Oakes Irrigation Research Site

Carrington Research Extension Center * North Dakota State University

P.O. Box 531, Oakes, ND 58474-0531, Phone: (701) 742-2744, FAX: (701) 742-2700, E-mail: Kelly.c.Cooper@ndsu.edu

Oakes Irrigation Research Site - Updates

Kelly Cooper

The Oakes Irrigation Research Site had a great year. Among the new projects and developments is a new water supply

system. A horizontal well was installed December 7, 2015. The horizontal well is a relatively new way of extracting irrigation

quantities of ground water in North Dakota. The well, as the name implies, runs horizontally to the surface for several hundred

feet buried some 20 feet deep by a modified trenching machine. The well pipe is actually a poly sock wrapped plastic drain

tile 8 inches in diameter. Several of these wells have been installed in the Oakes area during the last five years and most are

performing adequately. Success is never a guarantee with any well, and horizontal wells are no exception. Careful planning

is a must and drilling test wells along the intended length of the well is a requirement.

At the research site, we first looked up the logs of the test wells and existing wells near our intended installation area

on the North Dakota Water Commission website. These all looked positive, with sand or gravel extending down to 30 feet below

the surface. A requirement is to have no clay or silt layers between the installation surface and the depth of the well. Most

commonly, the top two feet of soil is excavated before installation which typically removes finer material. Our next step was

to pick a location and dig test wells every 100 feet along the intended path. The test wells are done by using high pressure

water forced through a 1½ inch plastic pipe which is forced into the ground by hand. The end of the pipe has a well screen

and a special valve which allows water to exit out the end of the pipe, but closes when suction is applied. The procedure also

shows how fast the aquifer will “take” water, which is a good indicator of hydraulic conductivity of the material and should

indicate how fast water can come into the well. The new test wells revealed a layer of silty clay four to six feet below the

ground surface extending for a couple hundred feet along the intended path of the well. Therefore, we decided to remove six

feet of material. This not only removed the fine textured material so it would not get mixed in next to the well pipe, but would

place the pipe farther into the aquifer. The water table at the time of installation was approximately 11 feet below ground level.

The trench was six feet deep, 15 feet wide, and 800 feet long plus a ramp which allowed the trencher to enter and exit.

Installation started with the attachment of the standpipe to the trencher. The drain tile was then threaded through the

trencher, much like threading a sewing machine. The drain tile or well pipe was then attached at the bottom of the stand pipe

at a 90 degree angle. With the standpipe loosely connected to the trencher, the trencher digging chain is activated and the

trencher digs its way into the ground as it is rotated into the vertical position. Once vertical, the trenching machine begins to

move, leaving the standpipe behind, stringing out the drain tile 20 feet below. The entire process took nearly 3½ hours to install

the 800 feet of tile. After conferring with several interested parties, we decided to tail up the end of the tile to ground surface

at the end of the well to allow access. Garrison Diversion Conservancy District has been cleaning its drain tiles on a regular

basis in the Oakes test area, and this will allow them to clean this well, if needed. Also, since this well is a relatively new

technology, there may be utility in allowing access for various test equipment that could be placed in the well to monitor

flow rates, iron bacteria build up, or silt infiltration.

Shortly after installation, the well was test pumped at 550 gallons per minute for 3½ hours. The draw down was 4½ feet

and remained stable during the pumping period. We are working closely with the North Dakota Water Commission to develop

a monitoring plan that will hopefully help us understand how to best utilize these types of wells in our area and elsewhere around

the state. Many areas have adequate water, but drilling and connecting multiple wells is prohibitively expensive or not possible.

The horizontal well system is another option to utilize water for beneficial purposes.

Starting point of the horizontal well installation

Midpoint of the well installation and completed well installation

Another major improvement at the site was the installation of a new lateral irrigator. The new system is equipped to apply

water with a variable-rate control system. This simply means if we have a plot that does not need water, for instance a dry edible

bean plot that is mature, and is beside a potato plot that still needs water, the nozzles will stop delivering water at the bean plot,

while nozzles remain operating on the potato plot. It also can put ¾ inch of water on one plot, and ½ inch on another. This system

will improve our quality of research and allow different types of investigations on water use. The new irrigation system will sustain

the basic needs on the project and offer many new opportunities well into the future.

We also acquired a new (used) Almaco plot combine which will serve us very nicely. The used machine has been outfitted

with a brand new automated weighing and grain moisture testing system to collect sample data as we harvest the plots. The combine

has a corn head and also a straight head that can be used for soybeans or small grain.

We would like to thank the North Dakota Corn Council, North Dakota Soybean Council, and the

North Dakota State Water Commission for partial financial support of these improvements.

Oakes Irrigation Research Site

Variety trials Crop index Home page Report 2015