If you are suffering from clogged irrigation systems and their low-pressure performance, follow this article closely to find the solution.
Clogging is a critical issue that impacts the performance of drip irrigation systems and their efficiency. Irrigation systems clogging is formed rapidly due to insufficient pressure or poor water quality, which not only disrupts the uniformity of water distribution but also leads to inadequate irrigation. Clogging is a common and well-known issue in emitters, with many showing inadequate performance after just 2 or 3 years which affects their consistency and efficiency (Yavuz et al., 2010).
According to the International Organization for Standardization (ISO), clogging is defined as occurring when an emitter’s actual flow rate falls below 75% of its design flow rate, which decreases irrigation system efficiency and performance (EP405.1, 2003). Clogging in irrigation systems is influenced by several factors, with water quality playing a significant role. Due to water scarcity and pollution, a variety of low-quality water sources, such as reclaimed water, saline water, and high-sediment water, are increasingly used in irrigation. Emitter clogging is a process where solid particles, chemical precipitates, microorganisms, and other substances present in irrigation water accumulate within the laterals or emitters of a drip irrigation system, which leads to reduced irrigation flow rate and uniformity (Shi et al., 2022). The primary clogging substances include solid particles that directly block flow, calcium, and magnesium carbonate precipitates that cause chemical buildup, and biological materials like PLFAs and EPS that promote microbial growth and biofilm formation (Li et al., 2018). This article explores practical and effective physical, chemical, biological, and mechanical methods and solutions to prevent clogging and maintain various irrigation systems in the short and long term.
Table. Solutions to Prevent & Treat Irrigation Systems from Clogging (Brief Table)
Solution | Advantages | Limitations |
Filtration of Irrigation Water | Captures sediment and biofouling agents | Ineffective against fine particles |
Lateral Flushing | Enhances hydraulic shear forces | Does not completely eliminate clogging |
Magnetization of Irrigation Water | Increases average discharge from drippers | Efficacy influenced by water salinity |
Molecular Oscillation | Autonomous operation after installation | Limited availability and accessibility |
Intermittent Fluctuated Water Pressure (Pulsating or Dynamic Pressure) | Reduces clogging by promoting self-cleaning | Requires precise control of pressure cycles |
Ultrasound Water Treatment (Greendrum Technology) | Chemical-free approach to prevent and reduce clogging | Requires specialized ultrasound equipment |
Proper Pressure Regulation | Reduces risk of clogging with high-sediment water | Low pressure increases clogging risk |
Chlorination for Bio-Clogging Control | Controls microbial growth effectively | Regular monitoring required |
Acidification for Chemical Clogging | Reduces salt precipitation and chemical clogging | Regular monitoring required |
Fertigation | Some fertilizers can lower water pH, reducing clogging risk | Requires careful fertilizer selection to avoid clogging |
N-halamine Nanoparticles for Antifouling | Prevents biofilm formation, reducing clogging risk | Requires periodic reactivation with chlorination |
Electrochemical Treatment Methods | Reduces physio-chemical and biological fouling effectively in treated or reclaimed water systems | Effectiveness declines with prolonged use due to anode degradation |
pH Level, Hardness, and Ions Testing and Adjustment in Water Sources | Reduces mineral precipitation and clogging | Acid treatments require careful handling for safety and equipment protection |
Antagonistic Bacterial and Microbial Strains | can significantly reduce clogging by inhibiting clogging microorganisms | Most effective at early clogging stages |
Download Full Detailed Table of Table. 1. Solutions to Prevent & Treat Irrigation Systems from Clogging
1. Physical Methods
In order to ensure optimal performance and longevity of irrigation systems, implementing physical methods for the prevention of irrigation system clogging is crucial. These methods focus on enhancing water quality and flow dynamics to minimize the accumulation of debris and sediment that can lead to emitter blockages.
Physical methods include filtration of irrigation water, lateral flushing, magnetization of irrigation water, molecular oscillation, intermittent fluctuated water pressure, ultrasound water treatment, and proper pressure regulation, reducing the risk of clogging in irrigation systems.
1.1. Filtration of Irrigation Water
Filtration is essential in preventing clogging in irrigation systems by capturing sediment and biofouling agents. Commonly used filter types, such as sand, disk, and screen filters, are essential to prevent irrigation system clogging by pre-screening and filtering sediment loads in irrigation water (Ramachandrula and Kasa, 2022). However, high levels of sediment, organic matter, and microorganisms can rapidly lead to composite clogging in drip emitters. Rapid clogging and filter malfunction are frequently observed during peak periods of biomass growth, with filter performance varying significantly based on the type of filtering element, hydraulic characteristics, and specific design features. In terms of effectiveness, filters typically remove less than 1% of total suspended solids (TSS) in inlet water, focusing primarily on large, rigid particles or aggregates. Zooplankton removal rates vary by species; for instance, daphnia is generally removed effectively, copepods moderately, and rotifers less effectively. While increasing the filtration level of a filter can improve downstream protection, it also leads to faster pressure loss across the filter. Early detection of clogging and regular monitoring of pressure and flow rates is crucial, particularly when using irrigation water sourced from sewage, to alleviate clogging problems before they escalate (Ravina et al., 1997)
Filter types significantly influence clogging in emitters, and interactions between irrigation pressure and filters affect system operation and drip performance (Liu et al., 2022). High-sediment water often leads to composite clogging in irrigation systems, which affects emitter performance and system efficiency. While settling tanks reduce clogging risk by lowering particle loads, a Horizontal Roughing Filter (HRF) significantly reduces clogging substances and improves irrigation system performance, lowering sediment and organic loads by 73.6–89.6% and improving uniformity and discharge by up to 27.1% and 22.5%, respectively (Liu et al., 2021).
1.2. Lateral Flushing
Lateral flushing is an effective strategy for mitigating emitter clogging in drip irrigation systems, particularly when using reclaimed water. This method enhances hydraulic shear forces within the laterals, promoting the detachment of biofilms from the emitter walls and minimizing their transfer into the emitters during operation. Regular flushing can significantly reduce clogging rates; for instance, different flushing frequencies (weekly, biweekly, and triweekly) affect discharge ratios and the presence of clogging materials. In experiments, biweekly flushing yielded the best results, reducing solid particles and biofilm components, although it did not completely eliminate clogging issues (Li et al., 2015). Additionally, flushing treatments, reducing clogging for 16 types of drip irrigation system emitters, have demonstrated improvements in the average discharge ratio and coefficient of uniformity across various emitter types of high-sediment irrigation systems, with flat and cylindrical emitters showing the most significant operational advantages. While lateral flushing enhances emitter performance and extends operational hours, combining this method with other measures may be necessary for comprehensive clogging management (Ma et al., 2024).
Utilizing freshwater for flushing significantly reduces emitter clogging compared to treated effluent, controlling sediment buildup in drip irrigation systems. Flushing with freshwater is suggested to use after every five irrigation events when using treated effluent since it reduces calcium and magnesium deposits, and creates an unfavorable environment for bacterial growth (Li et al., 2019). However, Lateral flushing proved ineffective in preventing severe clogging of emitters when using saline groundwater. To address this challenge and enhance the prevention of irrigation system clogging, the use of freshwater for flushing post-irrigation and extending flushing duration is recommended, which needs further investigation into optimal strategies for managing and preventing saline-induced clogging (Feng et al., 2017).
1.3. Magnetization of Irrigation Water
Magnetization irrigation water is performed by the transition of irrigation water using a robust permanent magnet connected to a feed pipeline. Magnetization of irrigation water has been shown to enhance the performance of drip irrigation systems. When compared to non-magnetic water, the use of magnetic water resulted in increased average discharge from drippers, indicating a reduction in clogging and improved distribution uniformity. The type of irrigation water and its salinity significantly influenced dripper discharge averages. Magnetic water positively impacted various performance metrics, including average dripper discharge, distribution uniformity, emission uniformity, and Christiansen’s uniformity coefficients. In non-magnetic water treatments, the average reduction in distribution uniformity reached 10% by the final irrigation, while the magnetic water treatment only experienced a 2% reduction. Therefore, using magnetized water can effectively address clogging issues, particularly when saline water is applied (Khoshravesh et al., 2018).
Magnetization of irrigation water can improve emitter performance in drip fertigation systems as an innovative solution to address water scarcity and enhance fertilizer efficiency where emitter clogging remains a significant challenge that hampers their effectiveness. Compared to untreated water, magnetized water led to a higher discharge ratio and coefficient of uniformity, while simultaneously reducing the accumulation of clogging substances, particularly mineral components such as phosphates, silicates, and quartz. Magnetized water treatment significantly decreased the contents of chemical and particulate fouling by 53.17–74.80%. As the dominant clogging agents, quartz, silicate, and carbonate were effectively reduced through magnetization, which highlights its potential as a chemical-free approach for controlling clogging and advancing drip fertigation technology while minimizing environmental impact (Shi et al., 2023; Shi et al., 2022).
1.4. Molecular Oscillation
Molecular oscillation technology, exemplified by the Merus ring developed by the Merus Company in Germany, offers a novel approach to mitigating emitter clogging in trickle irrigation systems. This metallic device is installed on the feed pipeline, and emits specifically modulated molecular oscillations that alter the natural molecular vibrations of substances in the water. Unlike traditional methods that rely on external energy sources or magnetic fields, the Merus ring functions autonomously after installation, continuously preventing sediment accumulation and chemical precipitates. Emitters equipped with the Merus ring exhibited significantly improved hydraulic performance compared to those without it, particularly in terms of average emitter discharge and distribution uniformity. Treatments utilizing the Merus ring maintained higher discharge ratios even as water salinity increased. This technology effectively disintegrates clogging materials, allowing them to be flushed out of the system, thus proving to be a practical solution for reducing emitter clogging and enhancing irrigation efficiency across varying salinity levels (Barati et al., 2014).
1.5. Intermittent Fluctuated Water Pressure (Pulsating or Dynamic Pressure)
The use of intermittent fluctuated water pressure, or pulsating dynamic pressure, has shown significant improvement in controlling clogging in drip irrigation systems, particularly when using high-sediment water. By periodically increasing the pressure within the system, the accumulation of clogging materials, such as clay particles, silicates, and calcium-magnesium carbonates, can be reduced. Applying a fluctuated pressure treatment for 4 hours at 80–100 kPa, following a stable pressure of 40 kPa for 16 hours, yielded effectively minimized the presence of clogging materials: clay particles decreased by 26%, fine particles by 56%, quartz by 34%, silicate by 36%, and carbonate deposits by 35%. The system’s discharge ratio and coefficient of uniformity increased by 16.7% and 14.2%, respectively. This pulsating technique works by altering flow velocity, preventing the formation of deposits in emitters, and promoting a self-cleaning effect along the lateral walls. Consequently, pulsating pressure is an effective strategy to mitigate emitter clogging and maintain system efficiency (Li et al., 2019).
The use of intermittent fluctuated water pressure with a trigonometric function waveform in labyrinth channels significantly enhances anti-clogging performance by reducing particle residence time, minimizing deposition, and increasing turbulence in stagnation zones, thereby improving particle transport and maintaining flow capacity in drip irrigation systems (Chao et al., 2017). Applying intermittent pulsating pressure enhances water distribution uniformity in sprinkler irrigation on sloping land by reducing the uphill and downhill throw disparities, improving the Christiansen Uniformity Coefficient (approximately 10% for a single sprinkler) compared to constant pressure (Zhang et al., 2019).
1.6. Ultrasound Water Treatment (Greendrum Technology)
Greendrum technology, an innovative ultrasound-based system effectively cleans and maintains drip irrigation lines without using chemicals. This environmentally friendly approach applies high-frequency ultrasound in a water bath, which loosens dirt particles within drip lines and emitters, allowing them to be flushed out during cleaning. Evaluations with different emitter models demonstrated significant improvements in irrigation uniformity. The coefficient of variation in emitter discharge dropped from 10.6% to 2.85%, restoring the lines to near-original performance. This technology preserves water resources by ensuring efficient drip line functionality over time, with Agricultural Research Council–Institute for Agricultural Engineering (ARC-IAE) field tests validating its effectiveness in maintaining emitter performance and prolonging irrigation system life (Reinders and Van Niekerk; 2018). An innovative chemical-free ultrasonic water treatment using radio frequencies can also prevent clogging from saline groundwater in drip irrigation, improving uneven water distribution and efficiency (Ghandour et al., 2024).
1.7. Proper Pressure Regulation
Operating pressure and implementation of proper pressure regulation impact on emitter clogging of drip irrigation system. While lowering operating pressure in drip irrigation can reduce energy costs, using low pressure with high-sediment water can significantly raise the risk of emitter clogging, potentially offsetting these savings with increased maintenance needs. Emitter anti-clogging performance in drip irrigation systems with high-sediment water declines gradually when operating pressure falls below 100 kPa, but the decline accelerates significantly below 60 kPa due to increased clogging substance formation. Thus, maintaining operating pressure above 60 kPa is essential for effective anti-clogging performance (Liu et al., 2019).
2. Chemical Methods
Chemical methods are effective for controlling various types of clogging in irrigation systems, including bio-clogging, chemical precipitation, and fouling caused by poor water quality. These approaches, such as chlorination, acidification, fertigation, and electrochemical treatment, are designed to mitigate clogging risks by targeting microbial growth, adjusting water pH and hardness, and preventing mineral deposits, which are discussed in detail below:
2.1. Chlorination for Bio-Clogging Control
Chlorination is an effective method for controlling bio-clogging in drip irrigation systems, particularly when using reclaimed water. In a recent study, three chlorination treatments were tested to determine the best approach for minimizing microbial growth in non-pressure-compensating emitters. The treatment of 2.5 mg/L chlorine over two hours (low concentration, long duration) was found to be the most effective. This method reduced microbial phospholipid fatty acids (PLFAs) by up to 36%, microbial activity by 23%, and extracellular polymeric substances (EPS) by over 40%, all of which contribute to biofilm formation. Chlorine’s strong oxidizing properties help control microbial colonies and reduce solid particle content, which improves the uniformity and discharge ratio of the irrigation system (Song et al., 2017). This low-dose, extended chlorination method is a cost-effective approach, especially in sewage applications where algae and protozoa accumulate (Dehghanisanij et al., 2005), making it a practical solution for systems using treated wastewater. Regular, low-concentration chlorination treatments are generally more effective than infrequent, high-dose treatments, as they help control biological clogging agents and sustain emitter performance over time (Li et al., 2010).
2.2. Acidification for Chemical Clogging
Acidification is an effective method for managing chemical clogging in drip irrigation systems, particularly where salt precipitation occurs. By injecting acid, water pH can be lowered to prevent the formation of precipitates that commonly cause clogging. Acidification and acid treatment can outperform methods like magnetization irrigation water, which significantly reduce flow rate reductions in emitters using acidic water (Ahmadaali et al., 2009). Acidification has also been effective in reducing clogging caused by secondary sewage effluent with various ion types, where lowering pH to 6.5 minimized the buildup of biofilms and solid particles (Hao et al., 2018). However, specific emitters, such as plain channel designs, benefit more from acid treatments compared to labyrinth structures, which tend to clog more. Additionally, organic acids like acetic and formic acid should be avoided as they can inadvertently promote the growth of clogging agents like Trichoderma fungus, potentially exacerbating clogging issues rather than mitigating them (Kreij et al., 2003).
2.3. Fertigation
Fertigation, which involves delivering fertilizers through a drip irrigation system, helps optimize nutrient application and minimize waste, which lower costs for farmers. While fertigation can improve plant health and the system's hydraulic performance, it also requires careful selection of fertilizers to prevent emitter clogging. Fertilizers like ammonium phosphate, which can increase water alkalinity, should be avoided as they may exacerbate clogging by promoting precipitation within the system. Instead, fertilizers that lower water pH are generally preferable, as they help dissolve potential blockages. For example, urea phosphate at low concentrations has been shown to be effective in reducing clogging problems, enhancing both nutrient delivery and system efficiency. By balancing nutrient application with clogging prevention, fertigation offers a dual benefit, making it one of the most widely studied chemical methods for maintaining drip irrigation systems (Ramachandrula and Kasa, 2022).
2.4. N-halamine Nanoparticles for Antifouling
N-halamine Nanoparticles have emerged as a promising solution for drip irrigation systems, especially those using treated wastewater, which often leads to biofouling and clogging. N-halamine-derivatized cross-linked polymethacrylamide NPs are developed and embedded within the polyethylene used to fabricate drip emitters. These nano-functionalized drippers are activated by chlorination with sodium hypochlorite and demonstrate significant resistance to biofilm buildup. In field tests, the NPs maintained antifouling effectiveness for at least five months, highlighting their durability and potential cost-effectiveness. Additionally, these NPs are rechargeable, allowing them to be reactivated with chlorination for prolonged use. This innovative approach helps maintain efficient water flow in drip systems, reducing the risk of emitter clogging and extending the system lifespan, making it a valuable technology for sustainable irrigation with treated wastewater (Natan et al., 2019; Ramachandrula and Kasa, 2022).
2.5. Electrochemical Treatment Methods
Electrochemical treatment has proven effective in preventing clogging in drip irrigation systems, particularly when using treated or reclaimed water, which can lead to physio-chemical and biological fouling. This treatment is designed by a low-voltage electrolysis unit, using titanium and stainless steel as the anode and cathode, respectively. The best results occurred at 4 V and a 48-hour treatment, achieving a bacterial reduction rate of 66.85% and a hardness removal rate of 23.93%, with an optimal accumulated treatment time of 160 hours. However, after prolonged operation beyond 320 hours, the effectiveness of this method declined due to the degradation of the Ti/SnO₂+Sb₂O₃ anode. This solution and technology require improvements in reactor design and anode stability to enhance long-term performance. This method offers a clean, low-cost, and environmentally friendly alternative to chemical treatments, with significant potential for large-scale irrigation applications ( Zhang et al., 2017).
2.6. pH Level, Hardness, and Ions Testing and Adjustment in Water Sources
Maintaining optimal pH levels, reducing hardness, and managing ion concentrations are crucial to prevent clogging in irrigation systems, especially when using saline or reclaimed water. High pH water can cause chemical clogging due to mineral precipitation, while hardness (resulting from calcium, magnesium, and other ions) further accelerates this process. Acidic treatments are often employed to lower the pH of irrigation water to prevent clogging. There are two primary approaches: first, maintaining a weakly acidic environment by adding acidic reagents to keep the pH around 6.5, which minimizes precipitation; and second, performing short-term, intense acid injections to dissolve existing mineral deposits, bringing the pH down to about 3.0 temporarily. However, acid treatments require careful handling to protect equipment and crops, and standards set by the American Society of Agricultural Engineers should be followed for safety. Regular system flushing after acid treatments prevents further deposit buildup. Common acids like sulfuric and hydrochloric acid are effective at lowering pH and mitigating clogging, while organic acids and certain fertilizers can also be used. Implementing these adjustments, combined with filtration and periodic monitoring, helps sustain emitter performance and irrigation efficiency (Shi et al., 2022).
3. Biological Methods
Biological clogging in drip irrigation systems occurs as biofilms form inside drippers, which reduce water flow and potentially block the irrigation system. This process begins when bacteria in the water attach to dripper walls, secrete extracellular polymeric substances, and create a biofilm matrix that resists detachment by water movement. Factors like organic matter, nitrogen, and phosphorus promote bacterial growth, particularly in reclaimed wastewater (Petit et al., 2022). Introducing antagonistic bacterial and microbial strains has shown promise in reducing biofilm formation, which is discussed in detail below:
3.1. Antagonistic Bacterial and Microbial Strains
Antagonistic bacterial strains have shown promising results in combating biological clogging in drip irrigation systems. Studies have demonstrated that certain strains, such as Bacillus spp. and Burkholderia spp., can effectively reduce the growth of clogging-inducing microorganisms. In controlled experiments, drip irrigation emitters exposed to bacterial and fungal isolates experienced restored flow rates after treatment with these antagonistic strains. Specifically, Bacillus strains inhibited fungal growth and reduced bacterial clogging agents, while Burkholderia strains suppressed bacterial and fungal contaminants more comprehensively. Within two weeks, emitters treated with these antagonists achieved their original discharge rates. These bacterial strains hold significant potential as eco-friendly, anti-clogging agents in irrigation systems. This approach provides an alternative to chemical treatments by leveraging natural microbial interactions to maintain emitter efficiency (Şahin et al., 2005).
Microbial antagonism is an innovative approach for controlling biofilm formation and preventing clogging in drip irrigation systems that use reclaimed water. This solution involves using antagonistic bacteria, such as Bacillus subtilis, to inhibit biofilm-forming microbes, significantly reducing clogging. Studies indicate that microbial antagonism can decrease biofilm formation by around 62% and extracellular polymeric substance content by 14%, which helps maintain water flow and enhances overall system performance (Wang et al., 2022). In particular, this method proves most effective when applied at early stages of clogging, as it slows microbial adaptation. Controlling the dominant gram-positive bacteria within biofilms, including Pseudomonas, is especially beneficial, given their high efficiency in decomposing organic matter, which accelerates clogging. Tracking microbial communities within emitters has shown that addressing these bacteria’s growth can effectively reduce clogging issues. By preventing clogging, microbial antagonism improves the efficiency of reclaimed water use in agricultural irrigation, which ultimately decreases system maintenance costs and prolongs the life of irrigation infrastructure (Zhou et al., 2017)
4. Preventive Maintenance Practices
Clogging in drip irrigation systems presents several challenges due to the different types (physical, chemical, and biological) that each requires specific maintenance approaches. Effective clog management begins with identifying the type and extent of clogging in the field, yet this is often complicated. Laboratory methods can provide insight into clogging mechanisms but are limited by sample extraction requirements or specialized setups like transparent flow cells, which can be impractical for regular field use. Field-based hydraulic measurements offer indirect clogging estimates but lack sensitivity to detect early-stage clogs accurately. Detecting clogging directly within drippers remains challenging due to the diversity of clogging materials and the narrow dripper channels (around 1 mm²). While no direct detection method currently exists for field applications, advanced sensors, such as electrical, mechatronic, acoustic, and optical types show promise for future clogging diagnostics (Petit et al., 2022). Due to the limitations of irrigation system clogging treatments (physical, chemical, and biological methods) as well as the challenges of clogging diagnostics, it is crucial to take preventive maintenance practices.
Using self-cleaning or clog-free emitters and sprinklers is an effective preventive measure to reduce clogging in irrigation systems, particularly when dealing with dirty water sources like ponds or irrigation ditches. Traditional fine-screen filters often clog quickly with large particles, leading to inefficient irrigation and frequent maintenance. To address this, reliable non-plugging emitters, such as those from DripWorks, are designed to pass particles that would typically clog conventional emitters, improving system reliability and reducing maintenance frequency. These emitters can be paired with a coarse filter (30-50 mesh) to trap only the largest particles, allowing the emitters to handle smaller debris without clogging (DripWorks). Additionally, adjustable irrigation drippers with self-cleaning capabilities, like those from MSDADA, feature automatic cleaning mechanisms and anti-clogging channels. The initial water flow through these emitters actively clears potential blockages, ensuring a smooth operation over time. This technology provides a cost-effective solution for maintaining uniform water distribution, even when the water supply is less than pristine (MSDADA).
5. Conclusion
Maintaining optimal performance in irrigation systems requires a comprehensive approach to prevent clogging, which can significantly impact efficiency and increase maintenance costs. The solutions and methods discussed in this article include physical, chemical, and biological approaches, each tailored to specific clogging causes (physical, chemical, and biological). Physical methods like filtration, lateral flushing, and regulating water pressure address sediment and particulate buildup. Chemical treatments and methods, including chlorination, acidification, and pH adjustments, mainly target mineral deposits and bio-clogging, while innovative options like N-halamine nanoparticles and electrochemical treatments provide advanced antifouling solutions. Biological methods, particularly the use of antagonistic bacterial strains, offer an eco-friendly approach to managing biofilm formation and reducing microbial clogging risks in reclaimed water systems. Preventive maintenance practices, such as regular inspection and testing and using self-cleaning or clog-free emitters and sprinklers, are critical to ensure early detection of potential issues or sustain system efficiency. By combining these diverse treatment methods of irrigation system clogging, irrigation systems can remain functional and effective minimize water wastage, and extend system lifespan. This multifaceted strategy will not only enhance performance but also promote sustainable agricultural practices and resource conservation, contributing to improved irrigation management and efficiency.