Category Archives: Ag Issues
My Nitrogen Challenge
My Challenge: This article was born from numerous conversations. I know reactions will differ; please hear me out. Last week I issued a challenge at the end of my blog post and in my weekly email. The challenge is to everyone with irrigated ground who applies fall anhydrous or spring pre-plant fertilizer:
- Leave 1 piece of ground with a base rate of 70-100 lb N/ac
- Goal is to apply the rest of N in season using a tool like Sentinel Fertigation that senses what the plant needs. I will share 2023 research results from area producers this winter. If you decide you don’t wish to try a tool like Sentinel Fertigation, you can apply the rest of N the way you’d like.
- Only asking to consider for 1 field. Are you willing to join me in this?
My Why: Pre-plant fertilizer is being applied now in fields, so wanted to share for consideration now. Every time negative news is published about the problem of nitrates in our State, I hear about it. Farmers are frustrated and seek to know how to respond. I can also appreciate the frustration. There’s agreement that not everyone in all occupations always do the right thing. There’s concern about increasing nitrates in various wells throughout the State. The other side – of all the farmers trying to do the right thing – isn’t also shared. Many of these farmers genuinely want to leave the land and water better for future generations. The legacy issue is often not mentioned in news articles. More data around soil nitrates in the upper 20 feet of soil profiles is needed to know the impact of current practices. Negative press builds cases for increased regulation. Conversations are occurring. I continue to hear most would prefer figuring out something locally than for regs to come from the state or nationally.
Since last winter, I’ve brainstormed on the nitrate topic with various commodity groups, farmer groups, during field/office/phone visits and while riding in combines during harvest. My questions to everyone included, “What is Ag’s Solution?” “What is ag going to propose?” “Instead of the current headlines, what do you want the headlines to say?” …. How would you answer these questions?
Several suggestions have been made. The discussions have been difficult. Part of this is because there’s so many soil types, Agri-eco zones, farming practices in Nebraska for any one solution. And, honestly, another part is that ag is so divided (till/no-till, cover crops or not, etc.), which also frustrates me, because blaming and divisiveness doesn’t allow for uniting around a cause. Often the end conversation response was, “I/we really don’t know what will work or what else to do”.
I’ve shared On-Farm Research results from farmers’ fields in this part of the State on heavier textured soils showing there’s no one solution with nitrification inhibitors, nitrogen application timing, biological products. The most consistent thing I see is an opportunity around reducing nitrogen rates. I’m not saying there’s one solution. My challenge is around what I feel holds the most promise right now for irrigated ag in this area.
We can’t precisely know an amount of nitrogen to recommend for application to land using pre-plant soil tests and/or any nitrogen equation. They’re good tools. But, we don’t know how much irrigation will be applied in season nor how much mineralization will occur due to weather conditions. Soil agronomy needs biology in addition to chemistry and physics. That’s why I’ve been so supportive of the in-season sensing technologies where the plant tells us what it needs based on what is occurring in the soil. Project Sense was a UNL/NRD/Corn Board/USDA research effort using ground rig applications. I think it never took off because I’m unsure any Co-op or company took the idea on as a business. Would still be applicable.
The UNL pivot-based sensing research resulted in the graduate student forming the company I mentioned in my challenge called Sentinel Fertigation. If there’s other companies doing this, please consider them too. We had 5 on-farm research studies with Sentinel Fertigation in 2023 in York, Clay, Polk, and Butler counties where producers tested pie sectors of their nitrogen rate vs. what satellites were saying the plants needed. What I’ve heard is one field never triggered an additional fertilizer app in some sectors. Another field only had 90 lb N/ac total applied in some sectors. I don’t know the yield results yet, so this is a risk I’m taking in issuing this challenge. No technology is perfect; I heard them adjust as challenges occurred. The sheer research base and idea around this technology is what propels me to propose this challenge. This winter we will share the data and allow the producers to share what they liked/didn’t like. You can then decide if you’d like to try it in 2024. This also gives you time to get set up for fertigation. If you decide it’s not for you, apply the remainder of the N in that field however you’d like.
My goal is not to promote a company but an idea that makes the most sense to me of anything we’re trying. It’s the idea of a base rate and then allowing the plant to tell us what it actually needs based on the growing season it encounters. This could potentially lead to reduced nitrogen rates applied. There’s so much in ag we have to react to. Applying N in-season is also reactive. However, we can also be proactive in showing that farmers and agronomists locally want to keep looking for solutions by trying newer tools/technologies to see any impacts. Please contact me if you are willing to join me in this challenge.
For more info. I shared the Sentinel Fertigation research info. last winter here: https://jenreesources.com/2023/02/26/sensor-based-n-fertigation/
Was wonderful to get away for a couple days to hike in the mountains. Beautiful this time of year too!
JenREES 9/26/22
Atrazine Comment Period: I’m blessed to work with both conventional and organic farmers and learn from them on various tools used in their operations to combat pests. For conventional farmers, one tool that’s been available for over 60 years is atrazine, which is used for weed control on over 2/3 of U.S. corn and sorghum acres. In listening to farmers, this latest atrazine comment period has been confusing, because EPA just re-registered atrazine for use in Sept. 2020 and confirmed the decision to use 15 parts per billion (ppb) aquatic level of concern. This level was based on a large amount of peer-reviewed scientific research and documentation which were in consensus that that 15 ppb level of concern was considered safe for aquatic environments.
The confusing part to those who were sharing was ‘why this change if it was recently re-registered?’. In Aug. 2021, EPA reopened the decision in response to a court case and published proposed revisions in 2022 which would lower the aquatic level of concern to 3.4 ppb. Re-opening a previously confirmed decision in such a short time-frame doesn’t typically occur. The proposed 3.4 ppb level of concern also doesn’t agree with the large body of scientific evidence that was reviewed to make the 2020 decision. It calls into question the scientific validity of this proposed ruling.
In the proposed ruling, in order to apply atrazine, mitigation strategies would need adopting by farmers based on land quality. Some of these listed include: No pre-emergence applications; Atrazine application prohibited when soils are saturated; Atrazine application prohibited when rain is forecasted during application or for 48 hours after application; Aerial application prohibited; Application rate reduced to 2.0 lbs of atrazine on sorghum, field corn and sweet corn in a year; Inclusion of a picklist to mitigate runoff and leaching based on factors of the field (soil, crop, slope, weather, etc.) and predicted atrazine contamination in watershed field is located in; and Record-keeping requirements. The docket of EPA’s proposed revisions is available on Regulations.gov.
The public comment period to these proposed revisions ends on October 7, 2022. The public comment period allows for anyone to provide their feedback on the changes to inform the EPA of knowledge gaps, considerations or concerns that the public would like addressed.
The following are some suggestions before making any public comments on any topics one feels strongly about: Define your objectives for the comment at the beginning; Use specific situations to strengthen your points; Include positive and negative feedback; Use precise and respectful language to state your concerns, identified gaps of knowledge, or additional considerations; Avoid grammatical errors and spelling errors; Include scientific data when applicable; Avoid opinions or undocumented observations; Use an active voice, not passive; Include solutions or specific changes to the language of the docket; Read the docket fully before writing a comment; and Avoid wordy sentences or dense text blocks.
National Corn Growers Association has a prewritten template that can be viewed on its website, and for those who wish to submit a comment through the group, see the following site: https://ncga.com/take-action/become-an-advocate/take-action.
Beef Quality Assurance (BQA) and BQA transport training will be held Oct. 5th from 10 a.m.-Noon at the Fairgrounds in Geneva. You can RSVP at https://bqa.unl.edu/training-events.
Crop Insurance Workshop will be held Oct. 19 at the Heartland Event Center in Grand Island. Register at: https://cvent.me/R5qeL3 or 402-472-4923.
Central Nebraska Regenerative Ag Conference featuring Gabe Brown will be held Nov. 18 at the Tassel Performing Arts Center in Holdrege, NE from 1-4:30 p.m. Pre-register at: 308-995-8133.
Dr. Kohl will be at Farmers and Ranchers College in Bruning at the Opera House on Dec. 8th.
JenREES 5/8/22
Alfalfa Weevil should be scouted in alfalfa now. I have sweep nets that can be borrowed from the Extension office if you’d like. Otherwise, just go to different spots in the field and look for small holes on the newest leaflets near the stem tips. The larvae are small, green, and have black heads with a white stripe down the back. During the heat of the day, they’re often found near the crowns of plants and they curl into a C-shape when touched. To determine economic threshold, cut 10 alfalfa stems at ground level and shake the larvae off the stems by beating them off the sides into a bucket. The economic threshold right now is right around 1.5-2 larvae per stem. More info. here: https://go.unl.edu/tpkz.
K-Junction Public Forum: I’m grateful for the opportunity that EDF Renewables is allowing for a public forum in addition to their second open house regarding the proposed solar farm this Wednesday, May 11 from 6:30-8:30 p.m. at Stone Creek in McCool Junction. Because we’re to be impartial as Extension faculty, I was asked to serve as the moderator for the evening. I just wanted to share a little about this, and also felt it was important to share how I’m choosing to moderate the event so it’s not a surprise that evening.
As I’ve listened to various conversations and perspectives, it just seems like people need the opportunity to share their viewpoints publicly and ask their questions so all can hear the same answers provided. Because of this, a few of us expressed concern to EDF to allow for a public forum. EDF chose to change the open house format to a blended one of both display boards and the forum and I’m grateful for that. While public forums are difficult, I feel there can be some healing that occurs in just being heard, despite differences of opinion, and that’s my hope and prayer.
As I’ve tried to put myself in the shoes of landowners, while my family doesn’t own land in the area of the proposed solar farm, if we were in this situation, our decision would be based on our specific goals and plans for our farm. But our goals may not be the same as our neighbors. Thus, each landowner has to make decisions based on the goals and values that fits his/her family’s specific situation. The difficulty can be for those caught in the middle who don’t get to make that choice, such as neighbors, community members, and those whose jobs also support agriculture in some way.
As I’ve listened, the theme I continue to hear and sense, is the lack of information for a few years that occurred. I think that’s the greater underlying frustration. I’ll admit, that was a frustration to me as I felt I let landowners down by not knowing, thus didn’t have resources available for them to make informed decisions and to help with negotiating contracts. But I had to move past that to what I could do now. While hard, we can’t change the past. We can choose how we face the present and future doing our best to listen to each other and get answers to the questions we have. This public forum will hopefully allow an opportunity to do this. I think it also helps to remember we’re all just people. Regardless of which side a person is on, the person is not the enemy.
Rural Nebraskans are known for being respectful. I watched that during the first open house when differences of perspective were expressed in conversations. I only saw respectful conversation and discourse in addition to the passion for one’s position/perspectives. That’s what I would ask for this Wednesday evening as well.
In the public forum, there will be opportunity for sharing via a microphone and, for those who prefer not to speak, also via written questions. Each person will be given 3 minutes to speak followed by 3 minutes for EDF representatives to respond. I will make every attempt to get to everyone’s questions in the time we have. While it may be hard not to ask follow-up questions, I’m going to ask that everyone who desires has the opportunity to speak before anyone speaks twice. There will be additional opportunities to speak with EDF representatives following the public forum.
3/13/22
Vegetative Management Considerations: This week’s article is co-written by John Hay, Extension Energy Educator and myself. Vegetative management is an important part of solar. The land below the solar panels will need to be maintained in some way. Lately, more people are looking at ways to complement vegetative management with solar to ease the land use conflict and bring more value to the land beneath solar production.
We asked several questions of the EDF Renewable representatives the night of the public informational forum. The plan from them for the time being appeared to be focused on mowing the grass below the solar panels. There seemed to be some openness to learning more about options beyond mowed grass. From the EDF K-Junction FAQ site, there is a link to a news article explaining how solar, cattle, and crops can work together: https://www.edf-re.com/project/k-junction-solar/faq/.
Regardless of what the vegetation is, should the project go through, someone will need to manage the vegetation. We were told that often 5-6 outside contractors are hired. We suggested should some local people currently be interested in this, it could provide an opportunity for them to obtain additional income or off-set a very small portion of the income lost in the ag community beyond landowners.
Grazing Options: The reality of cattle grazing is not good with solar unless the panels are elevated to a height of at least 7’ and conduit is buried underground. Sheep and free-range chickens could be options. We currently don’t have that scale of sheep/free-range chicken production in the County area. It potentially could be another income source should the project go through and a few choose to pursue this. There is an American Solar Grazing Association which is member-driven and members ask questions, conduct research, and share questions/answers with each other: https://solargrazing.org/.
Agrivoltaics is the growing of harvestable crops below the solar panels. The crops wouldn’t include traditional corn and soybeans. They could include different grasses for grazing, alfalfa, and small equipment haying (depending on panel height and spacing). They could include pollinator species. Small acres (1-10 acres or so per quarter) could include specialty crops such as hops, grapes, vegetables, fruits, woody florals. For those situations, it would entail elevating the solar panels. There’s been some research on incorporating different types of vegetable and flower production in how the plants are arranged for dealing with sun/shade at different times of the day. This resource shares more about agrivoltaics: https://www.youtube.com/watch?v=F7mN1ks0hyUneed.
Wells: There’s been a number of concerns about the wells on these irrigated pieces of land. Specific questions regarding this can be directed to the NRD. Grazing and/or use for harvestable crops under the solar array could necessitate a well.
Vegetative Screenings are the use of plants as a screen to obstruct the view of the solar panels. At the public informational meeting, we were told that landowners and neighbors would need to request this. This is something that can be written into contracts.
The above options/considerations require cooperation of the solar developer and may need changes in system design regarding the solar panel height and the ability for people to enter the solar field. Solar farms are fenced and have limited access due to electrical risk. These risks must be addressed before agrivoltaic or grazing options are possible. For vegetative management regarding vegetative screenings, grass or pollinator species, should the project move forward, we’d recommend they be established prior to construction to aid in success of their establishment.
Farm Base Acres: In talking with Kathy Anderson with the State FSA office, it’s hard to know exactly what will happen to base acres depending on how the contracts are written. It’s a possibility of a permanent loss of base acres, ultimately dependent upon how many acres of cropland there is and how many base acres were assigned to each farm. Each situation will be farm by farm. If the farm had full base (80 ac crop ground and 80 ac base), and 60 acres were being used for solar, 60 base acres of solar would be removed from that total leaving 20 base acres. If there isn’t full base (80 ac crop ground and 60 acres of base), the gap of 20 “free acres” would be put towards the acres in solar and the base would be reduced to 20 acres. If the ground was in CRP, contracts with solar are not allowed. Thus, one needs to ask the company to pay back the CRP contract if they want a CRP parcel.
JenREES 3/6/22
Estate Planning Workshop: A reminder of the estate planning workshop to be held on March 8th from 1:30-4 p.m. at Harvest Hall at the Seward Co. Fairgrounds (location changed). Even if you haven’t RSVP, feel free to still attend if you’re interested.
Seward County Ag Banquet: The 54th Annual Kiwanis Club of Seward Ag Recognition Banquet will be held on Monday, March 21 at the Seward County Fairgrounds. A social with wine, cheese, and sausage will be at 5:30 p.m. with prime rib dinner at 6:30 p.m. To reserve seats, call Shelly at 402-643-3636.
Proposed York Co. Solar Farm: I’m grateful for the public informational meeting in McCool Junction that was held by EDF Renewables in February. It’s important that people can gather and share. I’ve been asked about Extension’s role; it’s to listen, provide educational resources, and share perspectives regarding concerns and considerations. Thus, my focus of this week’s article in regards to some perspectives and considerations in relation to contracts. I plan to share on vegetative management and potential economics next week with my colleague, John Hay, Extension Energy Educator.
The big-picture difficulty about solar and wind energy in rural America is the fact that this is ultimately a land-use conflict. It’s a conflict between land used by those who make their livelihoods from farming/grazing/haying the land and land used by those who are looking at a future of renewable energy. The conflict also involves the changing landscape. With wind, the large turbines and blinking lights can be seen from a distance in addition to seen/heard by those living around them. On the land use side, 1-2 acres of land per turbine and access road is removed allowing the remaining land to be farmed. With utility scale solar, it’s not vertically visual from a distance, but changes the landscape for those who live around it. On the land use side, for a proposed 5000 acre utility scale solar farm such as this York Co. one, all 5000 acres would be taken out of typical farming production. The challenge with land-use conflicts is determining if the varying viewpoints can come together in some way or not as families, neighbors, and communities are all impacted.
As I’ve listened, the discussion isn’t so much about solar in general, but the size/scope of this proposed project and potential impacts locally. For perspective, the solar farm on the north side of the interstate west of Lincoln is 30 acres. It is a single-axis system, meaning the panels rotate as the sun changes direction during the day, similar in concept to what is proposed. The display board images at the informational meeting showed fixed axis systems not representative of what is being proposed.
Contracts: Some have chosen to sign contracts as it provided a consistent payment, provided a way to keep land in a family when there isn’t an heir to work the land, or for other personal reasons. Some have chosen not to sign because the land is their livelihood, they’re concerned about the future impacts to other aspects of the ag and local economies, or for other personal reasons. It’s important to remember there’s not necessarily a right or wrong for ‘why or why not’ regarding signing contracts, and the ‘why’ for each is based on individual/family goals and values. However, there definitely are things that need to be considered prior to signing these long-term contracts in order to ensure a fair contract and protection for the landowner.
First, for those on the fence, while you most likely feel pressure from both sides, your decision needs to be based on what aligns with your goals and values. Take the time to review and negotiate these contracts and always know that saying “no” is an option. We recommend you have an attorney who specializes in wind/solar energy review the contact. Extension has recommendations from who we’ve worked with if you’re interested. Specifically, these contracts need to include: liability, indemnification (should be insured under the company), list a maximum percent drop of acres, decommissioning, and consider adding “most favored nation” to contracts to allow for the best payment and terms. There’s vegetative management things I’ll cover next week. A group of landowners can work together with an attorney to negotiate the best contract with a company; for example, landowners within the Saline Co. windfarm did this.
Resources: This resource contains a checklist of items for contracts to discuss with the company and an attorney: https://farmoffice.osu.edu/sites/aglaw/files/site-library/Farmland_Owner%27s_Guide_to_Solar_Leasing.pdf. John Hay’s website contains more information on solar lease considerations for landowners: https://go.unl.edu/2xch. The following resource is a webinar recording on land use conflicts-wind/solar: https://uada.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=b2d87be8-6d94-48e3-a8c7-ae220131e443.
Ambiguous Loss & Farming — Views from VanDeWalle
Sharing this post from my colleague Brandy VanDeWalle with Fillmore County Extension. You can read the remainder of it by clicking on the link to her blog below.
Picture this scenario. A young farmer in his thirties is looking forward to taking over the family farm someday. Suddenly the father is impacted by a life-changing health incident that leaves him mentally incapacitated and unable to explain the workings of the farm or other advice for the son. Or… imagine being the wife who […]
Ambiguous Loss & Farming — Views from VanDeWalle
Considerations for Leasing Land for Solar Development
Leasing land for solar development is a topic landowners in the McCool Junction and Lushton area are facing. This is a guest column by my colleague John Hay, Nebraska Extension Energy Educator.
Renewable energy has increased significantly in recent years and the number of wind farms and size of wind turbines are a visual reminder of renewable development. Due to higher development cost, solar electric systems, also called solar photovoltaic (PV), have lagged in commercial electric development. In recent years, the dramatic price decline of solar PV has led to greater interest in utility scale solar development. For instance, consider a 5-Megawatt system similar to the one constructed West of Lincoln North of I-80. Based on solar cost benchmarks published by the National Renewable Energy Lab, a 5-Megawatt system constructed in 2010 would have cost $27.6 million dollars, compared to $5.65 million dollars to construct the same size project in 2018. Combine this with the 26% federal tax credit and the economics of utility scale solar are sufficient for major development interest across the nation. The federal tax credit is currently 26% and set to decline to 22% in 2021, then 10% for future years.
Utility scale solar farms are constructed on open ground generally near access to the electric transmission grid. Other considerations for siting solar farms may be the solar resource, proximity to electricity demand, other local incentives, and regional value of electricity. Access to land is an early step in utility scale solar development. Farmers and landowners in Nebraska are being approached to lease land for solar development and these landowners are facing important long-term decisions about the future of their land. When considering a solar leasing contract many factors should be considered. According to the Farmland Owner’s Guide to Solar Leasing published by the National Agricultural Law Center these considers are: Length of the commitment, Who has legal interests in the land?, Impacts on the farm and land, Family matters, Property taxes, Government programs, Liability and insurance, and Neighbor and community relations.
Utility solar farmland leases are long term contracts and need to be reviewed by a qualified attorney. In Nebraska these leases can be as many as 40 years and longer if extended. For many landowners this long-term contract may extend into the next generation and should be discussed with family. Landowners at times feel pressure to sign contracts and this can be stressful. Take the time to review and negotiate these contracts and always know that saying “no” is an option.
Solar leases can be attractive to landowners as they can offer long term income and profitability on the leased land. A study in Michigan of landowners with wind farm leases showed farmers with leases invested more in their farms than farmers without leases. This suggest the lease income may influence farm stability and longevity. Solar farms like wind farms add to county tax income. These developments are exempt from property tax and instead have a nameplate capacity tax paid each year in place of the property tax.
Utility scale solar farms are unlike wind farms in some ways. For example, wind turbines may take only 1-2 acres out of production per turbine because farmers can farm around the base of the turbine and turbine access road. In comparison, a 1,000 acre solar farm will take all 1,000 acres out of production. Solar farms are low to the ground and have less impact on the skyline. Generally solar farms will be fenced with vegetation growing amongst the solar panels. Vegetation could be perennial pollinators, grass, or weeds. Common management is periodic mowing to ensure plants do not disrupt solar operation and production.
Landowners approached about solar leases should seek advice from an attorney and take time to thoroughly consider the contract and its implications to their farmland. Review of the Farmland Owner’s Guide to Solar Leasing published by the National Agricultural Law Center will help frame the issues and considerations for solar leases. This can be found at: https://farmoffice.osu.edu/sites/aglaw/files/site-library/Farmland_Owner’s_Guide_to_Solar_Leasing.pdf. For additional questions about solar leasing, please see https://cropwatch.unl.edu/bioenergy/utility-scale-solar, or contact John Hay, Extension Educator at 402-472-0408 or jhay2@unl.edu.
Coping with Stress During a Crisis
Good resources for managing stress during a crisis.
With the flooding and blizzard conditions affecting a large portion of the state, this week I looked up some Extension resources and decided to write some of the research ideas for dealing with stress and how to help the whole family cope. First of all, our Nebraska Extension publication, Effective Management of Stress & Crisis points out numerous tips that come from worldwide research on strong families. It involves research from more than 24,000 family members in 35 countries. While the publication identifies 18 ideas, I selected the top ten that interest me. For the remainder of the ideas, go online to the publication which can be accessed through our extension.unl.edu website and search for “Effective Management of Stress & Crisis.”
Photo by Pedro Figueras on Pexels.com
Ideas for coping with stress and crisis include:
- Look for something positive to focus and focus on that positive element in…
View original post 388 more words
Long-Term Irrigation Water Requirements for Corn in the Little Blue Natural Resources District Counties
Irmak S-Newsletter Article LBNRD-Final (PDF version of this article)
Authored by:
Suat Irmak
University of Nebraska–Lincoln
239 L. W. Chase Hall, P.O. Box 830726, Lincoln, NE 68583-0726
E-mail: sirmak2@unl.edu Ph: (402) 472-4865
http://engineering.unl.edu/bse/faculty/suat-irmak-0/|
(Author’s note) The scientific and research-based data and their interpretation presented in this article is intended solely for informational purposes and should not be interpreted otherwise in any shape or form. As a University faculty member, the author cannot and will not take sides with respect to water resources allocation decisions. Thus, the author is not for or against any potential water allocation. The author sees his role as an unbiased university faculty member is to share information and data with all people we serve to aid in making better-informed decisions. The following information was presented to the Little Blue Natural Resources District Board by the author on December 6, 2016.
Water allocations may occur in areas where long- or short-term rate of depletion of water resources exceeds water availability. Availability (decline or increase) of water resources can be impacted by numerous natural and human factors, including:
- Overpumping of surface and/or groundwater resources due to suboptimal irrigation management that result in over-irrigation [optimal irrigation management is considered as using one of the or a combination of the technologies available (soil-based, climate-based, or plant-based) to determine the proper irrigation timing and amount to meet crop water requirements for optimum crop growth and yield],
- Change in climatic variables, including air temperature, precipitation, solar radiation, wind speed, vapor pressure deficit,
- Soil physical properties,
- Potential changes in crop water use as a result of changes in climatic and other hydrologic variables,
- Changes in growing season length,
- Cropping patterns, including changes in crop hybrids, varieties, and cultivars, and switching from agricultural lands to natural land use (e.g., grasslands) and vice versa,
- Irrigation methods used as well as irrigation management practiced,
- Soil and crop management practices,
- Geologic conditions, including elevation,
- Other factors.
Thus, when water allocation programs are planned, the aforementioned factors should be taken into account to develop and implement a reasonable, but effective, allocation program. Discussions have been occurring in the Little Blue Natural Resources District (LBNRD) in terms of potential water allocations. In this article, long-term (30 years) data are presented to evaluate the impact(s) of various water allocation amounts in terms of meeting (or not meeting) crop water requirements for one of the major agronomic row crops produced in the district (corn). The counties considered in the analyses are: Adams, Clay, Jefferson, Thayer, Webster, Nuckolls, and Fillmore. Dr. Irmak has been conducting numerous scientific research projects in this part of the state for corn, soybean, sorghum, winter wheat, sweet corn, seed corn, and other cropping systems since 2003. Some of the major research topics include, but are not limited to: soil-water resources and irrigation engineering; crop water use efficiency; variable rate irrigation and fertigation; agricultural water management and conservation; measurement and modeling of surface energy balance, evapotranspiration, transpiration, evaporation and water productivity of agro-ecosystems; spatio-temporal plant water extraction; agro-meteorology; impact of change in climate variables on water resources and agro-ecosystem productivity; impact of tillage practices on water and energy balance; cover crop impact on soil quality and water and energy balance; measurement and modeling of soil moisture dynamics and soil physical properties.
Using long-term climate and crop water production functions that have been measured in Dr. Irmak’s research fields, crop water requirements were calculated for each growing season from 1986 to 2015 for corn. Detailed procedures are presented in refereed scientific journal articles published by Dr. Irmak and his research team and all these scientific publications are available.
Precipitation Trends
One of the critical variables that impact water availability and water balance components in any given area is precipitation. The growing season total precipitation amounts from 1986 to 2015 for seven counties are presented in Figure 1. While it varies with various factors, the growing season in this article was assumed to be from planting in May 1 to physiological maturity in September 30. The growing season precipitation has a fluctuating trend, but overall, there are declining trends in all counties. The magnitude of decline in precipitation exhibited substantial variation between the counties. The growing season precipitation has declined by 5.58, 6.41, 1.21, 2.68, 4.51, 4.45, and 1.73 inches in Adams, Clay, Jefferson, Thayer, Webster, Nuckolls, and Fillmore County, respectively, from 1986 to 2015. When the average of all counties is considered, the LBNRD has been receiving 3.79 inches of less precipitation in recent years than it did in mid-1980s and early 1990s, which can considerably impact water availability in the area and these changes in precipitation trends as well as magnitudes can substantially impact water balance analyses. It should be noted that the aforementioned magnitudes of trends are calculated from 1986 to 2015 and if a different period was used, the magnitudes and trends may change. However, the important point in Figure 1 is the significant overall decline in precipitation over time.
Gross Irrigation Requirements for Corn
Gross irrigation requirement (GIR) is defined as the amount of water required to be pumped to meet the net crop water requirement in the field. Not all pumped water can make it to the crop root zone due to losses during the water transport and application process. Since some amount of water is lost during this process due to conveyance, distribution, field application, evaporation, canopy interception, leaks, etc. additional amount of water is needed to be pumped to ensure adequate net irrigation requirement in the crop root zone is met. The net irrigation requirement (NIR) is the amount of water that is actually needed in the crop root zone to meet crops’ evaporative demand (evapotranspiration) to maintain adequate growth and development for optimum yield production. The amount of water that needs to be pumped to achieve net irrigation requirement is a function of the efficiency of the irrigation system used and other factors. By definition, the NIR does not include losses that may occur during the transport, distribution, and application of water in the field as opposed to gross irrigation water requirement. Thus, the NIR needs to be adjusted with the irrigation system’s efficiency. It should be noted each irrigation system has a different irrigation efficiency value and this value is not constant, rather it is dynamic and change over time, even in the same growing season as a function of numerous factors, including climatic factors and canopy development. For example, not all center pivots have the same or similar irrigation efficiency value and the values can change significantly depending on numerous factors, including how any given system is managed (in addition to climatic conditions and canopy development). Thus, using accurate irrigation system efficiency value is important for accurate quantification of GIR.
Annual gross irrigation requirements (GIR) of corn for all counties for each year are presented in Figure 2. As expected, GIR varied substantially from year to year as a function of numerous factors that influence crop water use, primarily climatic variables, including precipitation. These GIR values were determined for a healthy center pivot-irrigated corn crop that is actively growing and transpiring water vapor and result in very good grain yield (e.g., 230-250 bu/ac). The GIR values were adjusted by the irrigation efficiency of the center pivot, which is assumed to be 85%. It should be noted that the irrigation efficiency of a center pivot system is not a constant value, and can significantly change with numerous factors, including pivot operation conditions, maintenance, crop growth stage, crop management, and other factors. Thus, even for the same center pivot system, the efficiency value can change over time within the same growing season. Even a well maintained center pivot can have very low irrigation efficiency, depending on the conditions in which the irrigation application is practiced. This is valid for all other irrigation systems, but with different irrigation efficiency values.
Figure 1. Temporal (1986-2015) distribution of growing season precipitation in seven counties in the LBNRD.
The GIR for corn ranged from zero in all counties in 1993 (which was one of the wettest years in Nebraska) to as high as 26.9 inch in 2002 in Webster County (Figure 2e). The GIR values were also very high for all counties in 2012 (about 26 inches). Figure 2 is an example of inter-annual variation in irrigation requirements in that it is different every year. Thus, using an average value for GIR or water allocation programs may not provide a detailed picture of this variation.
For much more effective determinations of adequate GIR for a given county, the standard deviations of the GIR values should be considered. Standard deviation values represent the amount of difference from the mean (average) value. The standard deviation values of long-term average corn GIR for each county is presented in Figure 3. As Figure 3 clearly shows, the long-term average GIR values have very large standard deviations that should be taken into account. The standard deviation of long-term average corn GIR ranged from 5.9 inches in Adams County to as high as 7 inches in Jefferson County with a seven county average value of 6.6 inches. The interpretation of the standard deviation values should also be done very carefully, because it will considerably impact the crop productivity response to an average allocation amount. For example, in Jefferson County, in a given year, the long-term average corn GIR can be as much as 7 inches above the long-term average GIR value, depending on the climatic and other conditions. If this happens in a given year, the crop production and associated farm net income would be significantly jeopardized when the water allocation is determined based on the long-term average value. While it is used in practice very often, when natural systems are considered, there is no such term as “normal” as every year is different when various climatic variables are considered. However, determining the standard deviations and especially determining the allocation amounts based on the standard deviations for multiple counties that have spatial attributes is an extremely difficult task. Therefore, in many applications, long-term values are used instead, perhaps for simplification.
Different Water Allocation Amounts and Meeting the Corn Irrigation Requirements
Different hypothetical amount of water allocation amounts and what percent of the time these amounts are not able to meet corn crop’s GIR in each county are presented in Table 1. In Table 1, the allocation amounts were varied from 7 to 12 inches and the number of years and the percentage (with respect to total number of years from 1986 to 2015, which is 30) when the allocation amount was not able to meet corn GIR were determined. The interpretation of Table is rather very simple. For example, a 7-inch of water allocation was below corn GIR in 17, 17, 14, 17, 22, 21, and 12 years out of 30 years in Adams, Clay, Jefferson, Thayer, Webster, Nuckolls, and Fillmore Counties, respectively. In terms of percentage, a 7-inch water allocation was not enough to meet corn GIR at 56.7, 56.7, 46.7, 56.7, 73.3, 70, and 40% of the time in Adams, Clay, Jefferson, Thayer, Webster, Nuckolls, and Fillmore Counties, respectively. The impact of other allocation amounts (8, 9, 10, 11, and 12 inches) on meeting (or not meeting) corn GIR can be interpreted in the same way in Table 1.
Table 1. Percent of time when different water allocation amounts would not meet corn gross irrigation requirement (GIR).
Figure 2. Temporal distribution of corn gross irrigation requirements (GIR) in seven counties in the LBNRD from 1986 to 2015.
Figure 3. Standard deviation (inch) of gross irrigation requirement (GIR) for corn in seven LBNRD counties. The standard deviation values were calculated for the period from 1986 to 2015.
It is important to note that the analyses for potential impact(s) of various hypothetical water allocation amounts on meeting (or not meeting) corn irrigation water requirement to produce good yields (e.g., 230-250 bu/ac) were carried out for the period from 1986 to 2015 for specific counties in the LBNRD. Analyses, data, and interpretations should not be extrapolated beyond these boundaries.
Information and data provided above are solely for information and education purposes. The author does not take any sides or provide any opinion as to whether allocation should be imposed or not. If the decision is made to go forward with the allocation, some of the most effective water allocation programs are those that incorporate research-based educational and outreach aspects of water management and university can offer technical and scientific aid to growers and others who are involved in crop production and irrigation practices to make the best use of the allocated amount of water resources for optimum crop production. This includes implementation of technology to counter some of the potential negative impact(s) of limited water resources for optimum crop production. There are numerous proven, effective irrigation management strategies, tools, and methods developed at UNL that result in enhanced crop water productivity. This can be achieved by reducing or eliminating over-irrigation and conserving water resources through reducing unnecessary water withdrawal for irrigation. For some of these resources, readers are encouraged to visit the Nebraska Agricultural Water Management Network (NAWMN) website at http://water.unl.edu/cropswater/nawmn. Some of the publications that are related to irrigation science and engineering, evapotranspiration of various cropping systems in each of the NE counties, water management technologies, climate impact(s) on agricultural productivity, and related topics are also listed in Dr. Irmak’s website at https://engineering.unl.edu/bse/faculty/suat-irmak-0/.
RUP Dicamba Training for Soybeans
My top question the past two weeks has been about dicamba training. I just received the information regarding this training from our pesticide program coordinators.
First, to clarify some mis-understandings: Dicamba training is required for those applying the following dicamba products: XtendiMax®, FeXapan™, and Engenia®. These products are all Restricted Use Pesticides (RUP) this year; thus, you have to be a certified applicator to purchase and use these products. Dicamba training is not required if you’re applying dicamba corn products (unless it is the above-mentioned products).
Second, pesticide training of any kind is not the same as dicamba training. Dicamba training is completely separate. Having your pesticide applicator license does not qualify you to apply RUP dicamba in 2018.
Third, some have asked if everyone in the operation needs this training or not…specifically the person who is purchasing the RUP dicamba with his/her applicator license but is not the one intending on applying the chemical. NDA says that, “Dicamba-specific training is only required for application of the product, not for purchase of the product.”
- You need to be a certified pesticide applicator to purchase the RUP dicamba products.
- You need to be a certified pesticide applicator and complete dicamba training to apply the RUP dicamba product. So hopefully that helps clarify who in your operations need this training.
Your options for RUP dicamba training include the following:
- Nebraska Extension online training course hosted by eXtension. See the link at : https://campus.extension.org/login/index.php (1.25-1.5 hours).
- Crop Production Clinics or Nebraska Crop Management Conference. Details at https://agronomy.unl.edu/cpc and https://agronomy.unl.edu/ncmc
- County-hosted training sessions at the option of local educators presenting the video which is the same as the online training (1.25-1.5 hours).
- RUP dicamba product (XtendiMax®, FeXapan™, and Engenia®) manufacturer sponsored training. Each manufacturer will advertise individually.
I took the online training so I could better answer your questions. The link to the UNL online dicamba training can be found at the http://pested.unl.edu site or you can go directly to the training at: https://campus.extension.org/login/index.php. Once at this site, you will need to create an account. You will then be sent a confirmation email and upon opening that, you will be logged in. From the course list choose “pest management”.
Then scroll and click on “Online Training for Dicamba Herbicide”. 
You will then need to register for the training. It will ask you to add your Nebraska pesticide applicator number in a specific field as well. Your name and applicator number are required before you begin the training. You can then click on the first video followed by the first quiz. It keeps track if you completed the entire video or not before you can advance.
I felt the information was good overall and I appreciated the fact that they mentioned how corn dicamba applications also influenced the problems we saw in 2017. They also share quite a bit of research regarding volatility, conditions/timing of temperature inversions, dosage amounts and effects on yield. The quizzes are short and were fairly common sense. You can click to check each answer once you have selected your choice and will have to submit all your answers before moving on. When you have completed all the videos and quizzes, you can have a certificate emailed to you. You will also be officially entered into Nebraska Department of Ag’s database. NDA said they will only honor those names in their database as those who’ve completed dicamba training.
NDA is asking ag retailers selling these RUP dicamba products to check the NDA database to ensure the person applying the product has received dicamba training. NDA’s dicamba information including record keeping forms, etc. can be found at: http://www.nda.nebraska.gov/pesticide/dicamba.html.
The other thing you need to know: some have asked if a group of people can watch the online training at the same time at your farmstead. The answer is actually no from the standpoint you all would have to watch the training on separate computers/devices. The only way your name is recorded in the NDA database is through your registration name and pesticide applicator number on the training site. It only allows one person to enter his/her information to view the training and complete the quizzes. If you attend an NDA approved face-to-face training such as at Crop Production Clinics, you can train as a group but will still need to supply your individual names and pesticide applicator numbers at the training.
Hopefully this helps clarify some of the questions you have and during this cold weather, you have the opportunity to get this training completed if you need it for 2018.
Reminder: York Ag Expo at the Holthus Convention Center in York January 10-11. Schedule of Events and Exhibitors: http://yorkchamber.org/yorkagexpo/
Educational Sessions: https://jenreesources.com/2017/12/26/york-ag-expo-educational-sessions/
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