IRRIGATON INSTALLATION DURING A DROUGHT
Tom Scherer, Extension Agricultural Engineer
It’s a natural reaction to want to save a crop that is “burning up” during a drought and it is tempting to try to install an irrigation system. As painful as it may be, the best advice for non-irrigators is often to wait things out during a drought. With the modern farm program and crop insurance, it may be more economical to let the crop go rather than try to save it by investing in irrigation. However, if you are determined to invest in irrigation, here are some things you need to know.
In North Dakota if you plan to irrigate more than five acres of land, a water permit is required. Field scale irrigation requires a large volume of water over the course of a growing season and a large flow rate. During drought conditions it is not uncommon to apply up to 14 inches of water per irrigated acre. This is about 380,000 gallons per acre. In addition, most field scale irrigation systems need a flow rate of at least 6 gallons per minute for each irrigated acre. For instance, if you want to irrigate 100 acres, a flow rate of 600 gallons per minute is needed to supply the average amount of water used by the crop on a daily basis.
Depending on your location and local water sources, obtaining a water permit can take up to a year and there is no guarantee that it will be granted. The current demand on the water source may prevent the State Water Commission from approving more permits for that particular water source. During a drought, surface water sources such as rivers and stream have lower flows and ponds or lakes can go dry. The demand for water increases and the competition for water can become very intense.
If you can find a water source and obtain a water permit, some irrigation equipment may be available on an emergency basis from dealers or area irrigators. During dry periods many irrigation dealers are very busy with existing irrigation systems and may not have the time to help develop temporary irrigation installations. In addition, the requirements on manpower, training, and financing to develop an irrigation system make it unrealistic as a short-term solution. Running an irrigation system can be a full-time job in itself.
Careful consideration is needed to assess whether a temporary or permanent irrigation system makes sense for you.
DO SOME RESEARCH
Important items to consider for a new irrigation system are the soil texture in the field, access to a water source, field layout, topography of the field, amount of management time and farm budget. The center pivot is the most common irrigation system used in North Dakota. There are several reasons why they are popular but the two most important are their low labor requirement and ease of operation. Center pivot controls have become very sophisticated. This makes them more valuable in terms of productivity, but also more of a commitment in terms of management and financial investment.
Collect information on the soil types in your fields. If you have a sandy soil with low water-holding capacity, an irrigation system can make a significant difference in crop yields. You can obtain soil survey information for your fields from the local USDA Natural Resource Conservation Service (NRCS) office, the online version called Web Soil Survey or your county Extension office. With the soils information, you can determine irrigation suitability. Soils in North Dakota are classified as either irrigable, non-irrigable or conditional. The first two classifications are self-evident but the majority of soils in North Dakota are considered conditional. This means that in some locations a particular soil series could be irrigated whereas in other locations the same soil series should not be irrigated. Conditional soils can be difficult to evaluate and therefore a registered soil classifier should be consulted. The local NRCS office can also provide help with problem soils.
What kind of pumping power is available? If available, electricity is generally the preferred power source. If power lines are nearby, it is the lowest cost source of power. Most electric irrigation pumps and equipment need three-phase, 480-volt power. Single-phase power can be used but phase conversion equipment or variable frequency motor controllers are required. Internal combustion engines (diesel is common) may be the most economical if your land is located a few miles from an existing power line. Early contact with your power supplier is necessary to allow time to plan and construct facilities.
Examine the types of crops you currently grow. During a drought the immediate concern is to save the current crop, however, irrigation is a significant investment and you need to consider future developments. You want to be sure that irrigation equipment costs will be offset by an increase in yields or quality of crop. You should consider the possibility of growing higher value crops (using irrigation) such as alfalfa, potatoes, dry beans, corn, soybeans and vegetables. Are they realistic for your soil type and climatic conditions? Generally, irrigating small grains is not economically viable.
Consider water sources. Contact the North Dakota State Water Commission (SWC), Water Appropriation Division, for water permit application information. They can also tell you about surface and groundwater sources in your area. Water information for your particular location can also be obtained online at the SWC's website (http://www.swc.state.nd.us/info_edu/map_data_resources/mapservices.html).The local county Extension and NRCS offices also have county groundwater maps that can show the location of suitable aquifers. Not all groundwater is suitable for irrigation. Often it is necessary to contact a well driller to drill test wells to determine the depth to the aquifer and get an estimate of the quantity of water that can be pumped. An approved lab should perform a soil/water compatibility analysis to ensure the water quality is suitable for irrigation and will not damage the soil.
Talk to irrigation equipment dealers about irrigation systems and what might be appropriate for your current or future needs. Irrigation dealers that have been in business for several years can be a valuable resource. They often have first-hand knowledge of the water resources, power availability and irrigation systems in your area. They can help you with problems caused by topography, slope, soils, field obstructions (tree belts, power poles, gullies, etc.), field size and piping to the water source.
Consider the economics of irrigation. Discuss potential yields with other area irrigators as well as your county Extension agricultural agent. During drought conditions, irrigation can double yields and pay for itself within 10 years. Yields of 150 to 180 bushels of corn, five tons or more of alfalfa and 2000 or more pounds of dry beans per acre are common under irrigation.
Assess your current economic conditions. Talk to your lenders. There are several loan programs available through the State Bank of North Dakota for new irrigation systems. Things to consider are the repayment schedules, interest rates and the effect on your farm financial picture. Investing in irrigation during a drought may not be a good idea because of the financial burden.
For more information, contact your local NDSU Extension county office. Other sources of irrigation information are the county NRCS office, the North Dakota State Water Commission and the Bank of North Dakota.
