As I reflect, it was a hard week for many of you in our farming community with the weather and harvest delays. Many of us would say the challenges of 2019 actually started in the fall of 2018. From that perspective, it’s been an extra hard year! As we continue with a delayed harvest, I’m truly hoping the fall of 2019 doesn’t result in an extra challenging 2020 as well. I’m sure that’s a hope for us all!
It’s amazing how something as simple as the sun shining or incredible sunrises on then dreary, drizzly days lifted my spirits and the spirits of many of you I spoke or texted with this past week. For those who receive my email newsletter, you’ve seen me share each week a set of tips to consider for help in relieving stress/changing current mindset based on how much time you have in the day. And, some of you have rightfully put it back on me when I’ve needed a mindset change! While you may not want to take 30 minutes or even 10 minutes, we all have 2 minutes. So, my challenge for all of us is utilize one of the following tips for two minutes or use something else that works for you each day this week to change our mindset/lift our spirits when needed. Two minute tips (Adapted from: Gilbert Parra, PhD; Holly Hatton-Bowers, PhD, and Carrie Gottschalk, LMHP, MS): Breathe; Stretch; Laugh; Doodle; Acknowledge one of your accomplishments; Say no to a new responsibility; Look out the window (or go outside); (adapted) Faith based prayer. Please go to jenreesources.com for the full list.
Soybean Cyst Nematode (SCN) Sampling: With the increase in sudden death syndrome this year, several have asked for soybean cyst nematode sampling bags (as the two diseases are synergistic with each other). Free sampling is via the Nebraska Soybean Board through your soybean checkoff dollars. Sampling bags can be obtained from your local Extension Office or call 402-472-2559 to obtain bags. Crop consultants should contact Extension Plant Pathology directly (402-472-2559) for larger numbers of sample bags. Samples should be done for areas 40 acres or less (less is better). If you had areas with higher SDS this past year or places where yield maps showed lower yields, plan to take a sample from those areas of the field. Also take a sample from a good yielding area of your field for comparison. Take around 20 cores 6 to 8” deep. If you or an agronomist is taking soil samples, taking a few extra cores will allow for part of the sample to be sent in for fertilizer recommendations and the other part for SCN. Make sure to thoroughly mix the cores collected before transferring to sample bags. If you take them from a soybean field, taking the sample a few inches off the old soybean row may provide the highest potential numbers if SCN is present in the field. However, SCN samples can be taken from corn or sorghum fields as well to help inform decisions if rotating to soybean next year. Other places in fields which may first show SCN include: low areas where water drains after rain; along a stream that periodically floods; along fence lines; field entryways or driveways as that’s the first place equipment enters from other fields. Anything that moves soil will move SCN.
Lawn Weed Control: Now is an excellent time for weed control in lawns, especially for dandelions, clover, ground ivy, and plantain. This is because carbohydrates are being transferred to the roots of perennial weeds and thus allows for the chemical to move to the roots as well. If using granular products that contain weed killer, they’re best applied on mornings with heavy dew and no rain in the forecast for 24 hours (however, read the herbicide label). Most herbicides labeled for use around the yard will contain 2,4-D and/or dicamba. I’m often asked for names but this is not an exhaustive list and not intended to exclude anything available (2,4-D, dicamba, Weed B Gon, Trimec Plus, Trimec Classic).
*End of News Column.
- Acknowledge one of your accomplishments
- Say no to a new responsibility
- Look out the window
- (adapted) Faith based prayer
- Listen to music
- Have a cleansing cry
- Chat with a co-worker, friend, or family member
- Sing out loud
- Jot down dreams
- Step outside for fresh air
- Go for a brief walk
- Enjoy a snack or make a cup of coffee/tea
- (adapted) Read faith-based devotional
- Evaluate your day, Write in a journal
- Call a friend
- (adapted) Meditate, Prayer, Devotional
- Tidy your work area
- Assess your self-care
- Draw a picture
- Listen to soothing sounds/music
- Read a magazine
Warm weather with sunshine this time of year prompts a tiny insect looking for final
food before winter to cause a painful bite on humans. I’ve received several questions about “what is that tiny black bug with white marks on back that bites?” The insect, known as the minute pirate bug (and insidious flower bug), is actually a beneficial predator of thrips, mites, aphids, tiny caterpillars, and insect eggs. People will even purchase these insects for biological control, particularly in greenhouse settings. They’re found throughout crop, garden, landscapes, and wooded areas in the summer preying on other insects. However, this time of year they start biting humans they land on. One doesn’t need to worry about them injecting a venom, feeding on blood or transmitting disease. People’s reactions to the bites range from no reaction to swelling like a mosquito bite. Unfortunately there’s also no method of controlling them. Insect repellents don’t work as they aren’t attracted to carbon dioxide like mosquitoes are. They are attracted to light colored clothing, so wearing darker colors and long sleeves can help when being outdoors during warm, sunny days. Otherwise, work outdoors on cool, cloudy days.
Bagworms: This year was a heavy year for bagworms and I’m still receiving calls about treating for them as people find damage. We would recommend it’s too late to treat now as eggs have been laid in most bags at this point and insecticides, including systemic ones, won’t move inside the bags to kill any adults or eggs within the bags. Wherever feasible, you can reduce next season’s load by picking off bags and either squishing them or drowning them in soapy water. Simply throwing them on the ground doesn’t help. I was even finding bags that had dislodged from windbreaks in adjacent crop fields this year with larvae traveling back towards the windbreak! Between 500-1000 eggs can be found in one bag. Aim for insecticide applications next year when larvae hatch and feed, usually at some point in June.
Harvest Thoughts: Several times the topic of palmer amaranth came up this week while in the fields with palmer in patches or especially on field edges. I believe the first step of palmer management begins at harvest by choosing to not run the combine through those patches. Research from the southern U.S. showed 99% of palmer seed survives the combine and we also know the combine is very effective at seed dispersal. Several farmers have shared they could see the worst palmer spreading in their fields the following year where the first combine pass occurred. Research supports this. The highest number of new palmer plants counted in a field were found the successive year where the first combine pass occurred after combining a patch of palmer. So some suggestions to consider: 1-Consider disking or shredding patches of palmer. 2-Plant a small grain like rye or bin-run wheat into endrows and/or patches where palmer was present. Research has shown that burying palmer seed 3-4” and leaving it buried for 3 years can reduce germination 80-100%. I realize disking doesn’t necessarily go that deep and that it’s difficult for no-till guys to want to do any tillage. Shredding won’t kill seed, but it will keep the seed from going through the combine. The small grain will help reduce light interception to the soil surface next spring. That’s the #1 trigger for palmer germination-light penetration on bare soil.
Also, I realize it’s difficult to achieve, yet a reminder to check your beans and harvest as close to 13% as possible. A number of fields last week even with green stems and some leaves remaining on lower plants were actually at 13% when harvested. Delivering soybeans below 13% reduces profits while there’s a dock for delivering wet beans. While not a dock, less than 13% moisture results in fewer bushels to sell (load weight divided by 60 lbs/bu assuming 13% moisture). Selling soybeans at 8% moisture, you’re losing about 5.43% yield; at 9% moisture, it’s 4.4%; at 10% moisture, 3.3%; at 11% moisture, 2.25%; and at 12% moisture, it’s 1.14% yield loss. That doesn’t take into account additional risk for shatter losses during harvest. So another consideration as we consider economics and profitability this year.
Harvest: Grateful to see harvest going last week! There’s a good article in CropWatch from Roger Elmore, Tom Hoegemeyer, and Todd Whitney regarding how cool weather and reduced solar radiation (sunlight) in August impacted yields. Part of our problem with stalk quality is also due to this. Yield potential can be reduced by cool, cloudy weather yet it can also increase grain fill period allowing for heavier ears as we’ve also seen. You can read the article with full details at https://cropwatch.unl.edu. We would also ask for your input regarding the most important weed problems/issues in your part of the State by completing this survey at: https://www.surveymonkey.com/r/QZV8Z2T.
A reminder for all of us to please be safe during harvest! It was sobering scrolling
through Ag Twitter last week seeing the number of people posting pictures of farm accidents. Most common were truck drivers taking corners too quickly, overturning vehicles. It was extra sobering that some of the accidents led to death of family or friends. Others posted remembrances of this time of year when they lost someone due to a farm accident.
For all of us as we’re on the roads,
please be alert and slow down. It’s also important to talk about safety with teens who drive. Gravel roads are especially dangerous with dust blowing as vehicles travel, limiting visibility. Slow down at intersections. On highways, slow down when coming upon slow-moving equipment. And, be aware of equipment turning. Collisions involving 1,432 Ohio farm vehicles and other motor vehicles were analyzed for a four-year period (1989-1992). Seventy-eight percent of two-vehicle collisions occurred during daylight hours, with a peak occurrence during the time interval from 3:00 to 6:00 P.M. Forty-two percent of the nighttime crashes were rear-end collisions, compared to 8% of the daylight crashes. Fifty-two percent of daylight crashes occurred when the tractor operator was making a left-hand turn. It’s hard to know if the drivers behind a tractor will try to pass when you want to make a left-hand turn. To avoid this some will pull off to the right and square up to go straight when they want to make a left-hand turn. I also read an interesting publication from Purdue University called “Learning from Truck and Equipment Collisions”-interesting actual accounts and photos. Bottom line: even if the tractor or truck driver wasn’t at fault, there’s a checklist of items that will be asked as the other party will look for any potential way to place fault. I think it’s a helpful read, especially if you have employees within your farm or ag operation: https://ppp.purdue.edu/wp-content/uploads/2019/07/PPP-127.pdf.
Reading an article on harvest safety by Iowa State University, I was surprised the greatest number of harvest accidents actually involve slipping or falling off equipment. But it makes sense as people are mounting and dismounting tractors and combines several times a day. Painted metal on ladders and platforms can become slippery especially when wet or with factors such as mud, crop residue, snow, or ice. Reminder to use grab bars when mounting or dismounting machinery; wear well-fitting shoes with non-slip soles; and recognize that fatigue, stress, drugs/alcohol, and age can affect stability.
Double check where all people are. Keep children away from machinery and grain bins. Double check to make sure all machinery is working properly and that safety shields are in place. When moving equipment, especially grain augers, watch for power lines, keeping equipment at least ten feet from them. Don’t get into grain wagons or bins while the grain is moving. There’s a new film that every farm family should consider seeing called “Silo” where it talks about the dangers of entering grain bins. This week’s Market Journal highlighted the movie and you can learn more here: https://www.silothefilm.com/. Shut down moving equipment when it gets plugged. It only takes a few extra seconds and is well worth it to save a limb. In the rush of harvest season, our ultimate goal is everyone gets home safely each day/night! Here’s wishing you a safe harvest season!
Crop Update: Thinking about harvest as we continue to watch corn and soybeans progress toward maturity. And as I write this, my desire is to be honest about what I’m seeing and the concerns growers and other agronomists are seeing too. Perhaps part of my perspective is the fact that I’m typically called out to problem situations! But hopefully that perspective helps you in some way know what to watch for in your own fields. So before harvest occurs, would encourage growers to get out in your fields and see for yourself how your crops look. It’s just a great way to estimate what your true harvest potential is prior to harvest. And, it’s always easier to diagnose yield potential problems now vs. post-harvest. There are some tremendous looking fields out there, especially non-irrigated ones! Yet sometimes (once we hit canopy closure) we forget about the early season challenges and the variability that can occur. Variability such as plant stands and plant emergence based on variable seed depth that can be seen now with variable ear sizes. There’s misshapen ears due to various stresses based on specific field practices/situations as well.
The warm, drier weather this week allowed for some noticeable changes. Perhaps the biggest one is the concern regarding tops of corn plants rapidly senescing. This could be due to either anthracnose top dieback or another disorder called ‘top leaf death or dieback in corn‘. Anthracnose can cause leaf lesions, top dieback, or stalk rot. To diagnose if anthracnose is the culprit, you can look for black fungal anthracnose lesions which may be blotchy in appearance on the stalk underneath the leaf sheaths. You can also split the upper or lower stalk looking for any discoloration in the pith or nodes. If you don’t see the lesions or pith/node discoloration, the discoloration in the top of the plant may be due to top leaf death or dieback. A Canadian researcher documented greater top leaf senescence during a period of warm, dry weather during grain fill. Another researcher documented this tends to be more common during good grain fill years. We have experienced that type of weather with a good grain fill period, so top leaf death/dieback may be the bigger culprit.
Yet, be sure to check for stalk rot in these fields. I’m finding stalk rot increasing with each week especially where there’s nitrogen deficiency, areas where water ponded, high plant populations, higher disease pressure, and areas with hail damage. There’s also something interesting happening where in specific hybrids, it appears the refuge in a bag plants are dying early (and have stalk rot) in comparison to the primary hybrid planted (I’m unsure exactly why).
The other thing noticeable this week was husk tissue turning color and ears turning down as hybrids mature. We’ve had a long grain fill period creating large ears with deep kernels. There are specific hybrids where I’m concerned about large ears and small shank diameters. Shanks appear firmly attached for now, but it’s still something to watch. Been recommending growers get those fields out earlier if possible.
To evaluate percent stalk rot, at least 100 plants throughout the field should be assessed. I prefer the ‘pinch test’ and do this by taking my thumb and first finger and pinching the stalk internode that occurs between the lower nodes above the soil line. Do this for 20 plants in an area and get a percentage for those that crush. Then do this for several areas of the field. This YouTube video helps show how to do this: https://www.youtube.com/watch?v=7z75VN1c51Q. Fields that have the greatest percentages of stalk rot prior to harvest may be prioritized over others. Where it worked in their operations, some growers in 2018 chose to harvest at a higher moisture content in order to get at fields in a more timely manner.
Some soybean harvest has started. Taking my final on-farm research notes in fields, I’m noticing dead plants next to green ones. The dead plants often have anthracnose and/or pod and stem blight. In some fields early death is due to sudden death syndrome. Also noticing red/purple leaves on some varieties indicative of cercospora leaf blight. Thus, we have potential for discolored, chalky seed and also purple seed stain again; hopefully nothing to the extent of 2018.
I’m writing this column from our National Agriculture Agents meeting. Tonight was our inspirational service. Our speaker was Marine Corporal Joshua Bleill. He was conducting combat patrols in Fallujah in October of 2006 when his vehicle was struck by an improvised explosive device. He suffered multiple injuries, including the loss of both legs. He shared about his background in ag, learning how to walk again, and the importance of family. He also shared how grateful he was for everything that happened to him for how it grew his faith and made him who he is today. I could relate to gratitude for difficult things in life for how they can shape us. I think many of us have been through difficult things. This year has been especially difficult for many in agriculture. Sharing two things that helped my perspective right now. These things aren’t new, but I needed a reminder. One: Remember the ‘why’ behind what we do every day and keep that fire within us to do our best. Two: Live life so at the end of each day we hopefully made a difference to another person. Again, not new, but good for me to have these reminders when I’m a bit weary right now. Sharing in the event these reminders help you too!
Crop Updates: Grateful for sunshine and some heat last week to help with seed fill and moving along maturity! Seeing some early death and/or compromised stalks in corn plants that are nitrogen deficient, in compacted/formerly ponded areas of fields, or plants with sidewall compaction. I’m not always finding a stalk rot pathogen present right now, but the stalks are compromised and crush easily. So it will be important to continue monitoring fields to assess which should be harvested first. In soybean, sudden death syndrome is causing early maturing and death in some situations. If you’re also seeing pods on plants shriveling up and dying, look for symptoms of pod and stem blight (rows of black dots on the soybean stem). Anthracnose is also present in fields and is indicated by black ‘blotches’ on soybean stems. I have photos on my blog at https://jenreesources.com. There’s nothing to do for either of these right now. Pod and stem blight is part of the Phomopsis/Diaporthe complex that caused dark and chalky looking seed at harvest in 2018. Also note what varieties appear more impacted.
Soybean Quality Research Project: Speaking of seed quality, a study funded by the Nebraska Soybean Board is focusing on influence of water regime (irrigated vs. non-irrigated) on soybean seed quality parameters (seed protein, oil concentration, and test weight). We’re looking for farmers who have BOTH irrigated and non-irrigated fields (dryland field corners don’t count as non-irrigated fields) and asking for help collecting seed samples at harvest time. Plastic jars will be provided to collect samples in each field (at around 25%, 50%, and 75% of the field being harvested). This seems like a lot of sampling, but it’s to help understand any variability of seed quality across fields. If you are interested in helping, please contact myself or your local Extension educator.
Wheat Information: I’ve had a few calls regarding wheat planting. Some have asked about using seed that has scab. Using that seed can greatly reduce the germination and seedling vigor. It’s best to clean the seed and have a fungicide seed treatment applied. I recommend a fungicide seed treatment for all wheat seed regardless if it is bin-run or certified seed. The August 30th UNL CropWatch edition at https://cropwatch.unl.edu has wheat information including seeding rates, disease and insect management, and variety information so be sure to check it out!
Fall Invaders: It’s that time of year for fall invaders such as millipedes, centipedes, crickets, spiders, roly polys, earwigs, and lady beetles. Control fall invaders once they enter the home by vacuuming them. There are home-owner sprays that can be used on the outside perimeters of homes to help reduce the number that enter your home. Sealing any cracks and crevices is another way to help exclude them.
*I’m grateful to Dr. Richard Ferguson, former Extension Soil Fertility Specialist, for reviewing this article; Dr. Charlie Wortmann, Extension Soil Fertility Specialist, for sharing research-based studies with me; and Glen Slater, SCAL Research Technician, for sharing details of the SCAL study mentioned below.
Nitrification Inhibitors: Two weeks ago, my column included a general overview regarding nitrogen losses in addition to general summary statements based on research. Nitrification inhibitors are best thought of as an insurance policy against loss of applied ammonium-based fertilizer due to excess rain in the first month or so after fertilization. Dr. Richard Ferguson, former Extension Soil Fertility Specialist, and his team have conducted much research regarding the use of nitrification inhibitors over time. Much effort has occurred in sandier soils within the Central Platte NRD. However, an ongoing study at UNL’s South Central Ag Lab (SCAL) near Clay Center is conducted on silt loam soils which are more common in the UBBNRD. Twenty-eight years of this study are summarized here. The majority of the study at SCAL compared Spring pre-plant anhydrous vs. side-dress application with and without the use of nitrification inhibitor N-Serve (nitrapyrin). This product was the product available back in the 90’s. The study actually began by comparing 2 different in-season side-dress applications before switching to pre-plant vs. side-dress in the early 2000’s. Soil samples for nitrate and ammonium content were taken when funding was available. In talking with Dr. Charlie Wortmann, UNL Extension Soil Fertility Specialist, he mentioned that they found yield to be correlated to amount of nitrogen in the soil. A yield increase due to nitrapyrin applied pre-plant was observed in 6 of 28 years with a mean yield change of 2 bu/ac/year. Only 1 of 28 years was a yield increase observed when nitrapyrin was applied in season during side-dress application with a mean yield change of 0 bu/ac/year. In this study, they found that delayed side-dress N with nitrapyrin could reduce plant N uptake. A detailed analysis of nitrapyrin effects on N uptake and soil accumulation from early years of this study can be found in Ferguson et. al (1991). The duration of inhibitor efficacy was measured in other studies where it was found a nitrification inhibitor such as nitrapyrin to last around two weeks with Spring applications. They’ve seen it last as little as 1 week to as long as 6 weeks depending on soil temperatures and moisture. The use of inhibitors is not advised in season as research showed they can release N too slowly for the crop demand resulting in yield loss and/or resulting in increased leaching of nitrogen when it was released too late in the growing season for crop uptake. In general, the research is more supportive for nitrification inhibitor use in sandy soils vs. heavier textured soils; yield benefit to a nitrification inhibitor may be none to a few bushels/acre for silt loam or silty clay loam soils.
In-Season Applications of Nitrogen: In-season application means the nitrogen is applied when the crop is actively growing and utilizing it, greatly reducing potential for loss. Recent on-farm research studies compared side-dress applications using either the UNL equation/Maize N model or industry models such as Climate Field View. In all these studies, the recommended rate was compared to rates that were at least 30 pounds over and under the recommended rate. Some of the studies went as high as +/- 50 lbs/acre compared to recommended rate. I’ve compiled these results in a table at https://jenreesources.com/2019/04/14/jenrees-4-14-19/. Take homes: In none of the studies did the addition of 30-50 lbs N/ac above the recommended rate increase the yield statistically. A few of these studies also compared side-dress applications vs. pre-plant alone. One situation resulted in a statistically lower yield with pre-plant alone while the other two resulted in no yield differences. Many of you have most likely heard of Project Sense in which a grower’s nitrogen application was compared to 75 lbs pre-plant + variable rate in-season application using sensing technology. This project was an on-farm research partnership with Nebraska Extension, Nebraska Corn Board and Corn Growers, and numerous NRDs including UBBNRD. From 2015-2017, 48 site-comparisons were conducted. The results showed 28.7 lbs less nitrogen was applied using the Project Sense method with a loss of 1.4 bu/ac in yield, and greater profitability of $7.24/ac. All of these results were statistically significant at the 95% level.
To reduce the risk of leaching or denitrification, consider applying the majority of nitrogen close to when crop demand is high with more nitrogen applied during the growing season vs. pre-plant. Also for consideration is the fact that farm operations differ in equipment and labor and growing seasons like 2019 present additional challenges, including for nutrient management.
Crop Updates: An increase in disease pressure has been the theme the past few weeks. Sudden death syndrome is increasing in soybeans, but there’s also brown stem rot (BSR) and frogeye leaf spot in some fields. The foliar discoloration is the same for SDS and BSR with the yellow/brown discoloration between leaf veins. You can tell the difference by pulling a plant out of the ground. SDS is usually easy to pull as the taproot is rotted. Splitting the stem open, the root will show rot at the soil line but the stem pith will be white and healthy. With brown stem rot, the pith will have brown discoloration. The addition of stem borer can make it more difficult to tell the difference sometimes. Unfortunately there’s nothing one can do for SDS or brown stem rot now as both are caused by soil borne fungi. I would recommend taking soil samples for soybean cyst nematode (SCN) in areas currently impacted by SDS as the combination of diseases is synergistic in impacting yield loss. You only need 0-8” samples and they can be taken during soil fertility samples if you don’t want to take them now. The samples are free via your checkoff dollars and they can be sent to the Plant and Pest Diagnostic Lab at UNL in Lincoln.
In corn, foliar disease is increasing in mid-canopies. Most concerning are the number of stalk rot samples/situations I was called to the past week. They all appear to be bacterial stalk rot thus far. Symptoms include watersoaked nodes and below the nodes with plants breaking off/falling over. Damaged nodes are from the soil line to upper canopy. The bacteria disintegrates these stalks creating a stringy appearance within them where the nodes break and when slitting open stalks. It also has a distinct foul smell. This is more of a problem in wet years such as this and hybrid susceptibility varies. The bacteria doesn’t typically transfer from plant to plant. I have photos of what I’m seeing on my blog at https://jenreesources.com.
There have been multiple late-season hail events in the area. For those fields hit by the August 6th storm, the rainy, cool conditions have allowed for increase in mold on the hail damaged side since many of those damaged ears were at milk stage. However, I’m also seeing mold damage on some back-side of ears in hybrids with tighter husks. The white/pink fluffy growth on the hail damaged side is caused by Fusarium/Gibberella fungi. The presence of these fungi does not automatically mean mycotoxins are present; they do have the potential to produce mycotoxins. The green fungal growth in ears are caused by secondary and minor fungal pathogens that don’t produce mycotoxins. The white fungus overtaking ears on some tight-husked hybrids is diplodia which can cause for light test weight but does not produce a mycotoxin. It will be important to continue to watch grain quality over time prior to harvest.
Wild and Burcucumber on Trees has also been a huge question. Do Not apply 2,4-D to trees for
control as that has been the most common question! The simplest way to kill wild and burcucumber is pull or hoe the plant at its base below the tree. There’s not much to the plant root and the vines will then die on the tree!
It’s been a hard year for our growers and livestock producers with continued challenges. Seeking to end this column on a positive note, this year is the 10th year of the Nebraska State Fair in Grand Island and the 150th Fairabration. I’m grateful for the focus on agriculture, families and youth! And, it’s encouraging to me to see youth learning life skills whether competing in public speaking, working with and showing livestock, or studying and competing in contests such as weed and grass ID at the State Fair. 4-H is where I got my start and it’s exciting for me to wonder at the futures these 4-H and FFA youth have ahead of them as they continue to work hard and put into practice the life skills they are learning! Hope you can make it out to the State Fair at some point!
*End of News Column. Bacterial stalk rot photos below.
Reducing Nitrogen Losses: Most growers I’ve interacted with desire to be good stewards of the land and leave it better for future generations. Economically, they also need to be increasingly efficient in how they farm. One of these stewardships and efficiencies comes in preventing nitrogen losses and individual farm situations may differ in how the risk of those losses is reduced.
Nitrogen losses occur three primary ways: Leaching, Denitrification, and Ammonia Loss.
1-Leaching: All nitrogen fertilizer eventually converts to the nitrate-Nitrogen (nitrate-N) form. This form has a negative charge and is not held by negatively charged soil particles. Thus excessive rains can allow for leaching of nitrogen below the plant root zone, particularly in sandier soils. Fertilizers that are already in the nitrate form such as urea ammonium nitrate (UAN) and ammonium nitrate are susceptible to leaching upon application. Soil microbes can convert urea to nitrate-N within two weeks in late spring, making it susceptible to leaching loss. Anhydrous ammonia takes longer to convert to nitrate-N because it initially kills soil microbes that would convert it. Less conversion occurs once soil temperatures consistently reach 50°F and lower without excess soil moisture.
2-Denitrification occurs in saturated soil conditions where certain soil bacteria can survive and thrive. The bacteria convert nitrate-N to oxygen and nitrogen gases resulting in nitrogen lost to the atmosphere. Heavy, poorly drained, compacted soils are most susceptible to loss via denitrification.
3-Volatilization occurs primarily in urea based products such as dry urea or liquid urea-ammonium nitrate (UAN) when applied on the surface and not incorporated via rain or tillage. The urea in these situations is converted to ammonia gas via urease enzymes in the soil and plant residues. Up to 15-20% of urea can volatilize within a week after application if the conversion occurs at the soil surface during warm, sunny days, particularly in high residue situation, pH levels greater than 7.0 and on light textured soils. If the urea is injected or incorporated after application, or if half-inch of rain/irrigation is received within 24 hours after application, volatilization risk is essentially eliminated.
In general, to reduce the risk of leaching or denitrification, our Extension Soil Fertility Specialists recommend considering applying the majority of nitrogen close to when crop demand is high with more nitrogen applied during the growing season vs. pre-plant. Research has included in-season and split applications including side-dress with and without use of crop sensors, and/or fertigation. The use of inhibitors is not advised in season as research showed they can release N too slowly for the crop demand resulting in yield loss and/or resulting in increased leaching of nitrogen when it was released too late in the growing season for crop uptake. Inhibitors may help reduce risk of leaching or denitrification pre-plant, but they are not a silver bullet and need to be well targeted in order to aid in reduced nitrogen losses. In general, the research is more supportive for inhibitor use in sandy soils vs. heavier textured soils; yield benefit to a nitrification inhibitor may be none to a few bushels/acre for silt loam or silty clay loam soils. The duration of inhibitor effects depends on soil temperature and may be as little as 1-2 weeks or as much as 6 weeks with spring pre-plant applications. Split application was likely more effective than use of most inhibitors to reduce leaching loss.
Places where inhibitors could be well-targeted to high risk nitrogen loss situations include: urease inhibitor reducing ammonia volatilization with delayed rainfall after urea or UAN broadcast to no-till fields, wheat and pastures, and/or soil pH >7.2; nitrate leaching in a wet spring, especially with sandy soil; denitrification and nitrous oxide emission for poorly drained soil subject to flooding. Other research-based recommendations include considering the addition of alfalfa in rotation 5 of 10 years and including a cover crop in situations where excess nitrate-N may occur, such as seed corn. Two tools developed by UNL for helping quantify the risk of nitrogen loss include the Nitrogen-Loss Assessment Tool (N-LAT) and Maize N which can be accessed at: https://cropwatch.unl.edu/soils.
Crop Update and Hail Damage: While I don’t remember numbers as well, calendar dates are something I tend to remember. And, in agriculture, there’s numerous dates that accumulate over one’s life from hail, tornado, blizzard, flood, and wind events. I was reflecting on the Aug. 6th hail storm that occurred in Merrick, York, and Seward counties in 2018. This past week on August 7th, some woke up to hail/wind damage in Adams, Clay, and Nuckolls counties. The tree damage was incredible. Michael Sindelar, Clay Co. Educator, and I surveyed damage a day later. My estimation of the worst hit crops: corn around 80% defoliation with varying percentages of greensnap above/below ear and soybeans around 50% defoliated/broken off/with at least 50% pods on the ground. Where hail stones hit the ears, the kernels are mushy and mold is already setting in on corn at milk stage. There’s also mold setting in on soybean pods hit with hail stones. It’s hard to receive crop damage any time. The good news is that nothing appears to be a total loss; the majority of what we looked at was less than 40% defoliated and in general, the hail did not seem to penetrate the stalks, thus early stalk rot doesn’t appear to be setting in. Pictures at https://jenreesources.com.
Tree Problems: The majority of my questions the past 10 days were regarding tree leaves turning yellow and dropping from trees. They look stark against green grass. In general, what’s happening is the fact that we’ve had high humidity for a period of time now and we’ve had rain throughout spring and summer. Fungal pathogens thrive in these conditions. So, ornamental/flowering pears have pear rust; crabapples and apples have scab and also cedar-apple rust (depending on varieties); maples, ash, sycamores are showing anthracnose; and a number of other fungal leaf spots are observable on shade trees in general. Evergreen trees show various fungal needle spots. Ultimately, we don’t recommend doing anything for these diseases this time of year. We typically don’t recommend to spray shade trees in general, but fruit and evergreen trees should be sprayed in the spring if fungal diseases have occurred in the past. So, fungal diseased leaves may drop early and you may or may not observe a new flush of leaves yet this year. These fungal diseases won’t kill deciduous trees. They can kill evergreen trees over a period of years.
Oak leaves turning brown in clusters was also observed this past week. Sometimes
browning of leaves can be due to a fungal disease called anthracnose. Most of what I’m seeing, I believe, is environmental. It could be due to changes in hot/cool and periods of heavy moisture followed by lack of moisture on trees that had a huge flush of leaves due to moisture this spring. I really don’t know the cause for sure, but it doesn’t appear to be disease related from what I can tell. We wouldn’t recommend doing anything for the trees at this time.
UBBNRD Public Hearing: The Upper Big Blue NRD will hold a public hearing and informational open house on Aug. 19 at 7:00 p.m. at the Holthus Convention Center. The purpose is to receive comments on proposed changes to District Rule 5 – Ground Water Management Area Rules and Regulations. A complete copy of Rule 5 and the proposed changes are available at the district office and at www.upperbigblue.org/publichearing. The public will have the opportunity to learn more about these proposed changes and their effects, and address NRD board members about their concerns or support.
The proposed changes would stipulate that an approved nitrification inhibitor must be applied at the manufacturer’s recommended rate with pre-plant nitrogen fertilizer in the following situations: The application of anhydrous ammonia prior to March 1; The application of all nitrogen fertilizers other than anhydrous ammonia after February 29. In addition to these requirements, in Phase II and Phase III areas pre-plant application of nitrogen fertilizer shall not exceed 120 lbs. per acre. The remaining nitrogen fertilizer may be applied post plant. Prior to applying nitrogen fertilizer, but no later than April 1 of each year, each operator in the management area will be required to report information regarding the use of best management practices. For more information, visit www.upperbigblue.org or call (402)362-6601.
York County Corn Grower Plot Tour will be held Aug. 20th from 5-7 p.m. at 1611 Rd. 14 east of York. Pizza and refreshments will be provided and check out the latest hybrids. Guess the winning yield without going over and win a $50 gas card. All are welcome!
*End of News Column. Hail damage photos below.
Thank you to everyone who “pulled together” to make the 2019 York County Fair a success! Reminder of the Seward County Fair in Seward August 8-11 and you can find details at: http://sewardcountyfair.com/.
Cash-Rent Workshops: Nebraska Extension land specialists will address common agricultural landlord and tenant questions such as: What does an equitable rental rate look like for my land? How do I manage a farmland lease? How could the lease be adjusted for recent flood damage? What should I expect for communications between the landlord and tenant? What are key pasture leasing considerations including stocking rates? Who is responsible for cedar tree removal from grazing land? What does it cost to raise crops on my ground? The closest locations to our area are listed below. Registration is 15 minutes prior to start time. The cost is $15 per person or $25 per couple. Registration will include refreshments and handouts.
- Aug. 8, 10 a.m. – 2 p.m.: Eastern Nebraska Research and Extension Center near Mead (includes lunch). RSVP: 402-624-8030 or firstname.lastname@example.org
- Aug. 19, 10 a.m. – 2 p.m.: St. Paul Community Library, 1301 Howard Ave., St. Paul (includes lunch). RSVP: 308-754-5422 or email@example.com
- Aug. 20, 9 a.m. to noon: Saline County Extension Office, 306 W 3rdSt. Wilber. RSVP: 402-821-2101 or firstname.lastname@example.org
- Aug. 21, 1 – 4 p.m.: Lancaster County Extension Office, 444 Cherrycreek Rd., Lincoln. RSVP: 402-441-7180 or email@example.com
Nebraska Soybean Management Field Days will be held August 13-16 and will offer farmers research-based information to improve their soybean profitability. Locations are Sargent on Aug. 13; Pilger on Aug. 14th; Plymouth on Aug. 15; or Waverly on Aug. 16. The field days begin with registration at 9:00 a.m. and conclude at 2:30 p.m. More details at: https://go.unl.edu/2019smfd. Topics include: Making Sense of Production Costs and Policy Changes; Soybean Insects & Cover Crops; Hail Damage Impact on Growth & Development of Soybeans; Management of Cover Crops & Soybean Insects and Pathogens; Soybean Weed Control & Cover Crops; Cover Crop – Pros & Cons Associated with Soybean Production; Soybean Production & Agronomic Topics Associated with Cover Crops – Planting Rates, Row Spacing, Planting Dates, Maturity Groups, Irrigation Management. CEUs available for Certified Crop Advisors.
Soil Health Workshop will be held on August 22 at the Eastern Nebraska Research & Extension Center near Mead. This hands-on workshop is geared for anyone interested in learning more about soil health including home and acreage owners, farm operators, and industry consultants. Topics include: management considerations to improve soil health; measuring bulk density, porosity and infiltration and the impact on soil health; physical soil properties – the foundation for soil health; cover crops for improving soil health; what is soil biology – active carbon test; soil characteristics, productivity and landscape position; and chemical soil properties. CCA credits have been applied for (6.5 Soil & Water Mgt.). Details at: https://enrec.unl.edu/2019MidwestSoilsClinic.pdf or call (800) 529-8030.
West Central Crops and Water Field Day will be held on Aug. 22 at the West Central Research & Extension Center in North Platte. Registration begins at 8 a.m. with program from 8:45 a.m.-5 p.m. This Field Day offers a unique opportunity for anyone interested in water to learn and see irrigation practices and cropping systems on a farm scale that maintain or increase crop production while conserving water. Approximately 25 commercial vendors will be on hand to provide live demonstrations of how their products can help farmers manage their fields. UNL-TAPS updates and field tours will be included. Details at: https://extension.unl.edu/statewide/westcentral/water-crops-field-day/.