Ohio is often described as a water-rich state. However, Ohio producers often find crop growth and yields limited by a shortage of soil moisture at critical times during the growing season. The Ohio Soil and Water Conservation Needs Inventory indicated that in 1966, Ohioans irrigated 32,000 acres of cropland. Estimates from the 1982 National Resources Inventory indicated that the irrigated area had increased only to about 33,100 acres, and a limited survey in 1989 suggested that less than 40,000 acres were irrigated that year. However, the droughts of 1988 and 1991 have raised many questions about water use and management. One area of interest is the use of supplemental irrigation for crop production.
This publication is intended to help you move in the right direction as you consider an investment in irrigation. First, ask yourself why you want to make this investment: Is it to reduce your risk of crop loss or failure because of insufficient water at critical times during the growing season? Is it to increase crop yields, or is it to provide protection against frost damage? Whatever your reason, only you can decide why you need to irrigate. After you have answered the question "why irrigate," then evaluate the following factors as they relate to your present or proposed crop-production system.
Eight major factors should be considered before you invest in an irrigation system. These are location, water supply, soil, drainage, crop, labor, management and system design.
Your location in the state will determine the amount, timing, type and distribution of precipitation. The annual precipitation in Ohio averages 38 inches statewide, but ranges from 42 inches on the southern border to about 32 to 34 inches along most of the northern border. Because of winds blowing over Lake Erie, the average annual precipitation reaches 44 inches in parts of northeastern Ohio, with a substantial proportion coming in the form of snow.
Long-term monthly rainfall information is important in determining the likely percentage of time that you may actually use supplemental irrigation during a given year, or over a period of years. Several sources of information are available to you. Locally, you may be able to obtain long-term monthly average rainfall records from a water pollution control center or municipal water treatment plant located in your county. If this source is not available, contact the Ohio Department of Natural Resources, Division of Water (Fountain Square, Columbus, OH 43224) for long-term monthly average rainfall information. Also,the Water Inventory Unit of the Division of Water publishes a Monthly Water Inventory Report for Ohio, which provides a monthly summary of the precipitation status in 11 major regions of the state. Write ODNR for more information. In addition to the above sources, the Ohio Agricultural Research and Development Center (OARDC), located in Wooster, Ohio, maintains long-term weather records. For information, contact the Statistics Laboratory, OARDC, Wooster, OH 44691.
Thoroughly investigate the location, quantity and quality of water that may be used for irrigation. Seek professional guidance. Generally, a well yield or stream flow of 6 to 15 gallons per minute will be required for each acre to be irrigated, depending on the crop and the soil at your location. However, for frost protection using irrigation, a flow rate of 45 to 65 gallons per minute per acre will be required. When using a farm pond for the water source, 1 to 1.5 acre feet of water should be stored for each acre to be irrigated.
Direct withdrawal of water from a stream is generally not a dependable source because streamflow may disappear during drought periods when irrigation water is needed most. However, if this source is an option for your application, consult with the Water Resources Development Section of ODNR Division of Water. In certain cases, a permit may be required to withdraw water from the Ohio portions of Lake Erie and the Ohio River watersheds. The Water Resources Development Section may also be able to provide information on other surface water sources in your area available for public or private use.
If you are considering drilling an irrigation well, consult the ODNR Division of Water for information about the availability of an adequate ground water supply. The Ground-Water Resources Section of the Division manages a statewide data base of more than 700,000 well logs. The Ground-Water Resources Section can provide you with an estimate of the size, geologic makeup and yield of aquifers in your area, and possibly furnish you with information about specific wells in the area.
In some cases, it may advisable to consult with a hydrogeologist or local well driller. Hydrogeologists may be listed in the telephone directory in the Yellow Pages. Also, the Division of Water at ODNR may be able to provide a list of hydrologists who provide consulting services in your area of the state. Another local source of information about wells in your area are professional well drillers. The Division of Water maintains a list of licensed well drillers (Ohio Directory of Drilling Contractors) and can provide you with a list of those operating in your area. You might consult the Yellow Pages for other information on well drilling.
When evaluating the water supply, the irrigator should be assured that the supply is adequate, of suitable quality and plentiful enough to meet the requirements of the acreage of crops to be irrigated. Also, the supply should be economically accessible and legally available. This last requirement has become increasingly important in recent years. If you have a facility, or combination of facilities, with the capacity to withdraw 100,000 gallons or more of water per day, then that facility must be registered with ODNR. This registration is required regardless of the water source (surface or ground water or a combination), unless the source is a municipality. An additional consideration related to the water supply is matching the pumping system with the yield of the water source (i.e., proper system design).
The soil should be capable of high production when treated with adequate amounts of crop nutrients and minerals, based on soil tests. Proper soil tilth, organic matter, weed control, and other proper soil and crop management practices are vitally important for successful irrigation.
Soils vary in their ability to hold water that the crop roots can use. Soil texture and organic matter are two soil properties that determine how much available water a given soil will hold, and the ease with which water can enter and move through the soil profile. Generally, water enters and moves through sandy soils very easily, but sandy soils do not have a great ability to hold water. Soils composed of a high percentage of fine silt and clay (medium and fine-textured soils) have a far greater ability to hold water compared to sandy soils, but water does not enter nor move through these soils as easily as through sandy soils. Crops grown on sandy soils generally respond better to irrigation than crops grown on medium and fine textured soils that have greater moisture holding capacities.
Your county USDA-SCS District Conservationist can provide you with details about the soils on your land, including information about the texture, water-holding ability, and other soil properties. In addition, the Research/Extension Analytic Laboratory (REAL) facility at OARDC in Wooster, can analyze soil samples for mineral and nutrient contents. Contact the REAL lab at (216) 263-3760 for information on soil testing and interpretation.
Good soil drainage is very important for successful irrigation, but is often neglected. Soil drainage relates to various soil properties including texture. Subsurface and/or surface drainage, as recommended in the Ohio Drainage Guide, should be installed before an irrigation system is purchased. Proper management of the soil water content is necessary to avoid crop damage from waterlogged soil.
Specific information about the drainage requirements for your soil can be obtained by contacting your District Conservationist. Another local source of drainage information may be professional drainage and/or soil and water conservation contractors.
Crop production and/or protection may be the number one reason why you are considering an investment in irrigation. Do you have a good estimate of the amount of water you need to grow a crop? The daily water-use requirements may range between 0.1 and 0.5 inches depending on the specific crop. How much of this amount can you expect to fill by natural rainfall? What is the seasonal distribution of rainfall in your location? These are important questions and you may need professional help to calculate the answers.
In most cases, irrigation in Ohio will be economically feasible with crops that give high returns per acre. These types of crops include strawberries, melons, nursery crops, potatoes, sweet corn, cucumbers, and most other vegetables. Irrigation of alfalfa may also be profitable for some Ohio dairy producers. The irrigation of seed corn might even be required as part of a contract for commercial seed production. Overhead sprinkler systems are the most commonly used type of system in Ohio, and trickle (or drip) irrigation systems have been used successfully for several years for many of Ohio's commercial horticultural crops and home gardens. However, irrigation of conventional corn and soybean production systems may not be economically feasible, particularly on soils with good water holding capacity, such as clay or clay loam soils. Also, remember to consider the effect of irrigation - increased yields - on your total crop production system. Can you handle the extra load? Is your infrastructure large enough to carry the increase in yields.
Frost protection is another reason you might irrigate. Sprinkler irrigation is very important for strawberries, blueberries, grapes and other fruit crops that may be damaged by spring frosts.
Generally, there are two types of irrigation systems used in Ohio: trickle (row crop tape, orchard emitter and micro-sprinkler, etc.) and overhead sprinkler (solid set, hand move, water winch, reel travelers and center pivots, etc.). Each specific type has different labor requirements. Studies have shown that about 1 human-hour per acre per day is required for a hand-moved irrigation system. Mechanically moved systems require only 10 percent to 50 percent as much labor. Labor requirements for drip/trickle systems are very low after the initial installation each year.
Ask yourself how much time and labor you can afford to put into running and managing an irrigation system. A reputable irrigation equipment supplier should be able to provide you with information on the labor requirements for specific types of systems.
Successful irrigation requires good planning and high-level management. Accurate decisions about the timing and amount of irrigation are very important and may make the difference between a successful and unsuccessful crop production year. Extra responsibilities associated with an irrigation system might include: monitoring the soil-moisture status in the field, scheduling the water application, simply making sure the water was turned on and off at the appropriate times, etc. How will the extra responsibility of irrigation management fit into your present crop production schedule?
By the time you get to the actual design process, you should have a very good idea of how your location and potential water supply might impact your decision. Also, you should now be aware of how conducive your soil and its drainage properties are to your selected crop under irrigated conditions. What kind of system will fit your production needs, and labor and management constraints? Profitable and efficient irrigation requires knowledge of all of the factors mentioned above and proper engineering of the entire system. For best results, each system should be "tailored" to fit the particular need.
Most irrigation equipment suppliers will provide the necessary engineering services and cost estimates, upon request. In addition, there are a number of consulting engineers who can provide the appropriate engineering services. Consult the Yellow Pages for irrigation equipment suppliers and consulting engineers in your area. Also, a neighboring farmer who has had experience with irrigation may be a good source of information regarding the selection of an irrigation equipment supplier.
This publication was intended to help you initiate a proper investigation of an irrigation system for your crop production system. The eight factors described above are only the beginning of your investigation into irrigation, but these are major items that you should consider before going further. Other items that should be considered include environmental aspects, financial resources, lease versus purchase, dealer availability and service, and the impact on your present production system. It pays to do your homework! For more information about irrigation in Ohio, contact your county Extension office, your county Soil and Water Conservation District, and/or any of the other informational sources mentioned above.
American Society of Civil Engineers. 1989. Evapotranspiration and Irrigation Requirements. ASCE.
Aull, G.H. 1980. Selecting Field Crop Irrigation System Components. AEIS No. 422. Cooperative Extension Service, Michigan State University, East Lansing, MI.
Brown, L.C. and L.P. Black. 1990. Surface and Ground Water Terminology. Fact Sheet No. AEX 460. Department of Agricultural Engineering, Ohio Cooperative Extension Service, The Ohio State University.
Burbank, W.E. 1975. Introduction to Irrigation ... A Checklist. Circular AE-92 (Revised). Cooperative Extension Service, North Dakota State University, Fargo, ND.
Hanson, J.R., A.F. Woldorf, and L.P. Black. 1990. Water Rights: An Overview of Ohio Water Withdrawal Law. ODNR Division of Water.
Hartstine, L.J. 1991. Hydrologic Atlas for Ohio: Average Annual Precipitation, Temperature, Streamflow, and Water Loss for the 50-Year Period 1931-1980. Water Inventory Report No. 28. ODNR Division of Water.
Hoffman, G.L, T.A. Howell and K.H. Solomon. (Eds.). 1990. Management of Farm Irrigation Systems. ASAE Monograph. American Society of Agricultural Engineers. St. Joseph, MI.
James, L.G. 1988. Principles of Farm Irrigation System Design. John Wiley and Sons.
Jensen, M.E. (Editor). 1983. Design and Operation of Farm Irrigation Systems. (revised printing). ASAE Monograph No. 3. American Society of Agricultural Engineers. St. Joseph, MI.
Ohio Department of Natural Resources. 1990. Water Withdrawals in Ohio: An Overview of Ohio's Water Withdrawal Facility Registration Program. ODNR Division of Water.
Palmer, M.L. and E.C. Wittmeyer. 1982. Sprinkler Irrigation in Ohio: Some Basic Considerations. Cooperative Extension Service, The Ohio State University, Columbus, OH.
Robbins, P.R., E.E. Carson, R.Z. Wheaton, and J.V. Mannering. (Undated). Irrigation of Field Crops in Indiana, A Guide for Evaluating Irrigation Potential on Your Farm. ID-119. Cooperative Extension Service, Purdue University, West Lafayette, IN.
Ross, D.A. 1987. Information Needed for Irrigation System Planning. FACTS 156 (Revised). Cooperative Extension Service, The University of Maryland, College Park, MD.
Schwab, G.O., R.K. Frevert, T.W. Edminster, and K.K. Barnes. 1981. Soil and Water Conservation Engineering. 3rd Edition. John Wiley and Sons.
Thomas, J.G. 1988. Irrigation System Selection. Publication 1508. Cooperative Extension Service, Mississippi State University, Starkville, MS.
USDA-SCS. 1970. Ohio Irrigation Guide. (Out-of-print; Copy on file at each county SCS office).
USDA-SCS. 1973. Ohio Drainage Guide. (Out-of-print; Copy on file at each county SCS office).
The authors thank the following for their review of this publication: Melville Palmer, Professor Emeritus and former Extension Agricultural Engineer, The Ohio State University; Mark Ackerman, George F. Ackerman Co., Curtice, OH; Robert D. Webb, Columbus Irrigation Co.,Inc., Columbus, OH; Leonard P. Black, Water Planner, ODNR Division of Water, Columbus, OH; and Art Brate, State Conservation Engineer, USDA-SCS, Columbus, OH.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
TDD No. 800-589-8292 (Ohio only) or 614-292-1868