Context: The irrigation application rate will vary throughout the length of a center pivot irrigation system, with the highest instantaneous application rate at the end of the system furthest from the pivot point. Irrigation application rate will be uniform for solid set and large gun hose traveler irrigation systems as long as application time or forward travel of system is unchanged.

Question: How will the irrigation application rate vary throughout the length of a center pivot irrigation system?

Answer: the highest instantaneous application rate at the end of the system furthest from the pivot point

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Context: Option to purchase the farm in future: (c) Repayment requirements of the unrecouped portion of the permanent land improvements made by the lessee if contract is prematurely terminated is often view as a form of security from farm land being sold out from their ability to lease. A schedule of repayment is constructed by amortizing the dollar investment over the period of the contract at the current interest rate. The resulting chart allows the landowner to find the agreed upon fee for early termination of the contract. Contract needs to have provisions for early termination upon one of agreed list if situations happen. These may include death of one of the parties, sale of farm or dissolving of the farm business.

Question: what does the repayment schedule chart allow for?

Answer: allows the landowner to find the agreed upon fee for early termination of the contract

Specht, J., & Torrion, J. (2015). Optimize Your Irrigation Application Timing with SoyWater.unl.edu | CropWatch | University of Nebraska–Lincoln. https://cropwatch.unl.edu/optimize-your-irrigation-application-timing-soywaterunledu


Context: (4) SoyWater: an easy to use, irrigation management tool from The University of Nebraska- Lincoln (UNL). The tool is well recognized for its crop development model that helps producer predict when the soybean plant is at a development stage and when irrigation is needed. The online program retrieves data from the USDA soil surveys for the field being irrigated and has been adapted for use in Michigan allowing it to pull in needed daily weather information from the Enviroweather weather network.

Question: what is a state the Soywater has been adapted for use in?

Answer: Michigan

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: Calculating the amount to raise the rent if the landowner invests in the well and other permanent land improvements is a common question. In most situations the landowner wants to get more for the investment in the well then annual estimated cost of the investment in the well (DIRTI formula). Calculation of the annual cost of ownership of an investment is often represented by the DIRTI (Depreciation, Interest, Repairs, Taxes, and Insurance) formula which spreads the actual cost of ownership of an equipment investment over its usable lifespan or investment period. A standard procedure is outlined on page 7 of MSU Extension Bulletin E-2131, "Custom Work Rates in Michigan". This formula will provide you with the annual cost of the original investment in equipment and improvements

Question: what is a goal of investing in the well and other permanent land improvements?

Answer: to get more for the investment in the well then annual estimated cost of the investment in the well (DIRTI formula)

Kelley, L. (2009c). Irrigation Fact Sheet #9 - Michigan Large Volume Water Use Requirements. https://www.canr.msu.edu/uploads/235/67987/lyndon/9largewaterwith.pdf


Context: (3) On and after July 9, 2009 ' Large quantity water withdrawals proposed after July 8, 2009 must receive a favorable assessment from 'Michigan's Water Withdrawal Assessment Tool' or an approval from a requested site-specific review by the MDEQ and be registered before proceeding. If a site-specific review by the MDEQ or an evaluation by the Water Withdrawal Assessment Tool determines that a proposed withdrawal is a zone A or a zone B withdrawal, there is a rebuttable presumption that the withdrawal, as specified in the review or tool, will not cause an adverse resource impact. As previously stated penalties are in place for causing an adverse resource impact.

Question: what are in place for causing an adverse resource impact?

Answer: penalties

Kelley, L. (2007b). Irrigation Fact Sheet #4 - Michigan Registration for New Agricultural Withdrawals. https://www.canr.msu.edu/uploads/235/67987/lyndon/MIRegNewAgWith.pdf


Context: Baseline Capacity (Rated Capacity): The registration process establishes a "Baseline Capacity" based on the available withdrawal capacity of a system. The baseline capacity of the system should be reported as pump capacity in gal/min. along with a pump and system description which is compatible with the well log. Baseline capacity applies to both wells and surface water withdrawals. Please note: You should report this baseline capacity value on the registration form on the line listed as "Rated Capacity".

Question: what unit should the baseline capacity of the system be reported in for the registration process?

Answer: gal/min

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: Both acts use the same definition for a "large capacity well". Large capacity wells are those with the capacity to withdraw 100000 gallons per day (70 gal/min) on average in any consecutive 30-day period. The combined capacity of more than one well at a site that is 100000 gallons or greater capacity/day (70 gal/min), also meets the large capacity well definition. Water use reporting also includes surface water withdrawals with single or combined capacity at a site of 100000 gal/day (70 gal/min) on average, in any consecutive 30-day period. All agricultural water uses (irrigation, cooling, animal watering, etc.) will apply to these laws. Well pumping capacity is included in the well log that should have been filed if the well was drilled after 1968 and are generally available at the local health department, from well drillers or at the MDEQ website.

Question: What agricultural water uses apply to these laws (P177 and P148)?

Answer: All

Kelley, L. (2013a). Efficient irrigation application volumes change throughout crop development. https://www.canr.msu.edu/news/efficient_irrigation_application_volumes_change_throughout_crop_development


Context: The irrigated sandy loam soils of northern Indiana and southern Michigan require about half an inch of irrigation to wet the soil profile down five to six inches. A single half inch application is often enough to germinate seed, assist in emergence (alleviate crusting) and incorporate fertilizers and pre-emergence herbicides. Heavier loam soils may need 0.7 inch to 1 inch of water to wet the top 6 inches of soil to accomplish these tasks.

Question: what amount of irrigation application is often enough to germinate seeds in northern Indiana and southern Michigan?

Answer: A single half inch application

Kelley, L. (2013a). Efficient irrigation application volumes change throughout crop development. https://www.canr.msu.edu/news/efficient_irrigation_application_volumes_change_throughout_crop_development


Context: Maximum economic yield with minimum amount of irrigation is a goal for most irrigators. Efficient irrigation water use means providing enough water to avoid drought stress, but not so much that water is lost out of the rooting zone or to runoff from the surface. This includes leaving enough water holding capacity to capture the next normal rainfall thus not losing the value of rainfall and also reduce the risk of leaching and run-off. In the irrigated region of northern Indiana and Michigan evaporate losses during irrigation application are minimal due to high humidity. The humid condition cause several differences in irrigation management for efficiency compared to the arid west.

Question: what contributes to efficient irrigation water use?

Answer: leaving enough water holding capacity to capture the next normal rainfall thus not losing the value of rainfall and also reduce the risk of leaching and run-off

Kelley, L. (2022). Irrigation Fact Sheet #11- Checklist for Planning Irrigation Systems. https://www.canr.msu.edu/irrigation/upoads/files/11ChecklistForPlanningIrrigationSystems08.22.pdf


Context: (10) Irrigation economics. 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 good outcomes, expect to provide good estimates of increased fixed and variable costs. Figuring this out in advance of the investment is detailed, but is well worth the time. An excellent tool to assist in evaluating the economic feasibility of a proposed project is the "Capital Investment Model" developed by MSU Educator xxxxx xxxx.

Question: what is an excellent tool to assist in evaluating the economic feasibility of a proposed irrigation project?

Answer: Capital Investment Model

Kelley, L. (2010). Irrigation Fact Sheet #10 - Shared Irrigation Expenses. https://www.canr.msu.edu/uploads/235/67987/lyndon/10_Shared_Irrigation.pdf


Context: Finding a fair cost for shared irrigation systems: If you can find the true annual cost of an irrigation system it is easy to prorate the annual cost of the investment and annual power and labor cost by the number of acres the system provides for each party.

Question: what does finding the true annual cost of an irrigation system make it easier to do?

Answer: to prorate the annual cost of the investment and annual power and labor cost by the number of acres the system provides for each party

Kelley, L. (2013). Irrigation Fact Sheet #12 - Nitrogen Application with Irrigation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/12_NitrogenApplicationWithIrrigationFact_Sheet.pdf


Context: Irrigated production has the advantage of fertigation as an option in nitrogen management. Fertigation is the process of applying fertilizer through irrigation water. Liquid 28% nitrogen is the most common product for fertigation, but urea and micro-nutrient solutions are also available to meet crop nutrient needs, with proper equipment.

Question: what is an option for nitrogen management in irrigated production?

Answer: fertigation

Kelley, L. (2014). Irrigation Fact Sheet #7- Reducing and Evaluating Irrigation Runoff.Instantaneous irrigation application rates compared to soil infiltration rates. https://www.canr.msu.edu/uploads/235/67987/FactSheets/7_ReducingAndEvalRunoff.pdf


Context: Determining the irrigation application rate is part of the planning process for new irrigation systems. It is measured by the average irrigation application rate from a particular point along the machine and is expressed as inches per hour. To determine application rate divide the amount of water applied by the elapsed time (from the first drop of water landing at a point in the field to the last drop hitting the point).

Question: what is determining the irrigation application rate a key part of?

Answer: the planning process for new irrigation systems

Kelley, L. (2014b). Irrigation Fact Sheet #13 - Reducing and Evaluating Irrigation Runoff. https://www.canr.msu.edu/uploads/236/43605/FactSheets/13_ReducingAndEvaluatingIrrigationRunoff_5-9-14.pdf


Context: The infiltration rate is the rate water can enter the soil surface. Michigan soils have infiltration rates from a high of 1 inch/2 hour to, as little as 20 minutes per inch. Heavier soils such as clay and clay loam will take water in at a slower rate than sands and sandy loams. Tillage method and surface compaction since a tillage operation affects infiltration rate. Conservation tillage and no-till result in the highest infiltration rate while disc and moldboard tillage result in the lowest rates, particularly after several wetting events. Estimates for water infiltration rates are included in the "physical and chemical properties of soils" section of the soil survey for your county.

Question: what tillage operations result in the highest soil infiltration rates?

Answer: Conservation tillage and no-till

Kelley, L. (2022). Irrigation Fact Sheet #11- Checklist for Planning Irrigation Systems. https://www.canr.msu.edu/irrigation/upoads/files/11ChecklistForPlanningIrrigationSystems08.22.pdf


Question: when should an irrigator determine increases in fixed and variable costs of a system to receive good estimates for the economics of an irrigation system?

Answer: in advance

Kelley, L. (2014). Irrigation Fact Sheet #7- Reducing and Evaluating Irrigation Runoff.Instantaneous irrigation application rates compared to soil infiltration rates. https://www.canr.msu.edu/uploads/235/67987/FactSheets/7_ReducingAndEvalRunoff.pdf


Context: Infiltration rate is the quantity of water that can enter the soil in a specified time interval. Heavier soils such as clay and clay loam take water in at a slower rate than sands and sandy loams. Tillage method and surface compaction affect infiltration rate. Conservation tillage and no-till result in the highest infiltration rates while disc and moldboard tillage result in the lowest rates, particularly after several wetting events. Michigan soils have infiltration rates from as slow as one-half inch per hour to as fast as three inches per hour. Estimates for water infiltration rates are included in the Physical and Chemical Properties of Soils section of the soil survey for each county.

Question: what is one affect that tillage methods and surface compaction can have?

Answer: infiltration rate

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Context: Sub-leasing: One major issue that needs to be considered in the negotiations of adding irrigation is the ability for the lessee to sublet the property. As high dollar specialty crop become more common in the area opportunity to rent irrigated land for a single production year for nearly double the local irrigated rent rate become a reality. Annual sub-renting could leave land owners with an unfamiliar face to deal with if neighbor water well issue arises. Addressing sub-leasing issue in writing can avoid grief and confusion in the future.

Question: what is one negative impact of annual sub-renting with regard to the lessee and land owner?

Answer: Annual sub-renting could leave land owners with an unfamiliar face to deal with if neighbor water well issue arises

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Context: Checkbook method of irrigation scheduling follows the concept that the soil in your field is like a bank checking account. Rainfall and irrigation applications are deposits into the checking account. Rainfall and irrigation may need to be reduced to reflect the effective amount added to soil moisture. Daily water removal from evaporation and transpiration (evapotranspiration or E.T.) from the field and crop would be considered withdrawals from the account. Soil has a maximum amount of water that can be held (called Field Capacity), so water added beyond the soils water holding capacity is lost to the account. Irrigation applied at a rate exceeding the infiltration capacity will cause surface runoff and be lost to the soil water balance account.

Question: what will irrigation applied at a rate exceeding the infiltration capacity cause?

Answer: surface runoff

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Context: Permanent land improvement associated with the addition of irrigation to the property would often include: (a) land clearing cost (b) well casing (c) pump/motor (d) electrical panel (e) back-flow preventer (f) z-pipe (g) field risers (h) pivot pads or anchors

Question: what does permanent land improvement associated with the addition of irrigation to the property often include?

Answer: (a) land clearing cost (b) well casing (c) pump/motor (d) electrical panel (e) back-flow preventer (f) z-pipe (g) field risers (h) pivot pads or anchors

Kelley, L. (2011). New irrigation planning checklist - MSU Extension. https://www.canr.msu.edu/news/new_irrigation_planning_checklist


Context: (9) Get multiple bids. Use irrigation professionals to your advantage. Take your best ideas to at least two irrigation sales/design people. 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 years irrigation). This process will help equalize investment in equipment with energy cost and labor.

Question: what will irrigation sales/design people help provide you with?

Answer: far more experience than most producers in irrigation system design

Kelley, L. (2014a). Irrigation Fact Sheet #7- Reducing and Evaluating Irrigation Runoff.Instantaneous irrigation application rates compared to soil infiltration rates. https://www.canr.msu.edu/uploads/235/67987/FactSheets/7_ReducingAndEvalRunoff.pdf


Context: Increasing the amount of water that may enter the soil in a given period of time: The instantaneous irrigation application rate will vary throughout the length of a center pivot irrigation system, with the highest instantaneous application rates at the end of the system furthest from the pivot point. Instantaneous irrigation application rate will be uniform for solid set and large gun hose traveler irrigation systems as long as application time or forward travel of system is unchanged.

Question: to have a uniform instantaneous irrigation application rate for solid set irrigation systems what condition must be met?

Answer: application time or forward travel of system is unchanged.

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: Act PA 148 established state-wide groundwater mapping and water use reporting. This law created a groundwater resource map of the state and establishes a groundwater advisory committee to direct groundwater protection efforts in the future. The MDA will assemble township-based reports annually and forward them to the MDEQ.

Question: How often are township-based water reports assembled?

Answer: annually

Kelley, L. (2009c). Irrigation Fact Sheet #9 - Michigan Large Volume Water Use Requirements. https://www.canr.msu.edu/uploads/235/67987/lyndon/9largewaterwith.pdf


Context: (1a) Existing on February 28, 2006 ' Subject to water use reporting. These withdrawals from either wells or surface water are exempt from the new adverse resource impact standards. This is often termed as "Grandfathering", but these withdrawals may still be required to share the water resource with both other "grandfathered" users and with all new users since the legislation still hold Michigan's water use as a riparian right.

Question: what are withdrawals from either wells or surface water existing on February 28, 2006 exempt from?

Answer: the new adverse resource impact standards

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: Pump capacity multiplied by run time or fuel/power use/hr: Many pumping systems are equipped with hour meters or run time timers. With an accurate estimate of pumping a producer can calculate water use.

Question: with an accurate estimate of pumping water can a producer calculate?

Answer: water use

Kelley, L. (2022). Irrigation Fact Sheet #11- Checklist for Planning Irrigation Systems. https://www.canr.msu.edu/irrigation/upoads/files/11ChecklistForPlanningIrrigationSystems08.22.pdf


Context: (8) Power sources. Identify available power sources - a 3 phase power line in close proximity (1/2 mile or less) to potential water sources is the cheapest. Liquid fuel storages located near wells and surface water pose potential environmental risks, along with higher equipment, maintenance and fuel cost, leaving engine power as a second choice for most situations.

Question: what pose as potential environmental risks, and typically increase equipment, maintenance, and fuel costs?

Answer: Liquid fuel storages located near wells and surface water

Kelley, L. (2010). Irrigation Fact Sheet #10 - Shared Irrigation Expenses. https://www.canr.msu.edu/uploads/235/67987/lyndon/10_Shared_Irrigation.pdf


Context: Annual operating costs will include an estimate of energy cost and labor attributable to the average operation of the equipment. For calculation purposes an annual use of six 1 inch applications of irrigation was used. A greater number of small applications will favor systems that have low labor costs, where a smaller number of large applications would favor systems with high labor and low investment attributes. Systems with low energy cost primarily from low pumping cost are favored by higher total annual use where low initial cost often compensate for higher energy cost if a low total volume of water is applied annually.

Question: what can compensate for higher energy cost if a low total volume of water is applied annually.

Answer: low initial cost

Kelley, L. (2014a). Irrigation Fact Sheet #7- Reducing and Evaluating Irrigation Runoff.Instantaneous irrigation application rates compared to soil infiltration rates. https://www.canr.msu.edu/uploads/235/67987/FactSheets/7_ReducingAndEvalRunoff.pdf


Context: Infiltration rate decreases with increased wetting time. Therefore, the amount of water applied during each application affects the fraction of water that enters the soil and the fraction of runoff. Small pockets and depressions in the soil surface hold a volume of water at that location until the soil surface receives the water. Midseason cultivation or in-row soil surface modification (i.e. dammer/diker) increases the surface storage.

Question: what affects the amount of water that is absorbed by the soil and the amount of water that becomes runoff?

Answer: the amount of water applied during each application

Kelley, L. (2014b). Irrigation Fact Sheet #13 - Reducing and Evaluating Irrigation Runoff. https://www.canr.msu.edu/uploads/236/43605/FactSheets/13_ReducingAndEvaluatingIrrigationRunoff_5-9-14.pdf


Context: Increasing the amount of water that may enter the soil in a given period of time: Residue cover and a rough soil surface will increase the infiltration rate. Compaction of the soil surface, lack of residue and poor choice of tillage practice will decrease infiltration. Steeper slopes, wheel tracks, and rows run up and down hillsides increase runoff rates if the water dies not infiltrate. Infiltration rate decreases with increased time of wetting. Therefore, the amount of water applied each irrigation will affect the fraction of the water that enters the soil and the fraction that will runoff. Small pockets and depres- sions in the soil surface will hold a volume of water at that location, until the soil surface can receive the water. Midseason cultivation or in-row soil surface modification (i.e. dammer/diker) will increase the surface storage.

Question: what will affect the amount of water that is infiltrated and the amount of water that becomes runoff?

Answer: the amount of water applied each irrigation

Kelley, L. (2013). Last chance nitrogen application with irrigation - MSU Extension. https://www.canr.msu.edu/news/last_chance_nitrogen_application_with_irrigation


Context: Fertigation is often the last step in a three split nitrogen management plan, following starter and side dress applications. Starter allows quick access to nutrients to the newly germinated plants. Side dress applications usually account for the greatest portion of N budget, feeding the plant just prior to the rapid growth phase. Depending upon the equipment used, side-dressing can also aerate soil and improve water infiltration. Fertigation makes up the remainder of the budget supplying nitrogen to the crop just prior to tassel emergence. For efficient use, Nitrogen applications need to be made prior to tasseling to ensure that the nitrogen applied is in an available form for the plant to uptake and use during early grain formation.

Question: what is often the last step when following a three split nitrogen management plan?

Answer: Fertigation

Kelley, L. (2011). New irrigation planning checklist - MSU Extension. https://www.canr.msu.edu/news/new_irrigation_planning_checklist


Context: (3) Surface water availability. Is surface water available in dependable large volumes? Surface water quantities need to be available at the time of maximum irrigation, often late July early August. This is the season the surface waters are near their lowest. Make sure to evaluate available flow the summer before you start irrigating. In most areas you may not delete stream flow to the extent that it negatively impacts neighbors or the environment. If not, consider part of the water of the States, drainage ditches flow, may be depleted. Remember there can be major contamination challenges impacting food safety in using surface water for vegetable irrigation and cooling.

Question: when do surface water quantities need to be available?

Answer: at the time of maximum irrigation, often late July early August

Kelley, L. (2014b). Irrigation Fact Sheet #14  - Irrigation Application Volumes. https://www.canr.msu.edu/uploads/235/67987/FactSheets/14_IrrigationApplication.pdf


Context: Early in the season our irrigation goals are often focused on germinating seed and incorporating fertilizers or pre-emergent herbicides. In a normal year, May and early June often receive adequate rainfall to meet the needs of the developing crops and plant roots will grow into moisture that is stored deeper in the soil profile. Chances of receiving additional rainfall in the near future are rather good, so irrigation applications are kept to a minimum with the hope that nature will be providing more water soon. Roots that are not fully established leave only a limited soil water holding capacity capable making small application ideal.

Question: during may and early june how is the irrigation application typically affected?

Answer: irrigation applications are kept to a minimum with the hope that nature will be providing more water soon

MSU Extension. (2024). Irrigation Costs - Irrigation. https://www.canr.msu.edu/irrigation/Irrigation-Planning-/irrigation-costs


Context: In extreme situations of average daily temperatures over 90 degrees, low relative humidity and wind, water use may reach .31 to .33 inches per day. Crops that cannot tolerate extremes may need an irrigation system designed to meet a requirement of one inch every 3 days (6.5 gallons/minute/acre of irrigation). System design capacity of greater than 6.5 gallons/minute/acre of irrigation are only needed in situation where crop management practice result in water application at a rate faster than the soil infiltration rate resulting in water loss below the root zone or less than 100% effective water use.

Question: what type of irrigation system may need to be installed for crops susceptible to extremes?

Answer: an irrigation system designed to meet a requirement of one inch every 3 days (6.5 gallons/minute/acre of irrigation)

Kelley, L. (2007b). Irrigation Fact Sheet #5 - Estimating Annual Irrigation Costs. https://www.canr.msu.edu/uploads/235/67987/irrigation_costs/5_Estimating_Annual_Irrigation_Costs.pdf


Context: Annual operating cost will include an estimate of energy cost and labor attributable to the average operation of the equipment. For calculation purposes an annual use of six one inch applications of irrigation was used. A greater number of small applications will favor systems that have low labor costs, where a smaller number of large applications would favor system with high labor and low investment attributes. Systems with low energy cost primarily from low pumping cost are favored by higher total annual use where low initial cost often compensate for higher energy cost if a low total volume of water is applied annually.

Question: what labor system does a greater number of small irrigation applications favor?

Answer: systems that have low labor costs

Kelley, L., & Miller, S. (2019). Irrigation Fact Sheet #3 - Irrigation Scheduling Tools. https://www.canr.msu.edu/uploads/236/43605/FactSheets/3_IrrigationSchedulingTools5.14.pdf


Context: (3) MSU Excel Version of Scheduler: allows greater flexibility and adaptability to irrigators who are comfortable using Excel. This method will provide results for all of Michigan and the upper tier counties in Indiana. Reference crop E.T. can be taken from each of the Enviro-weather stations where the program will use crop specific coefficient to adjust for your crop stage of growth.

Question: where will reference crop evapotranspiration data be obtained from?

Answer: each of the Enviro-weather stations

Kelley, L. (2014b). Irrigation Fact Sheet #13 - Reducing and Evaluating Irrigation Runoff. https://www.canr.msu.edu/uploads/236/43605/FactSheets/13_ReducingAndEvaluatingIrrigationRunoff_5-9-14.pdf


Context: Instructions for completing the Evaluating Potential Irrigation Runoff form. 1. Identify the areas of the irrigated field that have the lowest infiltration rates and/or greatest runoff potential. (heavy soils, slopes, surface compaction). 2. Select a radial transect line (for center pivots) or a transect line representing the watering pattern (for solid set or traveler systems) through the identified lowest infiltration/highest runoff potential area of the field identified above.

Question: what are the first two instructions for completing the Evaluating Potential Irrigation Runoff form?

Answer: 1. Identify the areas of the irrigated field that have the lowest infiltration rates and/or greatest runoff potential. (heavy soils, slopes, surface compaction). 2. Select a radial transect line (for center pivots) or a transect line representing the watering pattern (for solid set or traveler systems) through the identified lowest infiltration/highest runoff potential area of the field identified above

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: Flow meters are mechanisms installed in or on the main distribution pipe of the water supply. The actual flow is measured by impeller or sonar. Flow meters have the advantage of simplicity as meters and can be read monthly and recorded. The disadvantage to flow meters is cost and maintenance. To maintain accuracy meters need to be calibrated at least annually. Meters need to be installed in a straight section of pipe at a point in the transport pipe where all of the water used must pass.

Question: how is actual flow measured with flow meters?

Answer: impeller or sonar

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Context: Checkbook method of irrigation scheduling follows the concept that the soil in your field is like a bank checking account. Rainfall and irrigation applications are deposits into the checking account. Rainfall and irrigation may need to be reduced to reflect the effective amount added to soil moisture. Daily water removal from evaporation and transpiration (evapotranspiration or E.T.) from the field and crop would be considered withdrawals from the account. Soil has a maximum amount of water that can be held (called Field Capacity), so water added beyond the soils water holding capacity is lost to the account. Irrigation applied at a rate exceeding the infiltration capacity will cause surface runoff and be lost to the soil water balance account.

Question: what are evaporation and transpiration commonly referred to as?

Answer: evapotranspiration or E.T.

Kelley, L. (2007). Irrigation Fact Sheet #4 - Michigan Registration for New Agricultural Withdrawals. https://www.canr.msu.edu/uploads/235/67987/lyndon/MIRegNewAgWith.pdf


Context: New wells and surface water withdrawals in Michigan, installed after February, 2006, that are capable of pumping 100000 gallon per day (70 gpm) are now required to register with Michigan Department of Agriculture prior to beginning to pump. All water withdrawals that reported prior to 2006 are considered properly registered. Forms are available directly from the MDA website or from the St. Joseph County MSU Extension website then navigate to link for irrigation on the left hand side.

Question: what types of pumping systems are required to register with the Michigan Department of Agriculture (MDA) prior to beginning to pump?

Answer: New wells and surface water withdrawals in Michigan, installed after February, 2006, that are capable of pumping 100000 gallon per day (70 gpm)

Kelley, L. (2013). Last chance nitrogen application with irrigation - MSU Extension. https://www.canr.msu.edu/news/last_chance_nitrogen_application_with_irrigation


Question: what step in the three split nitrogen management plan allows for quick access to nutrients to the newly germinated plants?

Answer: Starter

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: Calculating the amount to raise the rent if the landowner invests in the well and other permanent land improvements is a common question. In most situations the landowner wants to get more for the investment in the well then annual estimated cost of the investment in the well (DIRTI formula). Calculation of the annual cost of ownership of an investment is often represented by the DIRTI (Depreciation, Interest, Repairs, Taxes, and Insurance) formula which spreads the actual cost of ownership of an equipment investment over its usable lifespan or investment period. A standard procedure is outlined on page 7 of MSU Extension Bulletin E-2131, "Custom Work Rates in Michigan". This formula will provide you with the annual cost of the original investment in equipment and improvements

Question: what does the DIRTI formula represent?

Answer: spreads the actual cost of ownership of an equipment investment over its usable lifespan or investment period

Kelley, L. (2007a). Irrigation Fact Sheet # 2 - Irrigation Application Instantaneous Rates. https://www.canr.msu.edu/uploads/235/67987/FactSheets/2_IrrigationApplicationRates1.30.pdf


Context: The irrigation application rate will vary throughout the length of a center pivot irrigation system, with the highest instantaneous application rate at the end of the system furthest from the pivot point. Irrigation application rate will be uniform for solid set and large gun hose traveler irrigation systems as long as application time or forward travel of system is unchanged.

Question: as long as application time or forward travel of system is unchanged how will irrigation application rate vary for solid set or large gun hose traveler systems?

Answer: Irrigation application rate will be uniform

Kelley, L. (2011). New irrigation planning checklist - MSU Extension. https://www.canr.msu.edu/news/new_irrigation_planning_checklist


Context: (12) Specialty/vegetable crop options. Indiana and Michigan's irrigated land is dominated by contracted specialty crops like vegetable and hybrid seed corn production. The reduced risks offered by sandy soils for early planting, less delays after rain for field work, 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. Avoid the idea that "if you build it they will come". Do your homework and identify what options are realistically available and feasible for your operation.

Question: what ideology should be avoided when growing crops in Michigan and Indiana?

Answer: "if you build it they will come"

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Context: Option to purchase the farm in future: (c) Repayment requirements of the unrecouped portion of the permanent land improvements made by the lessee if contract is prematurely terminated is often view as a form of security from farm land being sold out from their ability to lease. A schedule of repayment is constructed by amortizing the dollar investment over the period of the contract at the current interest rate. The resulting chart allows the landowner to find the agreed upon fee for early termination of the contract. Contract needs to have provisions for early termination upon one of agreed list if situations happen. These may include death of one of the parties, sale of farm or dissolving of the farm business.

Question: how is a schedule of repayment constructed?

Answer: by amortizing the dollar investment over the period of the contract at the current interest rate

Kelley, L. (2009c). Irrigation Fact Sheet #9 - Michigan Large Volume Water Use Requirements. https://www.canr.msu.edu/uploads/235/67987/lyndon/9largewaterwith.pdf


Context: (1a) Existing on February 28, 2006 ' Subject to water use reporting. These withdrawals from either wells or surface water are exempt from the new adverse resource impact standards. This is often termed as "Grandfathering", but these withdrawals may still be required to share the water resource with both other "grandfathered" users and with all new users since the legislation still hold Michigan's water use as a riparian right.

Question: why might withdrawals existing on February 28, 2006 still be required to share the water resource information with both other "grandfathered" users and with all new users?

Answer: since the legislation still hold Michigan's water use as a riparian right

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: Both acts use the same definition for a "large capacity well". Large capacity wells are those with the capacity to withdraw 100000 gallons per day (70 gal/min) on average in any consecutive 30-day period. The combined capacity of more than one well at a site that is 100000 gallons or greater capacity/day (70 gal/min), also meets the large capacity well definition. Water use reporting also includes surface water withdrawals with single or combined capacity at a site of 100000 gal/day (70 gal/min) on average, in any consecutive 30-day period. All agricultural water uses (irrigation, cooling, animal watering, etc.) will apply to these laws. Well pumping capacity is included in the well log that should have been filed if the well was drilled after 1968 and are generally available at the local health department, from well drillers or at the MDEQ website.

Question: Where is well pumping capacity filed?

Answer: the well log

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: Act PA 148 established state-wide groundwater mapping and water use reporting. This law created a groundwater resource map of the state and establishes a groundwater advisory committee to direct groundwater protection efforts in the future. The MDA will assemble township-based reports annually and forward them to the MDEQ.

Question: Who assembles township-based water reports?

Answer: The MDA

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Question: how often should a flow meter be calibrated?

Answer: at least annually

Kelley, L. (2014a). Irrigation Fact Sheet #7- Reducing and Evaluating Irrigation Runoff.Instantaneous irrigation application rates compared to soil infiltration rates. https://www.canr.msu.edu/uploads/235/67987/FactSheets/7_ReducingAndEvalRunoff.pdf


Context: Determining the irrigation application rate is part of the planning process for new irrigation systems. The average irrigation application rate at a point along the machine is the amount of water applied divided by the elapsed time from the first drop of water landing at a point in the field, to the last water hitting the point typically expressed as inches per hour.

Question: what is determining the irrigation application rate an important part of?

Answer: the planning process for new irrigation systems

Kelley, L. (2009c). Irrigation Fact Sheet #9 - Michigan Large Volume Water Use Requirements. https://www.canr.msu.edu/uploads/235/67987/lyndon/9largewaterwith.pdf


Context: (3) On and after July 9, 2009 ' Large quantity water withdrawals proposed after July 8, 2009 must receive a favorable assessment from 'Michigan's Water Withdrawal Assessment Tool' or an approval from a requested site-specific review by the MDEQ and be registered before proceeding. If a site-specific review by the MDEQ or an evaluation by the Water Withdrawal Assessment Tool determines that a proposed withdrawal is a zone A or a zone B withdrawal, there is a rebuttable presumption that the withdrawal, as specified in the review or tool, will not cause an adverse resource impact. As previously stated penalties are in place for causing an adverse resource impact.

Question: what must large quantity water withdrawals proposed after July 8, 2009 receive to proceed in the registration process?

Answer: a favorable assessment from 'Michigan's Water Withdrawal Assessment Tool' or an approval from a requested site-specific review by the MDEQ and be registered before proceeding

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Context: (5) Irrigation Scheduler: is a simple computerized irrigation scheduling checkbook model from the Agronomy Department of Purdue University. This method can be used throughout Michigan and Indiana. Crop specific E.T. values are estimated using the daily high and low temperatures and rainfall provided by the producer or weather data can be imported from the internet.

Question: How are crop specific evapotranspiration values estimated using Irrigation Scheduler?

Answer: using the daily high and low temperatures and rainfall provided by the producer or weather data can be imported from the internet

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: P.A. 33 of 2006 amended Michigan's Natural Resources Protection Act as part 327 of 451. Changes included: (a) No "Adverse resource impact" Part 327 of 451 establishes "adverse resource impact" as the standard that all large capacity water users must meet for withdraws constructed after February 2006. Through February 2008 this applies specifically to a restriction on wells constructed within 1320 ft. of designated trout streams unless the well is over 150 ft. deep or potential need for proof of "no adverse resource impact". Many of the Michigan groundwater stewardship technicians or MSU Extension agriculture educators can guide you in the use of these tools.

Question: What did P.A. 33 of 2006 accomplish?

Answer: amended Michigan's Natural Resources Protection Act as part 327 of 451

Kelley, L. (2013). Irrigation Fact Sheet #12 - Nitrogen Application with Irrigation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/12_NitrogenApplicationWithIrrigationFact_Sheet.pdf


Context: The inherent risk of injecting fertilizer into a water system dictates the need for backflow protection. Both Indiana and Michigan have resource protection rules that require the use of Chemigation valves for the protection of both surface and ground water sources. Chemigation valves create an air gap in the pipe line downstream from the pump when the pump is shut down. The air gap breaks the suction created by water retreat back to groundwater or surface water. Chemigation valves for most irrigation application are available from local irrigation dealers for less than $700. Installation cost is much less at the time of pump installation and should be included in almost all new irrigation pumping installations.

Question: when is the installation cost of Chemigation valves the cheapest?

Answer: at the time of pump installation

Kelley, L. (2011). New irrigation planning checklist - MSU Extension. https://www.canr.msu.edu/news/new_irrigation_planning_checklist


Context: (2) Ground water availability. Irrigation is not profitable without a reliable and adequate source of water. Nearby large volume irrigation, municipal or industrial wells are an excellent source of water availability. Well drillers familiar with large volume wells in your area are also excellent resources. Michigan has available groundwater mapping tools that can help evaluate potential water withdrawal sites.

Question: what resources does Michigan have available that can help evaluate potential water withdrawal sites?

Answer: groundwater mapping tools

Kelley, L. (2013). Irrigation Fact Sheet #12 - Nitrogen Application with Irrigation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/12_NitrogenApplicationWithIrrigationFact_Sheet.pdf


Question: what should be included in almost all new irrigation pumping installations?

Answer: Chemigation valves

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Context: Option to purchase the farm in future: (a) "First right of refusal" option allows the lessee to purchase the land at the highest offer received. The term "first right of refusal" refers to the lessee having the right to purchase the property if sold in the contract period. The sale to another party can only proceed if the lessee having the "first right of refusal" refuses to purchase the property. First right of refusal options may reduce the potential sale value of a property by removing one of the most motivated and common buyer of property, the lessee, from the bidding process.

Question: how will the first right of refusal reduce the potential sale value of the property?

Answer: by removing one of the most motivated and common buyer of property, the lessee, from the bidding process

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Question: What is DIRTI shorthand for?

Answer: (Depreciation, Interest, Repairs, Taxes, and Insurance) formula

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Question: how should weather data be acquired if the producer cannot provide daily temperature and rainfall data to Irrigation Scheduler?

Answer: weather data can be imported from the internet

Kelley, L. (2013). Irrigation Fact Sheet #12 - Nitrogen Application with Irrigation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/12_NitrogenApplicationWithIrrigationFact_Sheet.pdf


Context: Irrigated production has the advantage of fertigation as an option in nitrogen management. Fertigation is the process of applying fertilizer through irrigation water. Liquid 28% nitrogen is the most common product for fertigation, but urea and micro-nutrient solutions are also available to meet crop nutrient needs, with proper equipment.

Question: what is fertigation?

Answer: the process of applying fertilizer through irrigation water

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Question: where can Irrigation Scheduler be used?

Answer: throughout Michigan and Indiana

Kelley, L. (2009). Irrigation Fact Sheet #9 - Michigan Large Volume Water Use Requirements. https://www.canr.msu.edu/uploads/235/67987/lyndon/9largewaterwith.pdf


Context: (1b) Large volume water withdrawals that have not been reported on previously could have been added to the 2008 report due April 1, 2009 to gain their "grandfathered" status and avoid the potent $1000/year fine. The 2008 large volume water use report is part of the Agricultural Water Conservation Plan. MDA has also made available it's "MICHIGAN DEPARTMENT OF AGRICULTURE NEW LARGE QUANTITY WATER WITHDRAWAL REGISTRATION FORM". Contrary to its title this form could be used to register withdrawals that where constructed prior to February 28, 2006 by filling in the date constructed.

Question: what has Michigan's Department of Agriculture (MDA) also made available to register withdrawals constructed prior to February 28, 2006?

Answer: MICHIGAN DEPARTMENT OF AGRICULTURE NEW LARGE QUANTITY WATER WITHDRAWAL REGISTRATION FORM

Kelley, L., & Miller, S. (2019). Irrigation Fact Sheet #3 - Irrigation Scheduling Tools. https://www.canr.msu.edu/uploads/236/43605/FactSheets/3_IrrigationSchedulingTools5.14.pdf


Context: (2) The MSU Soil Water Balance Sheet: is a paper version of a checkbook scheduler producers can use Reference Evapotranspiration (E.T.) Data from their own E.T. gauge station or Reference E.T. data form Purdue's PAC center weather stations. For Michigan, producers can use the Enviroweather data listed above. The Soil Water Balance Sheet helps producers convert the Reference E.T. into a estimate water removal for either corn or soybeans in their field.

Question: what does the MSU Soil Water Balance Sheet help producers with?

Answer: convert the Reference E.T. into a estimate water removal for either corn or soybeans in their field

Kelley, L., Miller, S., & Loudon, T. (2006). Irrigation Fact Sheet #1- Agricultural Water Use Reporting for 2006 Changes in Water Use Regulation. https://www.canr.msu.edu/uploads/235/67987/FactSheets/1_AgWaterUseReporting11-29-06.pdf


Context: Land rent pricing: Establishment of irrigated rental value is relatively straight forward when all of the irrigation equipment and water supply is the landowners. Average current rent value is available from State and Federal Agricultural Statistic Services or your Agricultural Economics Department from your States Extension service. Talking to neighbors that rent irrigated land is one of the best ways to get a feel for irrigated rental value. Land rent auction can also be used to establish rent value but a solid structure for the process is necessary.

Question: what is a resource that can help establish land rent value?

Answer: Land rent auction can also be used to establish rent value

Kelley, L. (2009a). Irrigation Fact Sheet #6 - Irrigation Aspects of Land Lease Agreements. https://www.canr.msu.edu/uploads/235/67987/lyndon/LandRent.pdf


Context: Sub-leasing: One major issue that needs to be considered in the negotiations of adding irrigation is the ability for the lessee to sublet the property. As high dollar specialty crop become more common in the area opportunity to rent irrigated land for a single production year for nearly double the local irrigated rent rate become a reality. Annual sub-renting could leave land owners with an unfamiliar face to deal with if neighbor water well issue arises. Addressing sub-leasing issue in writing can avoid grief and confusion in the future.

Question: what becomes a reality as high dollar specialty crop become more common in the area?

Answer: opportunity to rent irrigated land for a single production year for nearly double the local irrigated rent rate

Nygren, A. (2017). Value of Using Sensors to Manage Irrigation and Tips for Proper Installation | UNL Water. https://water.unl.edu/article/agricultural-irrigation/value-using-sensors-manage-irrigation-and-tips-proper-installation


Context: Soil Sensor Install Tips: If you are installing Watermark sensors, remember to check them before installation to ensure that they are reading properly. When dry, sensors should read 199 kPa. After soaking in water for 10-15 minutes, sensors should read between 0-10 kPa. Values higher than this likely indicate that the sensor needs to be replaced. Before you go to the field to install Watermark sensors, be sure to put the sensors in water and install them wet to eliminate air in the sensor.

Question: if the sensor reading values are higher than 0-10 kPa after soaking it in water for 10-15 minutes what is indicated?

Answer: that the sensor needs to be replaced

Melvin, S. (2017). Predicting Late-Season Irrigation Needs. UNL Water. https://water.unl.edu/article/agricultural-irrigation/predicting-late-season-irrigation-needs


Context: The last few irrigations of the season require some of the most important water management decisions of the year. An extra irrigation may mean wasting 1 to 3 inches of water and 2 to 5 gallons of diesel fuel per acre. Furrow irrigators may want to decide sooner due to the typical higher application amounts with flood, while pivot irrigators can delay the decision and take advantage of any rainfall that may occur.

Question: how many inches of irrigation water per acre could be wasted as a result from an extra irrigation late in the season?

Answer: 1 to 3 inches

Melvin, S. (2017). Predicting Late-Season Irrigation Needs. UNL Water. https://water.unl.edu/article/agricultural-irrigation/predicting-late-season-irrigation-needs


Context: Nebraska Extension has educators and specialist across the state that would be happy to help you develop a plan as well. Feel free to send an email to Steve Melvin if you would like to set up a time to talk.

Question: what resource has educators and specialists across the state that can help a grower develop an irrigation plan?

Answer: Nebraska Extension

Melvin, S., Power, C., Daigh, A., & Taghvaeian, S. (2023). Early Season Irrigation During Drought. UNL CropWatch. https://cropwatch.unl.edu/2023/early-season-irrigation-during-drought


Context: Also, keep in mind the corn roots grow about an inch each day into soil that is at field capacity, providing much of the water the plants need for that day. Generally, irrigation needs to be delayed until the soil begins to dry down. Furthermore, research conducted in the North Platte area has shown that irrigation could be reduced by one to four inches, compared to a fully irrigated crop, during the vegetative period without a significant yield reduction and can stimulate deeper root growth. For more information, go to "Vegetative Growth Stage Irrigation, Is It Needed This Year?"

Question: how far do corn roots grow into soil that is at field capacity and provides the plant much of the water it needs?

Answer: about an inch each day into soil

Melvin, S., Power, C., Daigh, A., & Taghvaeian, S. (2023). Early Season Irrigation During Drought. UNL CropWatch. https://cropwatch.unl.edu/2023/early-season-irrigation-during-drought


Context: Nitrate leaching loss rates typically range from five to 10 pounds of nitrogen for every inch of water lost to deep percolation or drainage in Nebraska (based on in-field research as well as modeling nitrate-nitrogen losses in a Hastings silt loam soil series with over-irrigation during May and June. Source Aaron Daigh, 2023). Leaching losses can be even larger in sandy soil, with values as large as 30 lb/ac for every inch of over-irrigation measured in a loamy sand soil. Over-irrigation is very expensive and something that needs to be avoided.

Question: how large can nitrate leaching loss rates get in over irrigated loamy sand soils in Nebraska?

Answer: values as large as 30 lb/ac for every inch of over-irrigation

Melvin, S. (2023). Study Reviews Farmer Irrigation Scheduling Tendencies in Dry Years. UNL CropWatch. https://cropwatch.unl.edu/2023/study-reviews-farmer-irrigation-scheduling-tendencies-dry-years


Context: Average percent of fields by year fitting into the six categories. The dry years 2020, '21 and '22 are different than the other years. In the weighted average dry years, 2020, 2021, 2022, 64% were ranked good, 11% were fair, 3% were wet late, 15% were wet early, 3% were wet all season, and 4% were very wet all season.

Question: what percentage of Nebraska fields were ranked fair in the dry years of 2020, 2021, and 2022?

Answer: 11%

Heeren, D., Barker, J. B., Lo, T. H., Melvin, S., Martin, D., & Luck, J. (2017). Considerations in Adopting Variable Rate Irrigation | UNL Water. https://water.unl.edu/article/agricultural-irrigation/considerations-adopting-variable-rate-irrigation


Context: There is increasing pressure on our water resources. Concerns about natural ecosystems and the sustainability of groundwater withdrawals are heightening. Domestic and international competition for water between different users is increasing. Agricultural demand by a global population growing both in number and in wealth is rising.

Question: what is happening to domestic and international competition for water between different users?

Answer: increasing.

Heeren, D., Barker, J. B., Lo, T. H., Melvin, S., Martin, D., & Luck, J. (2017). Considerations in Adopting Variable Rate Irrigation | UNL Water. https://water.unl.edu/article/agricultural-irrigation/considerations-adopting-variable-rate-irrigation


Context: All these trends prompt us to manage our water more precisely. Specifically, irrigation-the largest user of freshwater in Nebraska and worldwide-can be applied more precisely. Besides improving when irrigation is applied (i.e., irrigation scheduling), where irrigation is applied (spatially) can be improved as well.

Question: what are two examples of improvements that can be made to irrigation?

Answer: improving when irrigation is applied (i.e., irrigation scheduling), where irrigation is applied (spatially) can be improved

Yonts, C. D., Melvin, S., & Eisenhauer, D. E. (2008). Predicting the Last Irrigation of the Season. UNL Extension Publications. https://extensionpubs.unl.edu/publication/g1871/html/view


Context: Table I. Normal water requirements for corn, grain sorghum, soybeans, and dry beans between various stages of growth and maturity in Nebraska. For Soybeans R4 crop stage, the stage of growth is known as end of pod elongation, the approximate days to maturity is 37, and the water use to maturity is 9.0 inches. For Soybeans R5 crop stage, the stage of growth is known as beginning of seed enlargement, the approximate days to maturity is 29, and the water use to maturity is 6.5 inches.  For Soybeans R6 crop stage, the stage of growth is known as end of seed elongation, the approximate days to maturity is 18, and the water use to maturity is 3.5 inches.  For Soybeans R6.5 crop stage, the stage of growth is known as leaves begin to yellow, the approximate days to maturity is 10, and the water use to maturity is 1.9 inches.  For Soybeans R7 crop stage, the stage of growth is known as beginning maturity, the approximate days to maturity is 0, and the water use to maturity is 0.0 inches.

Question: what is the approximate water use to maturity for soybeans in the R5 crop stage, the stage of growth that is known as beginning of seed enlargement?

Answer: 6.5 inches

Yonts, C. D., Melvin, S., & Eisenhauer, D. E. (2008). Predicting the Last Irrigation of the Season. UNL Extension Publications. https://extensionpubs.unl.edu/publication/g1871/html/view


Context: Table II. Total available water in top 4 feet if soil is at field capacity and minimum balances at physiological maturity. For silt clay or clay, the available water in 1 foot of soil at 100% of available water is 1.6 in/ft, the available water in top 4 feet at 100% of available water is 6.4 in/4 ft, and minimum balance in top 4 feet at 40% of available water is 2.6 in/ft. For fine sandy loam, silty clay loam, or clay loam, the available water in 1 foot of soil at 100% of available water is 1.8 in/ft, the available water in top 4 feet at 100% of available water is 7.2 in/4 ft, and minimum balance in top 4 feet at 40% of available water is 2.9 in/ft. For sandy clay loam, the available water in 1 foot of soil at 100% of available water is 2.0 in/ft, the available water in top 4 feet at 100% of available water is 8.0 in/4 ft, and minimum balance in top 4 feet at 40% of available water is 3.2 in/ft.

Question: what is the amount of available water in units of (in/ft) for silt clay or clay at 100% of available water in the top 4ft of soil?

Answer: 6.4 in/4 ft

Nygren, A. (2017). Value of Using Sensors to Manage Irrigation and Tips for Proper Installation | UNL Water. https://water.unl.edu/article/agricultural-irrigation/value-using-sensors-manage-irrigation-and-tips-proper-installation


Question: what should a Watermark sensor read in kPa after soaking it in water for 10-15 minutes?

Answer: 0-10 kPa

Nygren, A. (2017). Value of Using Sensors to Manage Irrigation and Tips for Proper Installation | UNL Water. https://water.unl.edu/article/agricultural-irrigation/value-using-sensors-manage-irrigation-and-tips-proper-installation


Context: ETgage Install Tips: As with soil sensors, early installation of atmometers or ETgages is important, so remember to take the time to get them out now (Figure 4).  By installing early, we will make sure that everything is working properly during less critical growth stages and reinforces the importance of reading the ET gage every week. Remember to use distilled water when you are setting up your ETgage.

Question: what type of water should be used when setting up your ETgage?

Answer: distilled water

Melvin, S. (2023a). How to Determine the Chemigation Injection Pump Setting for a Center Pivot with the End Gun Off and On. UNL CropWatch. https://cropwatch.unl.edu/2023/how-determine-chemigation-injection-pump-setting-center-pivot-end-gun-and


Context: Thus, the pivot should operate at a 90% timer setting when the end gun is off and slow to 77.4% when it is on to apply the 30 lbs/acre nitrogen both when the end gun is off, as well as when it is on. The water application will be different - 0.29 inches when the end gun is off and about 0.33 inches when it is on - but the nitrogen rate will remain the same with the constant injection rate pump. The concept behind this method is that the pivot will irrigate the same number of acres per hour, thus the lower cost fixed-rate injection pump will work correctly.

Question: what will be affected if the end gun is on or off?

Answer: The water application

Divine, D. (2017). An Overview of Secondary Aquifers in Nebraska | UNL Water. https://water.unl.edu/article/agricultural-irrigation/overview-seondary-aquifers-nebraska


Context: The Upper Cretaceous aquifer supplies water to only about 13 wells, mostly in western Scotts Bluff County, although it is heavily used in the Denver area. The Upper Cretaceous aquifer has high sodium, and sometimes high chloride concentrations in Nebraska.

Question: how many wells does the Upper Cretaceous aquifer supply water for in western Scotts Bluff County?

Answer: 13

Yonts, C. D., Melvin, S., & Eisenhauer, D. E. (2008). Predicting the Last Irrigation of the Season. UNL Extension Publications. https://extensionpubs.unl.edu/publication/g1871/html/view


Context: Table I. Normal water requirements for corn, grain sorghum, soybeans, and dry beans between various stages of growth and maturity in Nebraska. For Grain Sorghum stage 6 crop stage, the stage of growth is known as half bloom, the approximate days to maturity is 34, and the water use to maturity is 9.0 inches. For Grain Sorghum stage 7 crop stage, the stage of growth is known as soft dough, the approximate days to maturity is 23, and the water use to maturity is 5.0 inches. For Grain Sorghum stage 8 crop stage, the stage of growth is known as hard dough, the approximate days to maturity is 12, and the water use to maturity is 2.0 inches. For Grain Sorghum stage 9 crop stage, the stage of growth is known as physiological maturity, the approximate days to maturity is 0, and the water use to maturity is 0.0 inches.

Question: what is the approximate water use to maturity for grain sorghum in the stage 6 crop stage, the stage of growth that is known as half bloom?

Answer: 9.0 inches

Melvin, S., Power, C., Daigh, A., & Taghvaeian, S. (2023). Early Season Irrigation During Drought. UNL CropWatch. https://cropwatch.unl.edu/2023/early-season-irrigation-during-drought


Context: Risk of Early Season Leaching Excess irrigation has its own risks. Generally, when the soil is above field capacity, excess water leaves the root zone, called deep percolation. This is an essential function of the soil for groundwater recharge. When deep percolation takes agrichemicals past the root zone, it is called leaching. May and June are the most critical time for leaching losses all year.

Question: what is deep percolation an essential function of the soil for?

Answer: groundwater recharge

Barker, J. B. (2017). Considerations in Adopting Variable Rate Irrigation for Center Pivots and Lateral Systems. http://extensionpublications.unl.edu/assets/pdf/ec2000.pdf.


Context: The description of a speed control VRI system is that its application rate is varied by changing the speed of the pivot and that the irrigation management zones are pie slice shaped. Considerations for the speed control VRI system are that it is relatively inexpensive - many picot panels are capable without additional investment. It also needs no special hardware on the sprinklers. Example uses of it are if spatial variation lines up well with pie slices, varying application based on topography (e.g. reduced application on low spots) if it lines up pie slices, multiple crops or varieties under one pivot, and on-farm research.

Question: what is not required on the sprinklers of a speed control VRI system?

Answer: special hardware

Yonts, C. D., Melvin, S., & Eisenhauer, D. E. (2008). Predicting the Last Irrigation of the Season. UNL Extension Publications. https://extensionpubs.unl.edu/publication/g1871/html/view


Context: Table I. Normal water requirements for corn, grain sorghum, soybeans, and dry beans between various stages of growth and maturity in Nebraska. For Corn R2 crop stage, the stage of growth is known as blister, the approximate days to maturity is 45, and the water use to maturity is 10.5 inches. For Corn R4 crop stage, the stage of growth is known as dough, the approximate days to maturity is 34, and the water use to maturity is 7.5 inches. For Corn R4.7 crop stage, the stage of growth is known as beginning dent, the approximate days to maturity is 24, and the water use to maturity is 5.0 inches. For Corn R5 crop stage, the stage of growth is known as 1/4 milk line, the approximate days to maturity is 19, and the water use to maturity is 3.75 inches. For Corn R5 crop stage, the stage of growth is known as 1/2 milk line - full dent, the approximate days to maturity is 13, and the water use to maturity is 2.25 inches. For Corn R5 crop stage, the stage of growth is known as 13/4 milk line, the approximate days to maturity is 7, and the water use to maturity is 1.0 inches. For Corn R6 crop stage, the stage of growth is known as physiological maturity, the approximate days to maturity is 0, and the water use to maturity is 0.0 inches.

Question: what is the approximate water use to maturity for corn in the R2 crop stage, the stage of growth that is known as blister?

Answer: 10.5 inches

Melvin, S. (2023b). Study Reviews Farmer Irrigation Scheduling Tendencies in Dry Years. UNL CropWatch. https://cropwatch.unl.edu/2023/study-reviews-farmer-irrigation-scheduling-tendencies-dry-years


Context: Now is the time to get the probes in the ground. While other tasks may seem more pressing, early installation of sensors is important to ensure proper operation during the later critical growth phases. Early installation helps to minimize root and leaf damage and makes it easy to get around the field with the pickup or ATV to install the equipment.

Question: why is early installation of soil sensors critical?

Answer: to ensure proper operation during the later critical growth phases

Melvin, S., Power, C., Daigh, A., & Taghvaeian, S. (2023). Early Season Irrigation During Drought. UNL CropWatch. https://cropwatch.unl.edu/2023/early-season-irrigation-during-drought


Context: Soil water monitoring data is easier to analyze once the crop has taken up water at the 16- to 24-inch depth during the vegetative growth stage. This drier zone can then be monitored with sensors to see if the area gets wetter or drier. If it keeps getting drier, the irrigation system needs to keep running. However, if it starts to get wetter, then stop irrigating for a few days. Ideally, the drier zone should slowly expand deeper with the crop using most of the subsoil water by the time the crop matures. For more information on this scheduling strategy, watch the Advanced Irrigation Scheduling Techniques video.

Question: what can be used to monitor if the 16- to 24-inch depth area is getting wetter or drier?

Answer: sensors

Yonts, C. D., Lyon, D. J., Harveson, R. M., Hergert, G. W., Hein, G. L., & Santra, D. (2009). Producing Irrigated Winter Wheat. https://extensionpubs.unl.edu/publication/ec731/pdf/view/ec731-2009.pdf


Context: For winter wheat in the boot/heading crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 1.30 inches and the estimated water use during the week of June 19-25, 2023 is 1.50 inches. For winter wheat in the soft dough crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 1.18 inches.

Question: what is the estimated water usage for winter wheat during the boot/heading crop growth stage during the week of June 19-25 in 2023?

Answer: 1.50 inches

Kranz, B. (2018). Economics of Variable Frequency Drives for Irrigation Pumps. UNL CropWatch. https://cropwatch.unl.edu/2018/economics-variable-frequency-drives-irrigation-pumps


Context: Overall, our results indicate that an electric motor running at a constant 1770 rpm will use excess energy for much of the center pivot revolution. VFD operation includes the installation of a pressure sensor somewhere on the system. The controller part of the VFD adjusts the motor speed to maintain a set pipeline pressure wherever the sensor is positioned. Some sensors are placed at the pump outlet, but if the irrigated area has a lot of topography, that position is often the worst location for the sensor.

Question: what rpm does a constant electric motor have to run at to use excess energy for much of the center pivot revolution?

Answer: 1770 rpm

Yonts, C. D., Melvin, S., & Eisenhauer, D. E. (2008). Predicting the Last Irrigation of the Season. UNL Extension Publications. https://extensionpubs.unl.edu/publication/g1871/html/view


Context: Table II. Total available water in top 4 feet if soil is at field capacity and minimum balances at physiological maturity. For loam, very fine sandy loam, or silt loam topsoil which is silty clay loam or silty clay subsoil, the available water in 1 foot of soil at 100% of available water is 2.0 in/ft, the available water in top 4 feet at 100% of available water is 8.0 in/4 ft, and minimum balance in top 4 feet at 40% of available water is 3.2 in/ft. For loam, very fine sandy loam, or silt loam topsoil which is medium textured subsoil, the available water in 1 foot of soil at 100% of available water is 2.5 in/ft, the available water in top 4 feet at 100% of available water is 10.0 in/4 ft, and minimum balance in top 4 feet at 40% of available water is 4.0 in/ft.

Question: what is the available water in 4ft of soil at 100% of available water for loam, very fine sandy loam, or silt loam topsoil which is silty clay loam or silty clay subsoil?

Answer: 8.0 in/4 ft

Melvin, S. (2023a). How to Determine the Chemigation Injection Pump Setting for a Center Pivot with the End Gun Off and On. UNL CropWatch. https://cropwatch.unl.edu/2023/how-determine-chemigation-injection-pump-setting-center-pivot-end-gun-and


Context: Both methods require the basic information for the pivot. All the needed details can be found on the sprinkler chart for the center pivot. The sprinkler chart is the documentation that came with the sprinkler package for the pivot and describes the basic layout of the pivot, water flow rate, pressure, size of each sprinkler, etc. If the current sprinklers on the pivot came with the machine when it was new, the pivot dealer should be able to provide a copy. Otherwise, ask the company that sold the current sprinkler package for it. If you do not have the sprinkler chart, then you will need to determine the needed data by measuring the pivot.

Question: what does the sprinkler char describe?

Answer: basic layout of the pivot, water flow rate, pressure, size of each sprinkler, etc.

Melvin, S. (2023). Study Reviews Farmer Irrigation Scheduling Tendencies in Dry Years. UNL CropWatch. https://cropwatch.unl.edu/2023/study-reviews-farmer-irrigation-scheduling-tendencies-dry-years


Context: Average percent of fields by year fitting into the six categories. The dry years 2020, '21 and '22 are different than the other years. In 2022, out of 60 reports, 70% were ranked good, 8% were fair, 3% were wet late, 15% were wet early, 2% were wet all season, and 2% were very wet all season.

Question: In 2022 out of 60 reports, what percentage of Nebraska fields were ranked fair?

Answer: 8%

Melvin, S. (2023a). How to Determine the Chemigation Injection Pump Setting for a Center Pivot with the End Gun Off and On. UNL CropWatch. https://cropwatch.unl.edu/2023/how-determine-chemigation-injection-pump-setting-center-pivot-end-gun-and


Context: When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.02, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.96. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.03, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.94. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.04, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.92. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.05, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.91. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.06, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.89. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.07, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.87. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.08, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.86. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.09, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.84. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.1, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.83. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.11, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.81. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.12, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.8. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.13, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.78. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.14, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.77. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.15, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.76. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.16, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.74. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.17, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.73. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.18, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.72. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.19, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.71. When the ratio of the end gun throw (Rg) to the pivot length (R) is 0.2, the the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) is 0.69.

Question: what is the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) when the ratio of the end gun throw (Rg) to the pivot length (R) is 0.11?

Answer: 0.81

Melvin, S. (2023a). How to Determine the Chemigation Injection Pump Setting for a Center Pivot with the End Gun Off and On. UNL CropWatch. https://cropwatch.unl.edu/2023/how-determine-chemigation-injection-pump-setting-center-pivot-end-gun-and


Question: what is the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) when the ratio of the end gun throw (Rg) to the pivot length (R) is 0.2?

Answer: 0.69

Ingram, T. (2017). Is Your Irrigation System Ready For the Season? | UNL Water. https://water.unl.edu/article/agricultural-irrigation/your-irrigation-system-ready-season


Context: 2) Pump - The pump is a piece that is sometimes overlooked.  Before you start irrigating in the spring make sure you start the dripper to get the line shaft bearings lubed.  It needs 1 gallon of drip oil for every 100 feet of depth.  Set the dripper for 1 drip every 5 seconds.  The pump can only take oil so fast and you can't over oil them.  Also make sure the dripper line is attached and the fittings are tight.

Question: what is a piece of the irrigation system that often gets overlooked?

Answer: The pump

Nygren, A. (2017). Value of Using Sensors to Manage Irrigation and Tips for Proper Installation | UNL Water. https://water.unl.edu/article/agricultural-irrigation/value-using-sensors-manage-irrigation-and-tips-proper-installation


Context: To learn more about the secondary aquifers of Nebraska, download the Conservation and Survey Division publication titled 'An Overview of Secondary Aquifers in Nebraska' available at http://digitalcommons.unl.edu/conservationsurvey/138. Questions regarding western Nebraska aquifers may be directed to xxxxx xxxxxx atxxxxxxxxxxxxx; questions regarding eastern Nebraska aquifers may be directed to xxxx xxxxxx atxxxxxxxxxxxxx.

Question: how can steve sibray be contacted?

Answer: xxxxxxxxxxxx

Divine, D. (2017). An Overview of Secondary Aquifers in Nebraska | UNL Water. https://water.unl.edu/article/agricultural-irrigation/overview-seondary-aquifers-nebraska


Context: Benefits from Using Sensors: One of the main benefits of using sensors to better manage irrigation is the reduced costs of pumping. When surveyed, users of sensors from the Nebraska Ag Water Management Network and industry have indicated water savings of 2 inches per acre. The cost of applying an additional 2 inches of water is going to vary depending on your depth to water, system pressure, and equipment costs, but could easily run from $10 to $30 per acre.

Question: how many inches per acre of water savings were indicated by users of sensors from the Nebraska Ag Water Management Network and industry when surveyed?

Answer: 2 inches per acre

Ingram, T. (2017). Is Your Irrigation System Ready For the Season? | UNL Water. https://water.unl.edu/article/agricultural-irrigation/your-irrigation-system-ready-season


Question: how many gallons of drip oil are need for every 100 feet of depth?

Answer: 1 gallon of drip oil

Yonts, C. D., Lyon, D. J., Harveson, R. M., Hergert, G. W., Hein, G. L., & Santra, D. (2009). Producing Irrigated Winter Wheat. https://extensionpubs.unl.edu/publication/ec731/pdf/view/ec731-2009.pdf


Question: what is the estimated water usage for winter wheat during the soft dough crop growth stage during the week of June 12-18 in 2023?

Answer: 1.18 inches

Yonts, C. D., Melvin, S., & Eisenhauer, D. E. (2008). Predicting the Last Irrigation of the Season. UNL Extension Publications. https://extensionpubs.unl.edu/publication/g1871/html/view


Question: what is the available water in top 4ft of soil at 100% of available water for loam, very fine sandy loam, or silt loam topsoil which is medium textured subsoil?

Answer: 10.0 in/4 ft

Divine, D. (2017). An Overview of Secondary Aquifers in Nebraska | UNL Water. https://water.unl.edu/article/agricultural-irrigation/overview-seondary-aquifers-nebraska


Context: Other secondary aquifers in eastern Nebraska include the Niobrara aquifer (230 wells, mostly in Cedar County), the Codell aquifer (70 wells in Knox and Boyd counties), and the Western Interior Plains Aquifer System. Only one active well is currently installed in the Western Interior Plains Aquifer System in Nebraska, but the aquifer system was a historic source of water to the Omaha area, and still supplies huge volumes of water to Iowa and other states to our east.

Question: what aquifer was historically a source of water to the Omaha area?

Answer: the Western Interior Plains Aquifer System

Divine, D. (2017). An Overview of Secondary Aquifers in Nebraska | UNL Water. https://water.unl.edu/article/agricultural-irrigation/overview-seondary-aquifers-nebraska


Question: what is one of the main benefits to using sensors to better manage irrigation?

Answer: the reduced costs of pumping

Melvin, S. (2023a). How to Determine the Chemigation Injection Pump Setting for a Center Pivot with the End Gun Off and On. UNL CropWatch. https://cropwatch.unl.edu/2023/how-determine-chemigation-injection-pump-setting-center-pivot-end-gun-and


Question: what is the pivot speed with the end gun on (Se) compared to the speed with the end gun off (S) when the ratio of the end gun throw (Rg) to the pivot length (R) is 0.15?

Answer: 0.76

Melvin, S. (2023). Study Reviews Farmer Irrigation Scheduling Tendencies in Dry Years. UNL CropWatch. https://cropwatch.unl.edu/2023/study-reviews-farmer-irrigation-scheduling-tendencies-dry-years


Context: The conclusion is that many irrigators could save money, water and nitrogen by using data from irrigation scheduling systems to make data-driven decisions to help them feel confident they are getting optimal yields without putting on extra water just for insurance purposes. Otherwise, irrigators follow their natural tendencies to put on about the same amount of water as in the past and just slightly adjust it for dry or wet years. For more information on yield losses, take time to read the following NebGuide: Plant Growth and Yield as Affected by Wet Soil Conditions Due to Flooding or Over-Irrigation.

Question: for more information on yield losses from bad irrigation systems what can an irrigator read?

Answer: NebGuide: Plant Growth and Yield as Affected by Wet Soil Conditions Due to Flooding or Over-Irrigation

Melvin, S. (2023). Study Reviews Farmer Irrigation Scheduling Tendencies in Dry Years. UNL CropWatch. https://cropwatch.unl.edu/2023/study-reviews-farmer-irrigation-scheduling-tendencies-dry-years


Context: Average percent of fields by year fitting into the six categories. The dry years 2020, '21 and '22 are different than the other years. In 2017, out of 86 reports, 28% were ranked good, 10% were fair, 13% were wet late, 13% were wet early, 22% were wet all season, and 14% were very wet all season.

Question: In 2017 out of 86 reports, what percentage of Nebraska fields were ranked good?

Answer: 28%

Nygren, A. (2017). Value of Using Sensors to Manage Irrigation and Tips for Proper Installation | UNL Water. https://water.unl.edu/article/agricultural-irrigation/value-using-sensors-manage-irrigation-and-tips-proper-installation


Question: how much can an additional 2 inches of water per acre cost?

Answer: easily run from $10 to $30 per acre

Yonts, C. D., Melvin, S., & Eisenhauer, D. E. (2008). Predicting the Last Irrigation of the Season. UNL Extension Publications. https://extensionpubs.unl.edu/publication/g1871/html/view


Context: Table II. Total available water in top 4 feet if soil is at field capacity and minimum balances at physiological maturity. For silt clay or clay, the available water in 1 foot of soil at 100% of available water is 1.6 in/ft, the available water in top 4 feet at 100% of available water is 6.4 in/4 ft, and minimum balance in top 4 feet at 40% of available water is 2.6 in/ft. For fine sandy loam, silty clay loam, or clay loam, the available water in 1 foot of soil at 100% of available water is 1.8 in/ft, the available water in top 4 feet at 100% of available water is 7.2 in/4 ft, and minimum balance in top 4 feet at 40% of available water is 2.9 in/ft. For sandy clay loam, the available water in 1 foot of soil at 100% of available water is 2.0 in/ft, the available water in top 4 feet at 100% of available water is 8.0 in/4 ft, and minimum balance in top 4 feet at 40% of available water is 3.2 in/ft.

Question: what is the amount of available water in units of (in/ft) for sandy clay loam at 100% of available water in 1 ft of soil?

Answer: 2.0 in/ft

Melvin, S. (2023a). How to Determine the Chemigation Injection Pump Setting for a Center Pivot with the End Gun Off and On. UNL CropWatch. https://cropwatch.unl.edu/2023/how-determine-chemigation-injection-pump-setting-center-pivot-end-gun-and


Question: what is considered the variable for the pivot speed with the end gun on?

Answer: Se

Nygren, A. (2017). Value of Using Sensors to Manage Irrigation and Tips for Proper Installation | UNL Water. https://water.unl.edu/article/agricultural-irrigation/value-using-sensors-manage-irrigation-and-tips-proper-installation


Context: More information about how to assemble and prepare Watermark sensors is available in the following video, https://www.youtube.com/watch?v=jpEsjVO497A. Also, for more tips on sensor installation, please review the following CropWatch article, Irrigation Sensor Installation Tips.

Question: for tips on sensor installation what CropWatch article can be reviewed?

Answer: Irrigation Sensor Installation Tips

Divine, D. (2017). An Overview of Secondary Aquifers in Nebraska | UNL Water. https://water.unl.edu/article/agricultural-irrigation/overview-seondary-aquifers-nebraska


Context: Total dissolved solids and sodium concentrations are uniformly high, but other aspects of water chemistry vary from place to place. Arsenic and uranium concentrations have both been documented to exceed their recommended maximum contaminant levels in places, and Chadron well owners should consider testing their wells for these compounds.

Question: what are uniformly high in the aquifers in western Nebraska?

Answer: Total dissolved solids and sodium concentrations

Divine, D. (2017). An Overview of Secondary Aquifers in Nebraska | UNL Water. https://water.unl.edu/article/agricultural-irrigation/overview-seondary-aquifers-nebraska


Context: Chadron wells average about 350 feet deep, and the majority (64%) are used for domestic supply, but livestock and irrigation wells account for 15% and 12% of the wells, respectively. The biggest challenge to using the Chadron aquifer is poor water quality.

Question: how many feet deep is the average well in the Chadron aquifer?

Answer: 350 feet

Divine, D. (2017). An Overview of Secondary Aquifers in Nebraska | UNL Water. https://water.unl.edu/article/agricultural-irrigation/overview-seondary-aquifers-nebraska


Question: who can questions regarding eastern Nebraska's aquifers be directed to?

Answer: xxxx xxxxxx

Melvin, S. (2017). Predicting Late-Season Irrigation Needs. UNL Water. https://water.unl.edu/article/agricultural-irrigation/predicting-late-season-irrigation-needs


Context: Using this information for a center pivot that is set to apply one inch of water per irrigation, the suggested recommendation would be that the system should be off for the next few days to use some of the remaining water. The next inch of water should be applied within the next seven days. Then, the next irrigation should be recalculated using updated soil water readings. The best way to use the remaining water is to delay the start of the last few irrigations a few days each time and react to any rain that might occur during the period. Slowly using the water in the lower portion of the root zone starting in early to mid-August is much better than keeping the profile full until the very end and expecting the crop to use the water all at once.

Question: what should be used in the lower portion of the root zone starting in early to mid-August?

Answer: water

Rudnick, D. (2016). Sprinkler Irrigation System Maintenance for Improved Uniformity and Application Efficiency | CropWatch | University of Nebraska–Lincoln. https://cropwatch.unl.edu/2016/sprinkler-irrigation-system-maintenance-improved-uniformity-and-application-efficiency


Context: Center pivot irrigation systems are designed and managed to apply water as uniformly as possible to enhance crop production. Uniformity has a direct effect on the system's overall application efficiency, which is a measure of how well an irrigation system delivers water to a crop's root zone.

Question: what type of irrigation systems are designed and managed to apply water as uniformly as possible to enhance crop production?

Answer: Center pivot irrigation systems

Divine, D. (2017). An Overview of Secondary Aquifers in Nebraska | UNL Water. https://water.unl.edu/article/agricultural-irrigation/overview-seondary-aquifers-nebraska


Context: Nebraska is a groundwater-rich state, thanks in part to the High Plains Aquifer. Many people are familiar with the High Plains Aquifer (also sometimes called the Ogallala aquifer), but fewer people know that there are other aquifers in the state. In fact, Nebraska has seven secondary aquifers, which are much smaller in areal extent than the High Plains Aquifer and generally have poorer water quality, but are nonetheless important in places where the High Plains Aquifer and shallow sand gravel deposits are absent.

Question: what is an alternative name for the high plains aquifer?

Answer: Ogallala aquifer

Melvin, S. (2023). Study Reviews Farmer Irrigation Scheduling Tendencies in Dry Years. UNL CropWatch. https://cropwatch.unl.edu/2023/study-reviews-farmer-irrigation-scheduling-tendencies-dry-years


Context: However, the winter and spring of 2022-23 has been an exception for most of Nebraska, with off-season precipitation well below normal. This has highlighted the only downside to leaving the soil dry at the end of the irrigation season: In years when we have a very dry off-season, we will need to pump some water in June to refill the profile before the high water demand days of July arrive. The data showed that some fields were at field capacity at the end of the irrigation season in 2022, but many of the silt loam soil fields would require four to five inches of water to refill the profile. The problem is, without soil water monitoring equipment, one will not know if their field is already refilled to field capacity or not. Other lighter soil texture fields will take less water to refill them.

Question: what is the problem an irrigator will have if they don't have soil water monitoring equipment?

Answer: one will not know if their field is already refilled to field capacity or not

Melvin, S. (2023). Study Reviews Farmer Irrigation Scheduling Tendencies in Dry Years. UNL CropWatch. https://cropwatch.unl.edu/2023/study-reviews-farmer-irrigation-scheduling-tendencies-dry-years


Context: Average percent of fields by year fitting into the six categories. The dry years 2020, '21 and '22 are different than the other years. In 2019, out of 15 reports, 20% were ranked good, 7% were fair, 40% were wet late, 7% were wet early, 0% were wet all season, and 27% were very wet all season.

Question: In 2019 out of 15 reports, what percentage of Nebraska fields were ranked good?

Answer: 20%

Melvin, S. (2023). Study Reviews Farmer Irrigation Scheduling Tendencies in Dry Years. UNL CropWatch. https://cropwatch.unl.edu/2023/study-reviews-farmer-irrigation-scheduling-tendencies-dry-years


Context: Average percent of fields by year fitting into the six categories. The dry years 2020, '21 and '22 are different than the other years. In 2021, out of 53 reports, 57% were ranked good, 6% were fair, 6% were wet late, 25% were wet early, 4% were wet all season, and 4% were very wet all season.

Question: In 2021 out of 53 reports, what percentage of Nebraska fields were considered wet all season?

Answer: 4%

Ingram, T. (2017). Is Your Irrigation System Ready For the Season? | UNL Water. https://water.unl.edu/article/agricultural-irrigation/your-irrigation-system-ready-season


Context: Check for proper operation by making sure there is not any water squirting from the side of any regulators.  This is a sign that the rubber bladder has failed.  Keep in mind that sprinklers and pressure regulators do have a life span.  If your system is approaching 10 years old you might need to take a closer look at them.  Uniformity of water application can suffer greatly if your sprinkler package is out of date.

Question: what components of the irrigation system have a working lifespan and can wear out?

Answer: sprinklers and pressure regulators

Melvin, S., Power, C., Daigh, A., & Taghvaeian, S. (2023). Early Season Irrigation During Drought. UNL CropWatch. https://cropwatch.unl.edu/2023/early-season-irrigation-during-drought


Context: Soil Moisture Monitoring In this drought year, many irrigated fields have very little subsoil moisture, while other portions of Nebraska have experienced significant rains over the last month. With irrigation, any grower can can over-irrigate early and create a wet spring. The most reliable method to know when and how much to irrigate is to monitor soil moisture at multiple depths. Keep in mind that when irrigation is applied with a center pivot an inch at a time on the soil surface, the top foot will stay very wet all summer.

Question: what can create a wet spring for a grower?

Answer: over-irrigate early

Nygren, A. (2017). Value of Using Sensors to Manage Irrigation and Tips for Proper Installation | UNL Water. https://water.unl.edu/article/agricultural-irrigation/value-using-sensors-manage-irrigation-and-tips-proper-installation


Context: ETgage Install Tips: As with soil sensors, early installation of atmometers or ETgages is important, so remember to take the time to get them out now (Figure 4).  By installing early, we will make sure that everything is working properly during less critical growth stages and reinforces the importance of reading the ET gage every week. Remember to use distilled water when you are setting up your ETgage.

Question: when should ETgages or atmometers be installed?

Answer: early

Melvin, S. (2023b). Optimize Those Last Few Irrigations | CropWatch | University of Nebraska–Lincoln. https://cropwatch.unl.edu/2023/optimize-those-last-few-irrigations


Context: University of Nebraska Extension irrigation scheduling recommendations encourage irrigators to allow the crop to continue using more and more of the stored soil water starting in August and continuing into September when the crop matures. The recommendation is to lower the soil water level from the usual summer water condition of a minimum of 50% plant available water in the top three feet of soil to 40% in the top four feet after the dough stage (R4) is reached. Thus, the stored soil water content should be significantly lower when the crop matures in September than earlier in August.

Question: what does the University of Nebraska Extension recommendations encourage irrigators to allow the crop to use more of starting in August and continuing into September when the crop matures?

Answer: stored soil water

Melvin, S. (2023). Study Reviews Farmer Irrigation Scheduling Tendencies in Dry Years. UNL CropWatch. https://cropwatch.unl.edu/2023/study-reviews-farmer-irrigation-scheduling-tendencies-dry-years


Context: The analysis found that all the fields in 2017, '18 and '19 were irrigated to a level preventing water stress all season, however 15% to 20% of the fields may have been underwatered late into the season just a little bit (it may or may not have affected the yield) late in the season in the dry years of 2020, '21 and '22.

Question: what percentage of fields in 2020, 2021, and 2021 were slightly underwatered late into the season?

Answer: 15% to 20%

Kranz, B. (2018). Economics of Variable Frequency Drives for Irrigation Pumps. UNL CropWatch. https://cropwatch.unl.edu/2018/economics-variable-frequency-drives-irrigation-pumps