Context: The chemigation injection pump setting can be easily determined using the sprinkler chart. The method is very simple to use if one has the chart, or at least the speed chart part of it. The information can also be gained from looking at the readout on a computer-style pivot panel or the pivot control app.

Question: What is the easiest way to determine the chemigation injection pump setting using the sprinkler chart?

Answer: if one has the chart, or at least the speed chart part of it

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: Having three phase electric power provided at the location of the pump by your electric service provider is the simplest and safest energy source. It requires the least amount of farm owned/maintained equipment to run irrigation systems. Electric service providers can often generate a cost estimate for adding three phase electric power service to you location. In some situations estimates may be free with a commitment to use a quantity of power in the future. More likely, a simple line drop from a new set of transformers on an existing three phase line may be $500 to $2,000. If three phase power is not near the location, costs to install the service are estimated to be between $10,000 and $30,000 a mile. These costs are to be paid by the potential irrigator to upgrade service in the area

Question: Which power source should I use to save money?

Answer: three phase electric power

Kelley, L. (2013d). Three phase power: The first choice for irrigation energy - MSU Extension. https://www.canr.msu.edu/news/three_phase_power_the_first_choice_for_irrigation_energy


Context: The depth of the sensors should be considered based on the crops root depth The threshold to trigger irrigation depends on the crop type, growth stage, soil water holding capacity, and capacity of the irrigation system Knowing soil types (especially texture) is important for irrigation scheduling because soil water holding capacity is largely determined by soil types.

Question: What information impacts the sensors used and irrigation of crops?

Answer: the crop type, growth stage, soil water holding capacity, and capacity of the irrigation system

Specialty Hybrids. (2023). Soybean Water Use and Irrigation Timing. https://www.specialtyhybrids.com/en-us/agronomy-library/water-use-in-soybean-and-irrigation-timing.html


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 the lower bound of infiltration rates of Michigan soils?

Answer: one-half inch per hour

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: 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: How much of the budget does fertigation take up?

Answer: makes up the remainder of the budget supplying nitrogen to the crop just prior to tassel emergence.

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


Context: (1) Check and test all control and power boxes: With all power off, open each electric box and blow it out with compressed air. Avoid leaving any dust or debris in the box or connections. Seal holes that rodents, snakes or insects may use to gain access to the box. A small application of an insecticide with a long residual time to the bottom of the box can reduce ant and spider problems in the future. Make sure disconnects function and repair or replace faulty equipment. Also make sure all connections are tight and all connection surfaces are free of corrosion. Many electrical disconnects or pivot control boxes meet an early demise from electrified mouse nest explosion in the box.

Question: What is the result of electrified mouse nest explosions?

Answer: Many electrical disconnects or pivot control boxes meet an early demise

Kelley, L. (2017). Irrigation Fact Sheet #15 - Irrigation Inspection and Repair. https://www.canr.msu.edu/uploads/235/67987/factsheets/15_Irriation_Inspection_and_Repair_v2_4.21.17.pdf


Context: Irrigation systems need to be able to replace the typical water use of the plant during a prolonged dry period. System costs increase as capacity increases. Typically water sources capable of 400 to 1200 gallons per minute are used to supply irrigation water. Systems designed to apply 0.25 inch per day (5 gallons/minute/acre of irrigation) can provide adequate water in all but the most extreme situations. Evapotransporation rate (E.T.) is a term that represents the daily water lost by the plants maintenance and growth along with the evaporative loss from the soil surface. E.T. rates for almost all crops grown in northern Indiana and Michigan have rates under 0.25 inch per day for all but a few extreme days.

Question: What is the capacity rate of water sources that are used to supply irrigation water?

Answer: 400 to 1200 gallons per minute

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: (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 conditions would make irrigation not profitable?

Answer: without a reliable and adequate source of water

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: Question: What are the important parameters I should look at in an irrigation water quality report? Excerpt: Most irrigation water analysis reports will provide a list of cations (calcium, magnesium, sodium and potassium) and anions (bicarbonate, carbonate, sulfate and chloride) along with pH, total dissolved solids (TDS), electrical conductivity (EC) and the sodium adsorption ratio (SAR). The cations, anions and TDS will be listed as milligrams per liter (mg/l) or the equivalent, parts per million (ppm). The two most important factors are TDS or EC and SAR. The TDS of a water sample is a measure of the concentration of soluble salts in the water, which include all the cations and anions. TDS is estimated from the EC of the water. The more dissolved minerals in the water, the higher the EC. The units of EC can be listed as millimhos per centimeter (mmhos/cm), micromhos per centimeter (umhos/cm) or deciSiemens per meter (dS/m). One millimho per centimeter is equal to 1000 micromhos per centimeter or 1 dS/m. TDS can be estimated by multiplying the EC (in umhos/cm) by 0.64. For example, the TDS of a water sample with an EC of 2000 umhos/cm (2.0 dS/m) would be about 1280 mg/l. The SAR of a water sample is the proportion of sodium to calcium and magnesium in the water. Since it is a ratio, SAR has no units. For most soils in North Dakota, any water with an EC greater than 2000 micromhos per centimeter (2 mmhos/cm or 2 dS/m) or an SAR value greater than 6 is not generally recommended for continuous irrigation. However, soils with a high sand content can use water with an SAR up to 9.

Question: What EC level in water is generally not recommended for continuous irrigation?

Answer: water with an EC greater than 2000 micromhos per centimeter (2 mmhos/cm or 2 dS/m)

Fipps, G. (2021). Irrigation Water Quality Standards And Salinity Management Strategies. https://irrigation.tamu.edu/files/2021/04/EB-1667.pdf


Context: Estimating Annual Irrigation Costs. Annual irrigation cost can be divided into two categories: annual cost of ownership and the annual cost of operation - mainly the cost of energy and labor. The annual cost of ownership is often estimated 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 can provide you with the annual cost of the original investment in equipment and improvements.

Question: Where can you find the standard procedure pertaining to the DIRTI formula?

Answer: MSU Extension Bulletin E-2131

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: 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: How can I find a fair cost for shared irrigation systems?

Answer: 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.

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


Context: An estimate of expected water use by the month is needed. Most irrigators will estimate their water use from experience multiplied by the number of acres irrigated. As an example: 100 acres with 1.5 inches of irrigation applied in June would have an estimated water use of 150 acre inches for the month. Three inches of estimated irrigation need in both July and August and 1 inch in September would give us an estimated annual water use of 550 acre inches for the year.

Question: If 3 inches of estimated irrigation are needed in both July and August and 1 inch in September, what is the estimated annual water use?

Answer: 550 acre inches for the year

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: Corn management and yield loss: Management depends on the remaining yield potential. Each field provides a unique combination of soil, management, hybrid, and water supply so not all the fields will have the same yield reduction. After pollination a key is to determine how successful pollination was; that is how many kernels per ear were attained. This can be determined by performing a shake test to see if silks are still attached to the ovules (unfertilized kernels); silks will easily drop from fertilized ovules (kernels). Or wait until seven to ten days after pollination when the ear is in the blister stage (plump kernels with watery liquid inside) to see how many kernels are expanding.

Question: Why should I perform a shake test when determining how successful corn pollination was?

Answer: to see if silks are still attached to the ovules (unfertilized kernels

Licht, M., & Archontoulis, S. (2017). Influence of Drought on Corn and Soybean | Integrated Crop Management. https://crops.extension.iastate.edu/cropnews/2017/07/influence-drought-corn-and-soybean


Context: Question: What do I do if my controller shows no display? Excerpt: Check to see if you have power going to the controller.' If not, check circuit breakers & GFI outlets in your home to see if they have been tripped.' If you have power, but no display, unplug controller for 2 minutes then plug back in.' If still no display,' see if there is a reset button on your controller - hold for 10 seconds.' Still no display?' Controller may have gone bad.

Question: What do I do if my controller shows no display?

Answer: Check to see if you have power going to the controller

Carolina Irrigation. (2024). FAQ | Carolina Irrigation | Residential & Commercial Irrigation Experts Since 1999. https://www.carolinairrigation.net/faq


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 are Michigan and Indiana land dominated by?

Answer: contracted specialty crops like vegetable and hybrid seed corn production

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: Effects on soybean during grain fill Drought effects on soybean are generally not as severe as corn. This is a result of overlapping of development stages. When short-term drought stress results in flower or pod abortion, new flowers and pods will set when conditions improve. During prolonged drought stress, or when the stress occurs during pod set and seed filling stages, the compensatory ability is not as likely to occur. Drought can reduce pod number by up to 20 percent as a result of flower and pod abortion. Seeds per pod and seed size can also be affected by drought stress but to a lesser extent than the number of pods. Drought stress often results in earlier maturity or shortening of the grain filling period resulting in lower seed weights and yields. Soybean yield loss from drought stress is compounded by the lack of nitrogen mineralization and nitrogen fixation. In dry conditions, nodules cease nitrogen fixation because of a lack of soil moisture and lack of carbohydrate supply from the soybean plant. If water deficits are short lived, nodule nitrogen fixation can resume.

Question: What happens if the grain filling period is shortened?

Answer: lower seed weights and yields

Licht, M., & Archontoulis, S. (2017). Influence of Drought on Corn and Soybean | Integrated Crop Management. https://crops.extension.iastate.edu/cropnews/2017/07/influence-drought-corn-and-soybean


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 kind of soil requires about half an inch of irrigation to wet the soil profile down five to six inches?

Answer: sandy loam soils

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: According to Michigan State University Extension, if a producer's irrigation capacity is low, this means that the grower should be starting to irrigate prior to peak use or during rainy spells to build moisture level. Many irrigators started too late and could never regain good soil moisture level during the drought of 2012. If you have the capacity to provide one inch every three days, you can afford to gamble on receiving rainfall. For most producers, starting late can lead to poor irrigated yields.

Question: When can I afford to gamble on receiving rainfall?

Answer: If you have the capacity to provide one inch every three days

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


Context: How to Get More Out of Your Irrigation System: (2) Know your actual application. The catch can system available to evaluate the uniformity of the application of your system will also tell you the actual application rate. Your system provider or the website below can provide you with tools to print a corrected percent timer chart if needed.

Question: Where can I find the tools to print a corrected percent timer chart?

Answer: Your system provider

Kelley, L. (2009). Irrigation Fact Sheet #8 - How to Get More from your Irrigation System. https://www.canr.msu.edu/uploads/235/67987/lyndon/HGMIrrSys.pdf


Context: Question: Can all soils be irrigated? Excerpt:All soils can be irrigated but the right irrigation system has to be selected. For example, soils with a high clay content can be irrigated with a trickle (often called drip) irrigation system, a surface irrigation system (if the land has less than 2% slope) and a solid-set sprinkler system, however, a moving sprinkler system like center pivots and lateral moves may not work very well. Conversely, a soil with a high sand fraction on sloping land can be irrigated very well with a moving sprinkler system but not by a surface irrigation system and it may be difficult to use trickle irrigation and solid-set sprinklers due to elevation differences. Center pivots are used to apply water to over 88% of the irrigated land in North Dakota. Due to the preference for moving sprinkler systems, all the soils in the state have been classified as irrigable, conditional and non-irrigable. The irrigable and non-irrigable classifications are self-explanatory but a soil may be conditional for one or more of the following reasons: salinity accumulation concerns, too much slope, irrigation water quality, shallow bedrock, poor drainage characteristics and too much gravel. Successful irrigation also relies on the compatibility of the water quality with the soils in the field. In general, sandy well-drained soils can be irrigated using water with higher TDS and SAR than soils with more clay and silt content.

Question: Why should I not use trickle irrigation and solid-set sprinklers on sandy soil?

Answer: due to elevation differences

NDSU Agriculture. (2024). Irrigation - Frequently Asked Questions. https://www.ndsu.edu/agriculture/ag-hub/ag-topics/crop-production/irrigation-tiling-drainage/irrigation-frequently-asked-questions


Context: Applying nitrogen fertilizer or crop protection products through a center pivot is an efficient and effective method. In fact, it is a well-documented best management practice to apply nitrogen fertilizer as close to the time the corn will use it to get the most efficient use of the fertilizer. Most of the products are injected into the pivot with a fixed rate injection pump. So, how does one figure the pumping rate to set the pump at, and what about the change the end gun causes when it's turned on and off? We will discuss both challenges in this article.

Question: What happens with the products and the pivot?

Answer: Most of the products are injected into the pivot with a fixed rate injection pump

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: Assembly directions - Option 2: 0.5 inch plastic pipe cut in 4 inch section can be drilled with 0.25 inch hole 1 inch from end. 13 inches plastic cable tie secured through the 0.25 inch hole creates a cup holder to fit on top of post. The total cost per unit is less than one dollar and requires only a saw and a drill. The catch can stand will allow data collection in fields with crops up to 30 inches tall. A 500 ml graduated cylinder is used to measure water volume. 500 ml graduated cylinders are available from science lab and beer maker supply stores on the web.

Question: Provide an alternate drilling step when assembling catch can stands.

Answer: 0.5 inch plastic pipe cut in 4 inch section can be drilled with 0.25 inch hole 1 inch from end.

Kelley, L. (2020). Irrigation Fact Sheet #16 - Catch Can Stands for Rain Gauges and Uniformity Check for Evaluating Irrigation.


Context: Table 1. Example corn yield loss estimates when stress occurs for four or more consecutive days. Adapted from Classen and Shaw, 1970; Rhoads and Bennet, 1990; and Shaw, 1988.  The Corn Development stage known as early vegetative (VE - V12) has an estimated Yield Loss per Day of Stress of 1-3. The Corn Development stage known as Late vegetative (V12 to VT) has an Estimated Yield Loss per Day of Stress of 2-5. The Corn Development stage known as Pollination to Blister (R2) has an Estimated Yield Loss per Day of Stress of 3-9. The Corn Development stage known as Milk (R3) has an Estimated Yield Loss per Day of Stress of 3-6. The Corn Development stage known as Dough (R4) has an Estimated Yield Loss per Day of Stress of 3-5. The Corn Development stage known as Dent (R5) has an Estimated Yield Loss per Day of Stress of 2-4. The Corn Development stage known as Maturity (R6) has an Estimated Yield Loss per Day of Stress of 0.

Question: What is the estimated yield loss per day of stress for corn in the late vegetative development stage?

Answer: 2-5

Iowa State University. (2023). How Drought Affects Corn & Soybean Growth & Yield. https://www.no-tillfarmer.com/articles/12564-how-drought-affects-corn-and-soybean-growth-and-yield


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: What should I do if I am expecting more rainfall after May and early June?

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

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


Context: Late season applications are lowered as crop water use declines with increasing crop maturity. At the dent stage of development, corn water use can be as little as 0.15 inches per day on a 75 degree day. The chance of receiving rainfall increases during this portion of the growing season. Applications of 0.75 inches at the beginning of this period may quickly decline to 0.50 inch as the crop nears black layer or maturity.

Question: Does crop maturity increase or decrease during late season?

Answer: increasing

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: 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 represents the calculation of the annual cost  of ownership?

Answer: DIRTI

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: In some situations, irrigators have equipment that applies water faster than the water can infiltrate into the soil. In these situations, smaller application volumes will reduce the potential for runoff or uneven application to the roots. Sprinklers that provide larger wetted diameters will have less runoff issues. Matching sprinkler performance to field/soil conditions and leaving more crop residue on the soil surface are two methods to reduce potential runoff without increasing evaporative loss from increased number of applications.

Question: What is a method to reduce potential runoff without increasing evaporative loss from an increased number of applications?

Answer: Matching sprinkler performance to field/soil condition

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


Context: Increasing the amount of water that may enter the soil in a given period of time: The total application of water will also affect the fraction of the water that may enter the soil in a given time period. Small pockets and depressions 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 (dammer/dikers) will increase the soils surface holding capacities.

Question: what is the most common factor affecting the amount of water that the soil absorbs?

Answer: The total application of water

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: Liability of impact on neighboring home wells and environment: Michigan 2006 legislation required all large volume water users to meet an environmental protection standard of no resource impact. Rent agreements for irrigated land may define who is responsible for upholding the environmental protection standard and the responsibility of any potential liability.

Question: What does Michigan 2006 legislation require when it comes to environmental standards?

Answer: all large volume water users to meet an environmental protection standard of no resource impact

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 improvements: The addition of irrigation to farmland often requires investment in permanent improvements to the land. The landowner may make these improvements upfront and recoup their investment over time in higher land rent charges. If landowners are not willing to pay for the permanent improvements to the land needed for irrigation, the lessee may advance the cost of the permanent improvements and recover his investment over the period of the contract in the form of a small increase in land rent values. Many lease agreements for irrigated land provide no upfront cost to the landowner but transfer value of permanent improvement paid by the lessee to the landlord over the period of 5 to 10 years. Shorter time frames provide a higher value return to landowner.

Question: Who should pay for permanent improvements to the land needed for irrigation?

Answer: landowners

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: Estimating Annual Irrigation Costs. Annual irrigation cost can be divided into two categories: annual cost of ownership and the annual cost of operation - mainly the cost of energy and labor. The annual cost of ownership is often estimated 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 can provide you with the annual cost of the original investment in equipment and improvements.

Question: The DIRTI formula spreads the annual cost of which investment?

Answer: ownership of an equipment investment over its usable lifespan

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: P.A. 33 of 2006 amended Michigan's Natural Resources Protection Act as part 327 of 451. Changes included:  (c) Requirement for new agricultural withdrawals: Both new wells and surface water withdrawal capable of 100000 gallon per day (70 gpm) are now required to register with Michigan Department of Agriculture prior to beginning to pump. Forms are available at the same locations as the reporting forms. You will need to provide the latitude and longitude for the location, an estimate of expected water use by the month and an estimate of the volume of consumptive use of the water pumped. Since most water pumped for irrigation ultimately goes to the evapotransporation of the crop the consumptive use is estimated to be high or about 90%. Water use for harvest cooling is mostly retuned back to surface or groundwater so the consumptive use is estimated to be low about 5 to 10%.

Question: Where does most water used for harvest cooling go?

Answer: mostly retuned back to surface

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: Question: What is the best way to water container plants? Excerpt: To start a drip system for containers or pots, our complete kits are a great way to start such as model'FM01AS'for 10 pots or the'G77AS'for up to 24 pots. For large containers or raised garden beds our'ML50 kit'is ideal.If you would like to add to an existing system or create your own system that can be easily accomplished by buying our products separately. Our suggestion is to use a combination of 1/4 in. dripline'(microtubing with pre-inserted emitters)'and misters for large containers and individual drippers for small pots. For larger or longer containers use a 1/4 in. dripline. For pots use 1-2 .5 GPH drippers per pot. First, categorize the containers and pots into groups with similar sizes and similar watering needs. It is also advisable to divide containers and pots into groups that are either in full sun or in shaded areas. We have made a list'(pot and basket parts list and installation)'for what we think are the best steps to help you install this type of system. Please be aware that every installation application is different and we cannot make this link perfect for every situation. If you do not find the exact information that pertains to your application,'send as an email'with what you would like to do and we will provide a recommendation.

Question: What kind of drippers should be used for small pots?

Answer: use 1-2 .5 GPH drippers per pot

DIG Corp. (2024). Drip Irrigation FAQ’s. https://www.digcorp.com/drip-irrigation-faqs/


Question: What tells me who is responsible for upholding the environmental protection standard?

Answer: Rent agreements for irrigated land

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: How to Get More Out of Your Irrigation System: (1) Make sure your irrigation application is uniform. There are easy catch can systems available to evaluate the uniformity of the application of your system. Make sure to make the correction.

Question: What can I use to evaluate the uniformity of the application of your system?

Answer: easy catch can systems

Kelley, L. (2009b). Irrigation Fact Sheet #8 - How to Get More from your Irrigation System. https://www.canr.msu.edu/uploads/235/67987/lyndon/HGMIrrSys.pdf


Question: What is the best way to irrigate soil with a high sand fraction?

Answer: a moving sprinkler system

NDSU Agriculture. (2024). Irrigation - Frequently Asked Questions. https://www.ndsu.edu/agriculture/ag-hub/ag-topics/crop-production/irrigation-tiling-drainage/irrigation-frequently-asked-questions


Context: Irrigation Fact Sheet # 2: Instantaneous Rates. The soils infiltration rate is the rate water can enter the soils 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. Estimates for water infiltration rates into soil types, may be found in the "physical and chemical properties of soils" section of the soil survey for your county.

Question: What is the unit of soil infiltration rate?

Answer: minutes per inch

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: Evapotranspiration demand that exceeds soil water supplies will result in yield reductions at any time during the crop life cycle. When plant water uptake by the roots is limited so is nutrient availability, uptake, and transport. Additionally, water stressed plants are more susceptible to insect and disease pathogens and have diminished stem integrity.

Question: When can yield reductions caused by evapotranspiration demand that exceeds soil water supplies occur?

Answer: at any time during the crop life cycle

Licht, M., & Archontoulis, S. (2017). Influence of Drought on Corn and Soybean | Integrated Crop Management. https://crops.extension.iastate.edu/cropnews/2017/07/influence-drought-corn-and-soybean


Context: Question: What is modern irrigation? Excerpt: Modern irrigation generally indicates the use of new improved equipment for carrying out irrigation in the farmlands. The traditional techniques of irrigation were not able to irrigate the entire land, especially in the boundaries and depressions. The modern equipment facilitates enhanced use of resources and reduces the human labour for irrigating the fields. Modern irrigation systems are equipped with timers and sensors to predict and deliver the amount of water required by the crops in the fields. Sprinkler irrigation is an example of modern irrigation method.

Question: What is modern irrigation?

Answer: the use of new improved equipment for carrying out irrigation in the farmlands

AgriFarming. (2023). Frequently Asked Questions about Irrigation (FAQs) | Agri Farming. https://www.agrifarming.in/frequently-asked-questions-about-irrigation-faqs


Context: Crop water use estimates can assist producers in irrigation decision making. A good source of E.T. rate charts for the most commonly irrigated crops is Irrigation Scheduling Checkbook Method from the University of Minnesota. Additional irrigation scheduling information can be found at the MSU irrigation website.

Question: What does the Irrigation Scheduling Checkbook Method from the University of Minnesota tell me?

Answer: A good source of E.T. rate charts for the most commonly irrigated crops

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


Context: Effects on soybean during grain fill Drought effects on soybean are generally not as severe as corn. This is a result of overlapping of development stages. When short-term drought stress results in flower or pod abortion, new flowers and pods will set when conditions improve. During prolonged drought stress, or when the stress occurs during pod set and seed filling stages, the compensatory ability is not as likely to occur. Drought can reduce pod number by up to 20 percent as a result of flower and pod abortion. Seeds per pod and seed size can also be affected by drought stress but to a lesser extent than the number of pods. Drought stress often results in earlier maturity or shortening of the grain filling period resulting in lower seed weights and yields. Soybean yield loss from drought stress is compounded by the lack of nitrogen mineralization and nitrogen fixation. In dry conditions, nodules cease nitrogen fixation because of a lack of soil moisture and lack of carbohydrate supply from the soybean plant. If water deficits are short lived, nodule nitrogen fixation can resume.

Question: Why does drought reduce pod number for soybeans during grain fill?

Answer: flower and pod abortion

Licht, M., & Archontoulis, S. (2017). Influence of Drought on Corn and Soybean | Integrated Crop Management. https://crops.extension.iastate.edu/cropnews/2017/07/influence-drought-corn-and-soybean


Context: (12) Check irrigation tires: Check air pressure in each pivot tire. Refill to 20 pounds or the recommended level. Note tires that were near flat, and return a week later to see if they leaked. Expect tires to lose two or three pounds pressure each year if not re-aired annually.

Question: How long should you wait to check whether the tires are week?

Answer: a week later

Kelley, L. (2017). Irrigation Fact Sheet #15  - Irrigation Inspection and Repair. https://www.canr.msu.edu/uploads/235/67987/factsheets/15_Irriation_Inspection_and_Repair_v2_4.21.17.pdf


Context: (1) Enviroweather: computes daily estimate of potential E.T. and projects E.T. demands for 7 days at each of the 58 strategically located weather stations in Michigan calculating crop E.T. using wind, relative humidity, and net solar radiation in addition to temperature to estimate crop E.T. demands. Pick the station nearest to you, and then click on one of the categories listed near the top of the screen (eg. Field crops, Fruit), then click on Potential Evapotranspiration. For corn and soybeans clicking the Crop ET Estimate button then entering the emergences date allowing tracking crop ET as the crop develops. A free service of Enviroweather Network sends daily reports of ET from the previous 4 days and projected values for the next week by text or E-mail to producers that signed up.

Question: How can one benefit from the Enviroweather Network's free service?

Answer: signed up

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: 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: How much does half an inch of irrigation allow me to wet down sandy loam soil?

Answer: five to six inches

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: As a permanent improvement to the land the irrigation well is owned by landowner and the liability of its potential impact on neighboring home wells is the responsibility of the landlord. The liability of its potential impact to neighboring home wells is a relatively small risk that can be managed by the rental agreement. These situations are uncommon but since the well belongs to the landowner the responsibility of the well also belongs to the landowner. The rental agreement can assign the responsibility of cost to improving neighbor well to the lessee if needed. Statements in rental agreements may require the lessee to manage the irrigation to prevent negative impact to neighboring wells, with the option to make improvements to neighboring wells to solve problem if they arise.

Question: Who owns the irrigation well?

Answer: landowner

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: Table 1. Example corn yield loss estimates when stress occurs for four or more consecutive days. Adapted from Classen and Shaw, 1970; Rhoads and Bennet, 1990; and Shaw, 1988.  The Corn Development stage known as early vegetative (VE - V12) has an estimated Yield Loss per Day of Stress of 1-3. The Corn Development stage known as Late vegetative (V12 to VT) has an Estimated Yield Loss per Day of Stress of 2-5. The Corn Development stage known as Pollination to Blister (R2) has an Estimated Yield Loss per Day of Stress of 3-9. The Corn Development stage known as Milk (R3) has an Estimated Yield Loss per Day of Stress of 3-6. The Corn Development stage known as Dough (R4) has an Estimated Yield Loss per Day of Stress of 3-5. The Corn Development stage known as Dent (R5) has an Estimated Yield Loss per Day of Stress of 2-4. The Corn Development stage known as Maturity (R6) has an Estimated Yield Loss per Day of Stress of 0.

Question: What is the short hand for the early vegetative development stage of corn?

Answer: VE - V12

Iowa State University. (2023). How Drought Affects Corn & Soybean Growth & Yield. https://www.no-tillfarmer.com/articles/12564-how-drought-affects-corn-and-soybean-growth-and-yield


Question: What kinds of plants are more susceptible to insect and disease pathogens and have diminished stem integrity?

Answer: water stressed plants

Licht, M., & Archontoulis, S. (2017). Influence of Drought on Corn and Soybean | Integrated Crop Management. https://crops.extension.iastate.edu/cropnews/2017/07/influence-drought-corn-and-soybean


Context: Permanent improvements. The annual cost of permanent improvements made by lessee should be viewed as additional income above lease rate by landowners. Wells are always the property of the landowner of the land they are constructed on but many of the other items associated with the irrigation system may be recoverable or moved by the lessee at the end of the agreement. For this reason it is important to list the land improvements in their entirety and include the handling of the item at the termination of the agreement. If the improvement left by the lessee are all but the pivot or distribution system the landowner has a clean separation at the end of the agreement period if needed, with less potential problem locating another lessee to irrigate the farm allowing the landowner to recoup the investment in land improvements.

Question: What should the annual cost of permanent improvements made by the lessee be viewed as?

Answer: additional income above lease rate by landowners

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: 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: what should you check before installing to ensure that they are reading properly?

Answer: Watermark sensors

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: 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: what is the alternative to not using data from irrigation scheduling systems to make data-driven informed decisions?

Answer: 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.

Melvin, S. (2023c). 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: For potatoes in the early emergence crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 0.12 inches and the estimated water use during the week of June 19-25, 2023 is 0.85 inches. For potatoes in the vegetative crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 0.15 inches.

Question: what is the estimated water usage for potatoes during the early emergence crop growth stage during the week of June 12-18 in 2023?

Answer: 0.12 inches

Stone, G., & Qiao, X. (2023). Estimated Crop Water Use for June 19-25, 2023 | CropWatch | University of Nebraska–Lincoln. https://cropwatch.unl.edu/2023/estimated-crop-water-use-june-19-25-2023


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 normal to wet years, 2017, 2018, 2019, 31% were ranked good, 13% were fair, 17% were wet late, 12% were wet early, 16% were wet all season, and 12% were very wet all season.

Question: what percentage of Nebraska fields were ranked fair in the normal to wet years of 2017, 2018, and 2019?

Answer: 13%

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 top foot will go above field capacity (30cb) after every irrigation or heavy rain. However, if the second foot gets above 30 cb, it would indicate that over-irrigation is occurring. The data in the chart indicated that the field was this dry on a given day and not how many days the soil was drier than 70 cb. The 70 cb level is equal to about 70% of plant available water (PAW) and stress should not start until below 50% of PAW during the summer and 40% in late August and September. Soil types such as those with high sand or clay content would require different levels other than 30 and 70 cb.

Question: what indicates over irrigation is occurring?

Answer: if the second foot gets above 30 cb

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: 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 considered the variable name for the pivot length?

Answer: R

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: 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 considered wet all season?

Answer: 2%

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: 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 is the largest user of freshwater in Nebraska and worldwide?

Answer: irrigation

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: 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 days to maturity for soybeans in the R7 crop stage, the stage of growth that is known as beginning maturity?

Answer: 0

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: To determine the actual cost, we would recommend the use of the IrrigateCost app. The app, which is available for both Apple and Android products, allows users to input their specific information such as acres irrigated, pumping lift, system PSI, pump and pivot life, and inches applied as well as related costs such as for the well and engine, labor, energy, district fees, and taxes. The app then calculates total irrigation cost as well as total ownership and total operating costs.  It also breaks down costs by irrigation well, pump, gear head, pump base, diesel engine and tank and system and calculates per acre annual cost and per acre-inch annual cost.

Question: what are the categories the IrrigateCost app breaks down costs to calculate per acre annual cost and per acre-inch annual cost?

Answer: irrigation well, pump, gear head, pump base, diesel engine and tank and system

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 was the estimated water usage for potatoes during the vegetative crop growth stage during the week of June 12-18 in 2023?

Answer: 0.15 inches

Stone, G., & Qiao, X. (2023). Estimated Crop Water Use for June 19-25, 2023 | CropWatch | University of Nebraska–Lincoln. https://cropwatch.unl.edu/2023/estimated-crop-water-use-june-19-25-2023


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 days to maturity for corn in the R5 crop stage, the stage of growth that is known as 1/2 milk line - full dent?

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


Question: what specific information does the IrrigateCost app allow users to input in?

Answer: acres irrigated, pumping lift, system PSI, pump and pivot life, and inches applied

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: 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 to recalculate the amount of irrigation needed after irrigation days prior?

Answer: updated soil water readings

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


Context: In general, about one-third of the irrigators in the study on the normal to wet years are doing a good job of applying the correct amount of water to minimize deep percolation of water and nutrients and save pumping costs while producing top yields. The other two-thirds could have saved money and water without lowering yield. In fact, about one-third could have saved a lot! On the other hand, about 60% to 80% are doing a good job during the dry years as shown in Table 1.

Question: generally on the normal to wet years how many irrigators are doing a good job of applying the correct amount of water?

Answer: one-third of the irrigators

Melvin, S. (2023c). 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: For pasture grass in the actively growing crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 1.00 inches and the estimated water use during the week of June 19-25, 2023 is 1.50 inches.

Question: what is the estimated water usage for pasture grasses during the actively growing crop growth stage during the week of June 19-25 in 2023?

Answer: 1.50 inches.

Stone, G., & Qiao, X. (2023). Estimated Crop Water Use for June 19-25, 2023 | CropWatch | University of Nebraska–Lincoln. https://cropwatch.unl.edu/2023/estimated-crop-water-use-june-19-25-2023


Question: what is the approximate water use to maturity for corn in the R5 crop stage, the stage of growth that is known as 13/4 milk line?

Answer: 1.0 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: 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 considered very wet all season?

Answer: 27%

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 method uses a ratio of the length of the center pivot vs. the throw of the end gun. The designed end gun throw and the length of the pivot can be found on the sprinkler chart.

Question: what chart can be used to determine the designed end gun throw and the length of the pivot?

Answer: the sprinkler chart

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 approximate water use to maturity for soybeans in the R6 crop stage, the stage of growth that is known as end of seed elongation?

Answer: 3.5 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 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 days to maturity for grain sorghum in the stage 9 crop stage, the stage of growth that is known as physiological maturity?

Answer: 0

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: In a dry year, aerial imagery can be a useful tool to help identify systematic patterns (i.e., rings) within a field as a result of water stress from poor uniformity. However, in high rainfall areas (i.e., low irrigation requirements) aerial imagery may not be able to visually identify differences in the crop canopy. In these instances, it's recommended that catch cans be used to evaluate application uniformity. Evenly distribute cans of equal size across the system, measure the depth of water applied, and compare to identify areas of nonuniform water application.

Question: what may be difficult to visually identify in high rainfall areas using aerial imagery?

Answer: differences in the crop canopy.

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: 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: what does the early installation of soil moisture sensors make easier?

Answer: to get around the field with the pickup or ATV to install the equipment

Melvin, S. (2023c). 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, VRI is not likely to reduce the consumptive use of water (i.e., evapotranspiration). Producers who are considering whether to invest in VRI technology should carefully consider the potential costs and benefits to determine whether VRI is a good fit for their situation.  Types of VRI equipment systems, prescriptions (the map that tells the pivot how to apply the water), and potential uses are described below.

Question: what is a term used to describe the consumptive use of water?

Answer: evapotranspiration

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: For example, if the standard speed of the electric motor is 1770 rpm and you wanted the motor to run at 1650 rpm, you would adjust the frequency of the electric supply from 60 hertz down to 56 hertz [1650 rpm ' 1770 rpm x 60 hertz].

Question: if the standard speed of the electric motor is 1770 rpm and you want the motor to run at 1650 rpm what would you adjust the frequency of the electric supply from?

Answer: 60 hertz down to 56 hertz [1650 rpm ' 1770 rpm x 60 hertz].

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: The two different speeds can be achieved by a simple setup in the computer pivot panel. The degree of rotation at which the end gun turns on, the program simply slows the speed down and then returns it to the faster speed at the time the end gun turns off. The idea is that we want the pivot to cover a constant number of acres per hour. The key is to know how to calculate the slower speed.

Question: what is the main idea the computer pivot panel program wants to accomplish?

Answer: the pivot to cover a constant number of acres per hour.

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: 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: in what types of regions are secondary aquifers especially important?

Answer: where the High Plains Aquifer and shallow sand gravel deposits are absent

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


Question: what is the approximate water use to maturity for soybeans in the R7 crop stage, the stage of growth that is known as beginning maturity?

Answer: 0.0 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: The Chadron aquifer is the sole source of water to more than 160 wells in the Nebraska panhandle and supplies some of the water to at least 50 additional wells, most of which are near the Perkins-Chase county line.

Question: In addition to the 160 wells that the Chadron aquifer provides water for how many more wells does the aquifer support near the Perkins-Chase county line?

Answer: 50

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 amount of irrigation applied last year or the year before may have very little to do with the amount needed this year. The long-term average of irrigation application depth and timing is relatively meaningless for the decisions producers need to make on any given day in the current growing season. However, without any additional data, all an irrigator can do is put on about the same amount of water as in the past and make slight adjustments if the weather is dry or wet.

Question: Does the amount of irrigation applied in years prior have much indication as to how much irrigation should be applied this year?

Answer: very little to do with the amount needed this year

Melvin, S. (2023c). 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: Table I. Normal water requirements for corn, grain sorghum, soybeans, and dry beans between various stages of growth and maturity in Nebraska. For Dry Beans R5 crop stage, the stage of growth is known as early seed fill, the approximate days to maturity is 35, and the water use to maturity is 7.0 inches. For Dry Beans R6 crop stage, the stage of growth is known as mid-seed fill, the approximate days to maturity is 25, and the water use to maturity is 4.2 inches. For Dry Beans R7 crop stage, the stage of growth is known as beginning maturity, the approximate days to maturity is 15, and the water use to maturity is 2.0 inches. For Dry Beans R8 crop stage, the stage of growth is known as harvest 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 dry Beans R6 crop stage or the stage of growth that is known as mid-seed fill?

Answer: 4.2 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: Percent of fields that became wetter moving from August to Sept. 15. The dry years 2020, '21 and '22 fields are much drier than the other years in the fall.  In the weighted average dry years, 2020, 2021, 2022, 42% of fields with soil in the 15-25 in zone became wetter from August to Sept. 15, 30% of fields with soil in the 25-36 in zone became wetter from August to Sept. 15, and 19% of fields with soil in both zones became wetter moving from August to Sept. 15.

Question: what percentage of fields with soil in the 25-36 inch zone became wetter from August to Sept. 15 in the dry years of 2020, 2021, and 2022?

Answer: 30%

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: 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 0.17?

Answer: 0.73

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: Percent of fields that became wetter moving from August to Sept. 15. The dry years 2020, '21 and '22 fields are much drier than the other years in the fall.  In 2020, 45% of fields with soil in the 15-25 in zone became wetter from August to Sept. 15, 21% of fields with soil in the 25-36 in zone became wetter from August to Sept. 15, and 21% of fields with soil in both zones became wetter moving from August to Sept. 15.

Question: what percentage of fields with soil in the 15-25 inch zone became wetter from August to Sept. 15 in 2020?

Answer: 45%

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: Determine the average rainfall per week for the remaining weeks of crop growth and add it into the prediction of how much water may be needed from irrigation. This number should be recalculated each week until the crop is mature. Use Figures 2 and 3 to determine the average rainfall per week in August and in September for central Buffalo County. The chart shows that, on average, central Buffalo County gets 0.60 inch of rain per week in August and 0.55 inch per week in September. The crop is expected to continue growing for three weeks in August and two weeks in September. Remaining available water at maturity is 5.25 inches. The you subtract the average august rain for three weeks which is 1.80 inches. Then you subtract the average September rain for 2 weeks which is 1.10 inches. This gives us that the water we need after accounting for average rain is 2.35 inches. The chart predicts that if average rainfall is received over the next five weeks, only 2.35 inches of irrigation would be needed to mature the crop.

Question: how long is the crop expected to continue growing in August in central Buffalo County?

Answer: for three weeks

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: For soybeans in the V1 1st Node crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 0.24 inches and the estimated water use during the week of June 19-25, 2023 is 1.30 inches. For soybeans in the V2 2nd Node crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 0.47 inches. For soybeans in the V3 3rd Node crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 0.71 inches.

Question: what was the estimated water usage for soybeans during the V3 third node crop growth stage during the week of June 12-18 in 2023?

Answer: 0.71 inches.

Stone, G., & Qiao, X. (2023). Estimated Crop Water Use for June 19-25, 2023 | CropWatch | University of Nebraska–Lincoln. https://cropwatch.unl.edu/2023/estimated-crop-water-use-june-19-25-2023


Question: what should be added into the prediction of how much water may be needed from irrigation?

Answer: average rainfall per week for the remaining weeks of crop growth

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: These six categories were determined because the soil water level where deep percolation losses of water and nutrients slows to a low rate in a silt loam soil is about 70 cb; thus, it is recommended to keep at least one of the sensors in the second or third foot in this range or dryer. Yield losses would not be expected until all the sensors were approaching 140 cb, making the 70 cb level very achievable without any chance of causing yield loss. Field capacity in a silt loam is about 30 cb, so the goal is not to refill the soil above this level with irrigation in the second or third foot.

Question: what is the field capacity in silt loam soils?

Answer: 30 cb,

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 description of a static VRI irrigation prescription is that this prescription stays the same or changes only a few times during the season. Considerations include that it is relatively simple to apply. Does not account for change in spatial variability over a season. Example uses include avoiding irrigation on uncrossed areas, mining differences in soil available water capacity, and variable rate chemigation.

Question: what are example uses for static VRI irrigation prescriptions?

Answer: avoiding irrigation on uncrossed areas, mining differences in soil available water capacity, and variable rate chemigation

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 analysis focused on dividing the fields into one of six categories based on the soil water levels in the heart of the season (July and August) and on Sept. 15. The six categories were developed based on the readings from the Watermark sensors. The sensors generate data reported in centibars and have a range from 0 (wet) to 240 (dryer) centibars (cb). Centibar is a unit of measure that refers to the force required by the plant to pull the water out of the soil and into the plant. Typically, installations use a set of three sensors, with one sensor installed at six to 12 inches, one at 18-24 inches, and one at 30-36 inches.

Question: if three sensors are typically installed how deep is the third sensor?

Answer: 30-36 inches

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


Question: what is the approximate water use to maturity for dry Beans R7 crop stage or the stage of growth that is known as beginning maturity?

Answer: 2.0

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: Percent of fields that became wetter moving from August to Sept. 15. The dry years 2020, '21 and '22 fields are much drier than the other years in the fall.  In 2021, 44% of fields with soil in the 15-25 in zone became wetter from August to Sept. 15, 48% of fields with soil in the 25-36 in zone became wetter from August to Sept. 15, and 37% of fields with soil in both zones became wetter moving from August to Sept. 15.

Question: what percentage of fields with soil in the 15-25 inch zone became wetter from August to Sept. 15 in 2021?

Answer: 44%

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: 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 days to maturity for corn in the R2 crop stage, the stage of growth that is known as blister?

Answer: 45,

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: Knowing approximately, how much plant available water is remaining in the active root zone is critical for calculating the last few irrigations and will be referred to as the "remaining available water." The best method for determining the amount of remaining soil water is to use a soil water monitoring system.

Question: what is referred to as the remaining available water?

Answer: how much plant available water is remaining in the active root zone

Melvin, S. (2019). Scheduling the Last Irrigations in a Year with Delayed Crop Maturity | CropWatch | University of Nebraska–Lincoln. https://cropwatch.unl.edu/2019/scheduling-last-irrigations


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 days to maturity for soybeans in the R6.5 crop stage, the stage of growth that is known as leaves begin to yellow?

Answer: 10

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: To illustrate this, let's look at some data from the Upper Big Blue NRD. The NRD requires growers in six areas that have an increased median nitrate-nitrogen level in the groundwater, to use soil water monitoring equipment in one irrigated field and report the data collected annually. Most of the producers impacted by this rule use Watermark sensors that measure soil matric potential; thus, this study has largely focused on Watermark data for easy comparison. The soils in the NRD are mostly a silt loam or similar soil texture, making the field-to-field data comparable as well. The assumption was made that the farmers using Watermark sensors would represent all irrigators in the area. To protect privacy, the NRD removes names from the information prior to group analysis; therefore, the location for each field is an unspecified area in the Upper Big Blue NRD.

Question: what do most growers impacted by the NRD rule use to measure soil matric potentials?

Answer: Watermark sensors

Melvin, S. (2023c). 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: Soil Sensor Install Tips: As plants mature, later installation can lead to poorer readings as a result of root damage, residual water in the sensor or slurry, and more challenging installation given soil conditions. Because of these disadvantages, early installation of sensors is highly recommended.

Question: what time is highly recommended for the installation of soil sensors?

Answer: early installation of sensors

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: 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 days to maturity for grain sorghum in the stage 6 crop stage, the stage of growth that is known as half bloom?

Answer: 34

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: 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: what type of irrigators may want to decide on their last irrigation date soon than others due to the higher application amounts with flood?

Answer: Furrow irrigators

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


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 ranked good?

Answer: 57%

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: The Brule sand-sandstone aquifer and the Upper Cretaceous aquifer are the other two secondary aquifers in western Nebraska. The Brule sand-sandstone aquifer is distinguished from wells installed in Brule siltstone.

Question: how is the Brule-sandstone aquifer distinguished?

Answer: from wells installed in Brule siltstone

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


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 normal to wet years, 2017, 2018, 2019, 31% were ranked good, 13% were fair, 17% were wet late, 12% were wet early, 16% were wet all season, and 12% were very wet all season.

Question: what percentage of Nebraska fields were wet early in the normal to wet years of 2017, 2018, and 2019?

Answer: 12%

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: Using the 40% recommendation, the data shows many irrigators are applying more water late in the season than is needed. Some years, a significant rain can cause the soil to be wetter in September, but it is usually due to applying more irrigation water than needed. The data shows that in 2017, 72% of fields were over-irrigated late in the season, and even in the drought year of 2022, 36% of fields were over-irrigated late in the year.

Question: what percentage of fields were over irrigated late in the season in 2017?

Answer: 72%

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


Context: Additionally, we need to factor in the cost to pump the irrigation water and the danger of leaching nitrogen and sulfur below the root zone, so irrigation can get expensive very quickly. One inch of water that moves below the root zone, whether from rain or irrigation, will take at least five to 10 lbs. of nitrogen with it. This illustrates that putting nitrogen fertilizer on closer to when the plant will use it with a sidedress application or through chemigation should be considered a best management practice.

Question: what should putting nitrogen fertilizer on closer to when the plant will use it with a sidedress application or through chemigation be considered?

Answer: best management practice

Melvin, S. (2023c). 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: 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 does the dripper on the pump do?

Answer: get the line shaft bearings lubed

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: 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 will suffer greatly if your sprinkler package is out of date?

Answer: Uniformity of water application

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: 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: what is very expensive and is something an irrigator should avoid doing?

Answer: 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: For alfalfa in the stage 4 crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 1.22 inches and the estimated water use during the week of June 19-25, 2023 is 2.05 inches. For alfalfa in the maturity crop growth stage the estimated water use during the previous week of June 12-18, 2023 is 1.30 inches. For alfalfa in the full cover 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 alfalfa during the maturity crop growth stage during the week of June 12-18 in 2023?

Answer: 1.30 inches

Stone, G., & Qiao, X. (2023). Estimated Crop Water Use for June 19-25, 2023 | CropWatch | University of Nebraska–Lincoln. https://cropwatch.unl.edu/2023/estimated-crop-water-use-june-19-25-2023


Question: what is the approximate water use to maturity for grain sorghum in the stage 9 crop stage, the stage of growth that is known as physiological maturity?

Answer: 0.0 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: Many irrigators already use soil water monitoring equipment or ET data to make good data-driven decisions. The only thing they need to do is continue what is working and hone their analysis skills.

Question: what do many irrigators already use to make good data-driven decisions?

Answer: soil water monitoring equipment or ET data

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