Subsurface tape installation

So, he headed to the one area of the farm holding old, used equipment. There he saw an 8-row cultivator. When the Montgomery County corn and soybean farmer saw it, he knew it would make the perfect piece of equipment to lay SDI tape. So, he set to investigating and designing his own version. Instead of using the entire 8-row cultivator, Winter cut it in half. The cultivator holds the shanks. The shanks dig into the ground.

They have a hollow nose where the black tape is fed into the hose reel. Realizing he could not create the shank tooth and shin guard used in laying the tape, Winter called Rain-Flo, a Pennsylvania irrigation company, and asked if the company would sell just the shanks. Winter also purchased the spool holder for the drip tape. Sometimes the unwrapping is done with a knife.

Careless or rough handling of the tape may lead to major leaks after installation. Lay the tape down with the emitters facing upward to avoid soil plugging. The rolls have indicators showing the direction of the emitters. Just before lowering the shank, anchor the tape temporarily by hand or with a stake so it can be pulled into the soil. Stakes can be made of welding rods or rigid wire Fig. The depth of the tape will depend on the crop. Tape has been installed 12 to 14 inches deep for permanent SDI systems in crops such as cotton and alfalfa in the St.

Lawrence, Trans-Pecos and Lubbock areas In the Lower Rio Grande Valley, tape has been installed 2 to 6 inches deep for vegetable crops such as onions and melons. Check to see that the tape is at the correct depth and adjust the control roller if necessary.

If the drip tape runs out in the middle of the field it must be spliced Figs. A 3- to 4-inch-long PVC tube can be used to splice the old and new rolls together by securing the tape to the ends of the tube using two stainless steel wires or special connections.

Trenching Trenching may be necessary for mainlines, manifolds and flush lines. The steps are as follows: Before trenching, pack the tape on the field with a tractor, passing a wheel on each side of the tape. The trenches for the submains should be at least 16 inches below the depth of the drip line and 1 foot below the flushing line.

Expose the tape from the ditch forming a triangle Fig. Leave enough space to work with the hands and tie the drip line to the PVC pipe. Level and pack the ditch bottoms with soil that falls from exposing the tape.

Place some flags where each station ends. Connecting drip lines with manifolds and flush lines If manifolds and flush lines are below the soil surface: There are several ways to make the connections. Drill a hole in the top of the manifold or flush line just where the tape is to be connected. Clean the hole with a knife to remove all plastic residue. This plastic could produce leaks later in the season.

Insert the grommets in the hole. Pre-assemble the insertion to the PVC hose, using glue. Soak the insertion with soapy water so it will fit easily into the grommet. Insert the PVC hose into the tape, being careful not to bend the hose. Tie a stainless steel wire around the tape Fig. If submains and flush lines are above the soil surface: The most common connection method is to insert small-diameter PE tubing 0.

Back-filling Run each station for 4 hours and check for leaks. Installing filtration equipment The filters should be installed over solid surfaces, preferably concrete bases. Follow these steps to install a sand media filter: Order only pre-washed gravel. Install the gravel and the sand at the depths recommended by the manufacturer. Close all the valves downstream of the tanks the back-flush valve.

Open the main valve butterfly valve. Open completely the back-flush valve of one of the media tanks. Then open the back-flush flow rate adjustment valve slowly. A rapid drop in line pressure can cause tubes to collapse or flatten. This is one of the drawbacks in a newly installed system, loose soil may settle around a collapsed tube, making it difficult for the tube to regain its shape, at the commencement of the next irrigation.

Drainage valves at the end of each tube at the end of the field are also essential for clearing small soil particles that have passed through the filter system and for draining the tubes at the end of the irrigation season. The tubes are inserted below the soil surface, using an attachment pulled by a tractor.

The placement depths vary from 6 to 24 inches, depending on the soil, top soil depth and crop. Shallow-rooted crops, like strawberries, may require placement as shallow as 3 to 4 inches below the surface. In these instances, place tape or tube closer to the surface to germinate seeds and sustain seedlings.

Otherwise, a portable sprinkler system should be available for seed germination. Placing subsurface irrigation deeper in the soil also enhances soil tillage benefits. In all cases, face the emitters on the tubes upward at installation. Once an emitter depth is decided on, consistent depth placement of tubing or tape is helps to achieve uniform soil-water content throughout the field but is not necessary if tubing has pressure-compensating emitters.

It is essential to have a filtration unit that will filter all the particles that are bigger than the emitter openings. As a rule of thumb, filters should remove particles four times smaller than the emitter opening, or as small as economically feasible; since particles my group and clog emitters.

A filtration system mainly consists of sand media filters; however, a combination of screen and disk filter with sand media filters is highly desirable. A screen filter installed before sand media filters several smaller sand media filters are better than one large filter will remove larger organic and inorganic debris e.

A mesh filter is adequate for most types of emitters although some drip tapes require only mesh. Filtration can be viewed as the heart of a subsurface irrigation system and should be designed properly by agencies mentioned above or your professional system supplier, to fit the level of contamination in the water source.

Filtration may not be a concern for subsurface irrigation in urban areas where domestic or higher quality well water is used. The performance and life of any system depends on how well it is designed, operated and maintained. Whether automatically controlled or otherwise, inspect the system regularly.

Another drawback is that plugged emitters are not noticeable until the plants are wilted. Also, rodents tend to chew the tubes, therefore use precaution to prevent rodent damage, or do not use a buried system where rodents are common.

Clogging is also not readily apparent, so you may choose to use acid solutions e. In Colorado, acid is most often used for flushing since it will also eliminate algae and carbonate lime build up.

Cleanout valves installed at the end of the tube lines are important to remove blockages and draining the system. The quality of water affects the system. High pH water will tend to precipitate a white calcium salt residue, especially with pressure changes that occur across subsurface irrigation emitters. Calcium and iron precipitates are a problem with most well waters. High salinity or iron concentrations in the water will also cause precipitates; which are aggravated by the presence of organic matter, bacteria and algae.

These will require more frequent flushing measures. Deep well water may be free of scum, but check the pH to avoid precipitate buildup. Other sources of emitter clogging can be plant roots that tend to grow into the small emitters. Emitter blockage is often a function of poor subsurface irrigation design, consult with CSU Extension or NRCS staff to ensure you have sized pumps, lines, filters and zones correctly.