When planning a new irrigation system for your farm, a little organization can help avoid mistakes. Lyndon Kelley, Extension irrigation educator for Indiana and Michigan, developed this list of irrigation FAQs.
Q. Is water available in the quantities needed to irrigate?
A. In Indiana and Michigan, evaporation and plant water use from the soil are between one-fourth and three-tenths of an inch for several days each summer; systems that can provide 5 gallons per acre irrigated will meet the one-fourth inch minimum per day. Seven gallons per acre irrigated is needed to provide the three-tenths inch water requirement. This capacity will be required for 24/7 continued pumping in a time of drought.
Q. How do I determine if I have sufficient groundwater resources?
A. Irrigation is not profitable without a reliable and adequate source of water. Nearby large-volume irrigation, or municipal or industrial wells are excellent sources of water. Well-drillers familiar with large-volume wells in your area are also good resources. Indiana information on groundwater availability is located on the state’s Department of Natural Resources website. Michigan’s groundwater mapping tools can help evaluate potential water withdrawal sites.
Q. Is surface water available in dependably large volumes?
A. Surface water quantities need to be available at the time of maximum irrigation, often from late July to early August. This is when surface waters are near their lowest levels. Make sure to evaluate available flow the summer before you start irrigating. In most areas, you may not deplete stream flow to the extent that it negatively impacts neighbors or the environment. Remember, there can be major contamination challenges affecting food safety and plant disease when using surface water for vegetable irrigation and cooling.
Q. Do I have to follow regulations on water rights?
A. Make sure you understand your rights and obligation to use water in your state. Information on Indiana water rights is available from the Indiana Department of Natural Resources. For information on Michigan water rights, consult Extension publication, Legal Aspects of Irrigation Water Use in Michigan.
Q. Do I need a permit to install a large-volume well?
A. Irrigation is nearly always considered large-volume water use (capacity to pump more than 70 gallons per minute). New installations require registration in both Indiana and Michigan. In Indiana, this is handled by the Indiana Department of Natural Resources. Permitting of large-volume water withdrawals may also be required within the Great Lakes Basin in Indiana. In Michigan, use the Michigan Water Withdrawal Assessment Tool to determine if your proposed water use is likely to cause a negative environmental impact. For information on Michigan’s water-use registration process, see MSU Extension publication, "Michigan Large Volume Water Use Requirements."
Q. Can I share irrigation equipment with my neighbor?
A. Irrigation systems are very scale dependent. Sharing the irrigation expense by jointly investing with a neighbor often leads to a better and more cost-effective configuration. For more information on split irrigation cost between neighbors, see MSU/Purdue Extension publication, "Shared Irrigation Expenses."
Q. How can I make an effective irrigation plan?
A. Acquire an aerial map of all the land in question for your irrigation projects. Excellent maps and tools are available from Google maps and others, or your local USDA Farm Service Agency paper map and a pencil/compass will work. Identify large expanses of land that you have available, that are adjacent to your land or that you may share the water sources. Identify major excavation needs such as woodlot or fence line removal. Identify drainage ditch and wet areas that will require modifications for the system to cross.
Identify available power sources—a three-phase power line in close proximity (one-half mile or less) to potential water source(s) is the cheapest. Liquid fuel storages located near wells and surface water pose potential environmental risks and have higher equipment, maintenance and fuel costs. Engine power is a second choice for most situations.
Use irrigation professionals to your advantage. Take your best ideas to at least two irrigation sales/design representatives. Many will have access to excellent mapping and planning software tools, plus they will have far more experience than most producers in irrigation system design. Compare potential designs on a cost-per-irrigated-acre basis (for an average year’s irrigation). This will help equalize investment in equipment with energy cost and labor. Example worksheets are available under Irrigation Costs.
Q. How can I determine if irrigation is economically feasible?
A. Make sure irrigation will pay. Think in terms of increasing your average net income per acre, after you have covered the additional irrigation-related bills. To receive positive outcomes, expect to provide good estimates of increased fixed and variable costs. Figuring this amount out in advance of the investment is detailed, but well worth the time. An excellent tool to assist in evaluating the economic feasibility of a proposed project is the Capital Investment model (located under the Irrigation Costs section) developed by MSU Extension educator Roger Betz.
Q. What crops benefit the most from irrigation?
A. Among traditional crops, commercial corn and alfalfa have shown the greatest economic advantage from irrigation. Small grains and soybeans have offered some of the lowest returns from added investment in irrigation. Changes in crop rotations often result from adding irrigation. Although it is not always the case, a smaller proportion of irrigated fields are managed using no-till systems than non-irrigated fields. Excessive corn residue produced on irrigated fields might be part of the reason.
Indiana and Michigan’s irrigated land is dominated by contracted, specialty crops such as vegetable and hybrid seed corn production. The reduced risks offered by sandy soils for early planting, fewer delays after rain for field work and low to no flooding injury potential, coupled with the removal of drought stress, entice the high-dollar invested seed and vegetable crops to the area. These options and conditions are not available everywhere in Michigan and Indiana.
Do your homework, and identify what options are realistically available and feasible for your operation. For more information on irrigation design and management information, visit Lyndon Kelley’s irrigation website.