph testing strip can be obtained from recognized agro vets or chemist.
- Connect the mainline which usually runs from the water source into the bucket containing acid water solution. In case you have a bigger drip system that has a well or a tank as a water source, pour the acid- water solution into that source (a well or a tank).
- Open the gate valve at the water source or when using a water pump, turn the water pump on and run the irrigation system for at least an hour. This will ensure the acid-water solution is brought into the system through the mainline and this will clear up the bacterial buildups within the system.
- After acid –water solution flushing into the system, connect the mainline back into the initial water source and flush the entire system ones more with fresh water for at least forty five minutes (45 min). This will ensure the remaining acid solution that was left in the mainline and the drip tapes are flushed out.
- Store the remaining chemicals and used containers away from reach of children, sunlight. Store the remaining acid in a well-ventilated room and away from other flammable products.
- Hydrochloric acid and phosphoric acid are very dangerous if ingested or spilled.
- If you want to dispose of the remaining chemicals, take them to the disposal center or neutralize it using sodium chloride before pouring it out to drain
- Read and re-read acid instructions on the labels or the container.
- NEVER use both hydrochloric acid and phosphoric acid at ones. Use only one acid at a time
- The acid treatment is ideal for plastic pipes rather than metallic pipes
Physical unblocking of drip line in irrigation system
Flushing the system with water will ensure the large particles and other minerals present in the line are washed out. This can be done at least three times (3) per season. The period of flushing can be after land preparation and drip installation, mass water application of water especially during the budding stage and after fertilizer application. This will ensure no mineral deposits or bacterial build up in the system will be available to block the emitters.
After flushing the system with water, ensure the filters, mainline end caps and drip line end caps are placed back to the initial positions. Also, ensure the system’s filters are washed to avoid dirt build-up.
NB: the water should flow freely from these and mainline emitters and notice the color of the water while flowing out or flushing. It is very normal for the initial watercolor before flushing to be brown and clear after flushing.
If water does not clear after twenty (20) minutes of flushing it simply means there is likely of the system to be affected by the bacteria build up hence resolve to chemical flushing or treatment.
Materials needed for the best drip irrigation system
The materials needed for the best drip irrigation system are just basic piping equipment which include pipes (preferably HDPE pipe), none return valves (ball corks), water filters, ball valves air release valves, elbows, irrigation tees, drip tapes, drip fittings and any other relevant equipment.
The most recommended pipe for the best drip irrigation system is the HDPE pipe as it has minimum damage chances, minimum internal roughness hence minimizing frictional loss, more accurate internal diameter hence high accuracy on design
It is important to consult a recognized organization like Eunidrip irrigation systems on https://eunidripirrigationsystems.com/contact/to offer you the right information about the best drip irrigation system as small errors in a system may lead to high cost of maintenance and daily cost of running.