Drip Irrigation Inspection Checklist for Agriculture

New Jersey farmers use a variety of methods to deliver water to their plants. An increasing number of farms use drip irrigation systems designed to deliver water from a feed hose or pipe through tubing/tape that deliver water directly to the plants' root zone by slowly trickling out onto the soil. Drip irrigation systems are viewed as the most efficient irrigation method (NRCS 2005).

Causes of Clogging

One maintenance issue that affects drip irrigation is the clogging of both the tubing/tape in the field and the water emitters used to deliver the irrigation water to the soil and plants. Though most drip irrigation tubing/tape have proprietary 'turbulent flow' emitters to reduce the potential for clogging, sand and sediment particles not properly filtered from the water source or from chemical components in the water may occasionally overtax those systems. Some of these chemicals are dissolved solids, such as iron, sulfur, and calcium, which originate from the rocks and soil in the aquifer from which the water is drawn (Storlie 1995; Zinati and Shuai 2005). These dissolved solids can precipitate, with the solids being deposited in the irrigation system, under the proper acidic or oxygenated conditions. Clogging can irreversibly damage the irrigation systems costing time, money, and lost crops due to the failure of the system to properly irrigate the plants. Therefore, drip irrigation systems should be inspected regularly.

Drip Irrigation System Checklist

The checklist provided below is a quick and easy tool to visually assess the functioning of drip irrigation systems. Any time that you check 'Yes' to a question it may indicate there is a clogged emitter or line, or that there is the potential for clogging. Follow-up inspections or monitoring of the irrigation water quality should be done to pinpoint the exact nature of the clogging agent.

When using this checklist, the following guidelines are recommended:

1. Conduct regular visual inspection of the plants for signs of lack of water (i.e., wilting and/or dry, brown leaves) and visually inspect the soil for dry areas adjacent to drip lines and emitters; these are indicators of clogging. Take note of any patterns of dry/wilted plants–1-2 wilted plants may indicate a clogged emitter, while a part or whole row of wilted plants likely indicates a clog in the tubing/tape itself.
2. Periodically visually inspect the irrigation water in the field. If not using autoflush fittings, open the ends of the drip lines during irrigation to help remove any buildup of particles and other debris that can lead to clogging.
3. Perform routine cleaning and/or replacement of pump filters to reduce the accumulation of sediment and other debris.
4. Keep a record of the date, location, and number of visual inspections made and a description of what was observed.

Drip System Maintenance

If problems are discovered after using the checklist, the following examples of maintenance actions can help correct some of the problems encountered.

Flushing

Periodic flushing to prevent clogging from sediments or other materials can help remove fine particles not filtered from the source water. Regular flushing scheduled into a farm's irrigation management plan will prevent many of the problems observed by using this checklist. Fine sand, silt, and clay or fine particles of algae can be small enough to pass through filters and deposit in the drip tubing/tape and even in the water emitters. Flushing may be accomplished automatically during each irrigation cycle if using autoflush fittings.

To flush the tubing/tape lines, open the ends of the tubes and allow the water to discharge for several minutes or until it runs clear, if water color was an issue, to carry any deposited materials. The key to adequate flushing is to provide an open-line flushing velocity of at least 1 foot per second at the end of the drip line.

Water Sampling

An essential part of preventative maintenance in any irrigation system is water sampling. If the cause of clogging is unknown, sampling results can pinpoint the cause and targeted solutions implemented. Sampling should be done at a frequency to sufficiently monitor water quality parameters that may indicate clogging (for example, iron). Usually once a season is enough, but if levels are high enough, monthly samples may be needed. For more on the use of water testing to maintain drip irrigation, see the Rutgers NJAES fact sheet Using Irrigation Water Tests to Predict and Prevent Clogging of Drip Irrigation Systems. Simple and inexpensive test kits may be purchased from companies such as Hach or LaMotte.

Chlorination

Chlorination is the addition of a chlorinating compound, either a solid calcium hypochlorite or liquid sodium hypochlorite. Chlorination will cause iron in the water to precipitate and allow the iron particles to be filtered from the system. The chlorine will also kill any bacteria and algae that may be growing in any of the parts of the drip irrigation system. For the treatment of iron, chlorination should be conducted continuously. Chlorination can be introduced into the irrigation system continuously or as needed to treat bacteria and algae buildup. For more on chlorination of drip irrigation water and to determine proper rates of chlorine addition, see the Rutgers NJAES fact sheet Treating Drip Irrigation Systems with Chlorine.

Replacing any component of an irrigation system may be a significant financial investment. Regular inspection and monitoring of the system as part of a farm's irrigation management program can protect this investment. This checklist can provide information to troubleshoot and prioritize maintenance, including flushing of the drip lines, prior to any large investment such as replacement of system components.

Drip Irrigation Inspection Checklist for Agriculture

	Yes	No
Are the leaves on the plants wilting? (If yes, the plants may not be getting enough water due to a clog in the system.)
Are the edges of the leaves on the plants brown and/or brittle? (If yes, the plants may not be getting enough water due to a clog in the system.)
Are the leaves on the plants turning brown in the areas between the veins? (If yes, the plants may not be getting enough water due to a clog in the system.)
Do plants block the spray pattern/emitter from reaching other plants? (If yes, the blocked plants may not get enough water.)
Do plant roots grow over or around lines and emitters? (If yes, the roots may prevent the plants from getting water.)
Are the emitters too far away from the plants? (If yes, the plants may not get enough water.)
Is there dry soil adjacent to the emitters during irrigation? (If yes, the line or emitter may be clogged.)
Is there standing water on the ground when irrigation pump is not running? (If yes, there may be a leak in the drip line.)
Are any emitters tilted or twisted in the wrong direction? (If yes, the emitter may not deliver water to the plants.)
Are any emitters too far in or above the ground? (If yes, the emitter may not deliver water to the plants.)
Is water leaving the emitter sporadically? (If yes, the emitter may be clogged.)
Open ends of drip lines to let irrigation water flow: Is the water brown or muddy looking? (If yes, the water at the source or in the line may have sediment.)
Open ends of drip lines to let irrigation water flow: Is the water a rust red or orange color? (If yes, the water at the source or in the line may have iron.)
Open ends of drip lines to let irrigation water flow: Is the water a greenish color? (If yes, the water at the source or in the line may have algae.)
Open ends of drip lines to let irrigation water flow: Is the water a white or milky color? (If yes, the water source or in the line may have bacteria.)
Is the line pressure higher-than-normal? (If yes, the water at the source or in the line may be clogged, increasing pressure.)

References

1. NRCS. 2005. New Jersey Irrigation Guide. United States Department of Agriculture, Natural Resources Conservation Service, Somerset, NJ.
2. Storlie, CA. 1995. Using Irrigation Water Tests to Predict and Prevent Clogging of Drip Irrigation Systems. Fact Sheet FS793. Rutgers University, New Jersey Agricultural Experiment Station, New Brunswick, NJ. 2p.
3. Zinati, G and X Shuai. 2005. Management of Iron in Irrigation Water. Fact Sheet FS516. Rutgers University, New Jersey Agricultural Experiment Station, New Brunswick, NJ. 4p.

May 2018