One of the most significant investments a farmer makes is the design and installation of an effective irrigation system. And one of the most common irrigation system challenges is preventing irrigation emitter clogging. These emitters are usually small, so it is not a matter of IF they will get clogged but rather a matter of WHEN and HOW.
Clogging can severely degrade irrigation system performance, which in turn leads to significant impacts on labor to correct issues or in production quantity and/or quality. It is important to understand the potential causes of clogging in order to take preventative measures.
Main causes of emitter clogging in irrigation systems
There are three main categories of emitter clogging: physical, biological and chemical.
Sand particles and suspended solids that are too large to pass through emitter openings are the most common physical cause of clogging. Silt and clay particles do not generally cause plugging unless they clump together (flocculate) and form larger masses.
Individual algae cells and bacteria are too small to clog emitters, but irrigation systems provide a favorable environment for the formation of biological aggregates such as bacterial slime. Bacterial slime can be a direct cause of clogging and it can also cause physical particles to stick together and form aggregates large enough to clog emitters.
Clogging related to algae and bacteria is common when water with high biological activity is used for irrigation, and is increased when iron, manganese and sulfide are present in the water.
In addition to algae and bacteria, surface water can also contain larger biological organisms, such as snails, plants and moss that can clog emitters.
Mineral precipitation from water sources with high mineral content (hard water) can produce suspended solids which clog emitters. Mineral precipitation occurs when mineral solubility is low and when factors such as water temperature, pH level, redox potential and mineral concentration in the water are favorable.
The most common elements that cause emitter clogging through precipitation and sedimentation are calcium, magnesium, iron and manganese – with calcium carbonate being the most common precipitate. Water with a high concentration of these elements and a pH of above 7.0 has a high potential for producing emitter clogging particles.
The addition of fertilizer(s) to source water (fertigation) can also be a potential cause of emitter clogging. Chemical interactions between the fertilizer(s) and hard water can increase the occurrence of mineral precipitation.
The connection between water source and emitter clogging
The water source you are using directly influences the emitter clogging hazards you are likely to experience.
Preventing emitter clogging is vital to protecting your investment in an effective and uniform irrigation system and ensuring production quantity and quality. It is important to understand the potential for clogging in each water source and the types of clogging you may encounter in order to evaluate methods for emitter clogging prevention.
Stay tuned for our next post, which will cover tools for preventing emitter clogging.