Soil Moisture 5-10-18
The area of ‘abnormally dry’ or ‘moderate drought’ was reduced by 5% in Nebraska as of 5/8/18 compared to the previous week.
This site has continually missed the rain. The first foot can be observed as slowly drying out as well this week with total soil moisture (1-4′) remaining above 50% depletion. This site was removed due to corn being planted in this field.
Last week’s rains did help the first and second feet remain below field capacity. However, the third foot did not remain wet after the rainfall event and can be seen climbing in depletion in the graph this week. I did probe this site this week and there appears to be good moisture now just past 2 feet, but it gets dryer after that.
This site continues to remain steady with total soil moisture depletion around 35%.
The first foot sensor has leveled off after being reprimed on 4/26. Total soil moisture depletion (1-3′) remains around 45%.
Last week’s rains helped with the first foot and somewhat with the second foot at this site. Total soil moisture depletion is around 40%.
JenREES 5-13-18
It was great to see so many fields of corn and even soybean emerging throughout the
area this past week! Also grateful for the rain we received in York and for those who received some in other areas. There are still areas who continue to miss rains and I remain concerned about the soil moisture situation. I have another soil moisture update this week at http://jenreesources.com if you’re interested in checking that out.
Thursday night/Friday morning’s high winds caused some damage with overturned pivots/corner systems and tree damage. We also saw newly emerged corn and even soybean cut off or
Corn plants were buried or cut off by blowing residue/soil. A few remaining plants in this area of the field can be seen.
buried due to blowing debris/soil, particularly in soybean stubble. It will be important to watch the plants in these fields the next several days. By late Friday afternoon, I was already seeing new growth occur, which is good. Typically, that has been the response in the past-new regrowth in corn as the growing point is still below ground. However, it will be important to watch the corn plants for any bacterial issues that may kill seedlings. One can also split open a few plants and look for a healthy growing point. Regarding the soybean, I have seen soybean lose cotyledons due to hail, crusting, freeze, and wind damage, and still produce a plumule at the top of the soybean stem. It’s just hard to know for sure what will happen so it’s best to watch the plants in the fields.
Wheat in Nuckolls, Thayer, and Webster counties ranges from elongation to near boot and is turning blue-gray from moisture stress. Wheat is a crop that I’m always learning about-it can look really bad (or really good) and then end up surprising a person regarding yield either way. Lower leaves
in fields are turning yellow-brown. Some of this is due to moisture stress while there’s also powdery mildew pretty thick in lower canopies of wheat that had more tillers. A few have talked with me about using the wheat for hay or silage and then potentially going in with short season corn, sorghum, or a forage crop. Our forage specialists would recommend that if the wheat variety has awns, it’s best to either take for hay or silage at the boot stage so the awns don’t cause issues with livestock feeding. Todd Whitney, Extension Educator in Phelps/Gosper counties, had worked with a feedlot using an awnless wheat variety. Because of the additional growth that occurs in wheat (and other small grains) from boot to full head elongation, they found biomass production may be increased 25% if the forage was harvested during the later pollination period.
Evergreen Trees: There’s also been a lot of evergreen tree questions. For those noticing spruce trees looking kind of yellow with early morning sunlight, spruce spidermites have been working hard with the cooler, dry weather. They tend to build populations in spring and fall. You can check for spidermites by taking a white piece of paper and banging the needles on it. Then look for the presence of tiny dark green to nearly black spidermites crawling on it. Rainfall is a great way to wash them off of trees as are strong streams of water (easier done with smaller trees). There are also a number of miticides available that homeowners can purchase from lawn and garden stores (look for products that say they can be applied to trees for control of spidermites). A great brochure on insect pests of evergreen trees can be found at: https://nfs.unl.edu/documents/foresthealth/insectevergreen.pdf.
Many of us also noticed our spruce trees turning red/brown/purple/yellow in color last fall. This is most likely a disease called needle cast of spruce and can be prevented by spraying trees now (mid-May) with a product containing copper sulfate. Regarding Ponderosa or Austrian pines, if you look closely at the needles and observe dark bands or rings on them followed by death of the needle either direction from the band, the tree problem is most likely due to a fungal needle blight like dothistroma or brown spot in Scotch pines. They can all be prevented by spraying a fungicide containing copper sulfate now. The following brochure on diseases of evergreen trees is really helpful: https://nfs.unl.edu/documents/foresthealth/diseasesevergreen.pdf. Sometimes the problem is finding the products listed on these brochures in our smaller towns as these brochures were developed in Lincoln. If these specific products aren’t available from your local lawn/garden store, box store, or coop, I would recommend looking at the products available and look for a product that says it is effective against needle blights on trees. Not all the products I’m seeing have copper as an active ingredient, but other fungicides are listed and the key would be the fact that the site (trees) and even better, the site with problem (trees with needle blights), is listed on the label.
We also continue to see pine wilt affecting our Scotch (short needles in groups of 2) and Austrian pines (long needles in groups of 2). Pine wilt disease is caused by the pinewood nematode that is carried within the gut of a long-horned beetle. The beetle is what creates the ‘shotholes’ often seen in bark of infected trees. The nematode is native to Nebraska, as are Ponderosa pines (long needles in groups of 2 and 3). This is why we don’t see the problem in Ponderosa pines but do in Scotch and Austrian, which are non-native to Nebraska. A tip, if you’re trying to distinguish Ponderosa vs. Austrian pines, anytime you see needles with a group of 3 it’s a Ponderosa. Pine wilt is caused by beetles carrying pinewood nematodes vomiting them into the water-carrying vessels of the tree (xylem). The tree senses the nematodes and essentially blocks water to those branches. Often you will observe a branch then perhaps a side of the tree and eventually complete death of the tree within 6-9 months. While I have diagnosed many samples of pine wilt, more often when I visit homeowners the tree problems are due to fungal diseases which occur on the needles.
Lawns: Please remember the importance of sweeping or blowing fertilizer and pesticide products back into the lawn instead of leaving them on sidewalks. Leaving them on the sidewalks puts them in contact with people and pets walking on sidewalks and moves them into storm water systems via rain that can eventually end up in streams. I’m also seeing a number of 2,4-D/dicamba products being sprayed around tree bases to kill weeds which is affecting the new growth emerging on trees. Consider applying a wood mulch layer around the base of trees to help avoid this situation in the future and be sure to read and follow all pesticide labels.
JenREES 5-6-18
What a beautiful weekend! It was a welcome change from the winds we received last weekend and early week. The high winds early in the week created difficult situations from many perspectives-soil loss, visibility, accidents, and drying out the seed bed.
Great to see several on-farm research plots going in and to have some new cooperators this year! I also started a very small soybean planting date demo at the York County Fairgrounds on April 24. A farmer on Twitter was encouraging other farmers to try planting a few seeds every week for yourselves in a garden plot and count the nodes and pods. Thought it was a great idea and will have it signed at County Fair regarding soil temps for first 48 hours and nodes. Thanks to Jed Erickson from Pioneer for the seed!
Rain events on May 1-2 allowed for some soil moisture recharge in the first and second feet in some locations. Unfortunately, the rainfall was still fairly spotty. We could really use rain overall for getting moisture back into drying seedbeds, activating herbicides, and settling dust. Pivots are running in some fields because of these factors. I provided an update on the locations I’m monitoring regarding soil moisture as of 5/3/18 on my blog at http://jenreesources.com. The farmers were interested in continuing this monitoring throughout the growing season this year, so will continue sharing as often as I can.
Wheat: Wheat’s joined in the area and ranges in height depending on soil moisture. For the past few weeks we’ve been noticing yellowing leaves. Some of that may have been due to cold temperatures. I was also seeing powdery mildew within the canopy of several fields I looked at. No rust has been observed yet in Nebraska fields. I also noticed tan spot in wheat on wheat fields. One concern was the cool weather has allowed for bird cherry oat aphids in area wheat. My concern is that they can vector barley yellow dwarf virus which is one we see when the flag leaf emerges. According to K-State, there’s not strong developed thresholds. They’re recommending if 20 or more aphids are observed per tiller with lady beetles observed on fewer than 10% of tillers, spraying may be justified.
Lawn and Garden Information: With this year’s cool spring, crabgrass preventers can still be applied the first few weeks of May. Germination begins with soil temperatures around 55F but prefers warmer soil temps. UNL Lawn calendars for Kentucky Bluegrass, Tall Fescue, and Buffalograss and all UNL lawn resources can be found at https://turf.unl.edu/turf-fact-sheets-nebguides. Mowing heights should be maintained at 3-3.5″ for the entire year. We also recommend just mulching clippings back into the lawn to allow for nutrient recycling. If you like to use mulch for your gardens, it’s important to read pesticide labels on products applied to your lawn. Some labels say it is not safe to use the clippings as mulch. Others say to wait at least three mowings before using the clippings as mulch.
Garden centers have been busy with the warmer weather and some have asked about temperatures for hardening off transplants. Kelly Feehan, Extension Educator in Platte County shares, “May is planting time for most annual flower and vegetable transplants. To avoid transplant shock and stressing young plants, wait for soils to warm up and take time to harden off transplants. Soils are colder than average this year so waiting to plant will be beneficial. And then, plants moved directly from a warm, moist greenhouse to windy and cooler outdoor conditions will be stressed by transplant shock. This can negatively affect plant growth, flowering, and vegetable production. Harden off transplants by placing them outdoors, in a protected location, for at least a few days before transplanting outdoors. Another way to harden transplants is to plant them in the garden, then place a cardboard tent or wooden shingle around them for a few days to protect them from full exposure to wind and sun. Planting young transplants on an overcast, calm day or during the evening also reduces transplant shock.” Specifically when it comes to tomatoes, it’s best to wait till mid-May otherwise “gardeners who plant earlier need to be prepared to protect tomato plants with a floating row cover or light sheet if cold threatens. To help tomato transplants establish quickly, begin with small, stocky, dark green plants rather than tall, spindly ones. Smaller plants form new roots quickly and establish faster than overgrown transplants. Do not plant too deep or lay tomato stems sideways. Although roots will form on stems below ground, this uses energy better used for establishment. Use a transplant starter solution after transplanting tomatoes to be sure roots are moist and nutrients are readily available in cool soils. Wait until plants are growing well before mulching or mulch will keep soils from warming and may slow tomato growth.”
Soil Moisture 5-3-18
Today was interesting driving my route through the southern tier of counties I serve. Wearing overboots and walking instead of driving to the sensors was welcome at Byron and Superior where heavier rain events occurred this week. However, Lawrence and Bladen had largely missed the rains. The Clay Center location received 1″ the past two days, but other areas of Clay County received very little. The farmers who have allowed me to monitor pre-plant soil moisture thus far were interested in watching this throughout the growing season. Thus, sensors will remain in most of these fields. Where fields have been planted thus far (other than Clay Center), planters have planted around the sensors and seeds have been hand-planted between sensors.
The Nebraska Drought Monitor Map updated 5/1/18 (before the rain events the past few days) showed expanded areas of ‘abnormally dry’ (yellow) and ‘moderate drought’ (tan). Stars show the locations of soil moisture monitoring equipment.
This location essentially missed the rains this week with the top foot remaining around field capacity and 2-4′ near 40% depletion or above. Wheat near this location had jointed but was shorter than at Lawrence and Superior.
This location has been interesting to monitor. Last week I mentioned that moisture received wouldn’t be enough to maintain the second foot near field capacity after 4/26 (which is true from the climb observed in the second foot). This location received 1.5″ the past two days. With the top foot at field capacity, it makes sense that today it is showing near saturation with the second foot dropping below field capacity as well. I should have probed the soil to see if moisture truly reached the third foot or not. The chart shows the third foot also filling below field capacity. We will know more from next week’s graphs. Being a no-till field, the rain soaked in well even though it appeared to come hard from the way the road had washed in spots and was super soft.
This location received some misting as I was collecting this data, but the sun soon came out and steam began rising from this field and the soybean field across the road (next graph). Essentially 0.05″ of rain was received at this location and the graph remained unchanged this week for the most part other than increasing soil temperature.
At this soybean location, something had caused for a disconnection in the 1st foot sensor last week, so I reprimed the sensor on 4/26. I didn’t take out the first 48 hours in this graph (which we say is normal time to acclimate to the soil). The first foot is currently showing over 15% depletion this week with total soil moisture depletion near 50%.
This location received 1.25″ of rainfall the past few days which helped the second foot recharge to near field capacity and the total soil moisture (1-4′) be near 35% depletion. Wheat near this location had jointed and elongated a great deal compared to last week.
Beginning Soil Moisture 4-26-18
Some rains helped with the top foot profile at some of these locations last week. One thing to keep in mind when viewing these graphs is we don’t always know what’s going on below the soil surface. One farmer had a good point regarding my “blips in the graphs” in my last blog post. I mentioned they could be due to a soil crack along the PVC pipe-which we do see occur and can be true. However, he also had a good point that it could be a worm hole, root channel, etc. that water may have followed for a brief time period, which could also be true, especially in these long-term no-till fields. As you look at the charts this week, it’s important to keep in mind that soil water also moves via gravity (termed ‘gravitational water’). Thus, sometimes why we can see changes in soil moisture in the successive drier layer with small amounts of precipitation.
Nebraska Drought Monitor as of 4/26/18 showing increasing ‘abnormally dry’ areas of the State. The ‘moderate drought’ area has expanded further into Webster and Thayer counties. Stars show locations where I’m taking pre-plant soil moisture status.
Beginning soil moisture at Bladen remained relatively unchanged last week. The top foot went back to around field capacity with some rain events. Total soil moisture depletion is above 50% at this site as are all soil layers from 2′-4′).
Moisture last week did appear to re-wet the top 2 feet. I even probed the soil in the same area to ensure there was truly moisture in the second foot, which there was. Yet as you can see from the graph, the second foot was starting to climb when I took these readings. My guess is without additional precip, the second foot will be above field capacity again next week.
Because the top two feet were already around field capacity, gravitational water along with moisture received last week may have created the dip in the third foot readings seen over a few days. It was rising back up to above 50% completion on 4/26. The sensors were removed on 4/26 as the field was planted to soybean that day.
This location received 0.20″ of rain last week with essentially no change in soil moisture status from the previous week. Total soil moisture (1-4′) is steady around 35% depletion.
This location also received around 0.20″ of rain last week. Something happened to create a short in the top foot sensor, thus, the lack of data for 1′ and total (1-3′) after 4/22. It was fixed on 4/26.
This location received around 0.60″ of rain last week. The top foot remained steady and there was a gradual decrease followed by increase in soil moisture in the second foot. This would make sense from the combination of gravitational water and the precipitation moving through the first foot into the second, but the moisture wasn’t enough to maintain the second foot at a wetter moisture level.
JenREES 4-29-18
Crop Update: It’s nice to see some signs of spring with planters going this 
week/weekend, crabapples and flowering pear trees in bloom, and tulips budded! The York County Corn Grower plot got planted on Saturday and grateful for Ron and Brad Makovicka’s efforts with that and for all our participating companies!
Rain did help the top foot of sensors in some locations I’ve been monitoring for pre-plant soil moisture. The graphs will be up at http://jenreesources.com by noon on Monday. The cooperators have all been interested in continuing to monitor moisture in these fields post-planting, so will plan to do that and add a York and Seward location too. I’m noticing in York as lawns are greening up, that portions are looking gray-green in color where trees are located in them.
As of April 26th, I hadn’t found any wheat jointing yet. The growing point was just approaching ground level in several fields I checked. We also need to keep an eye out for stripe rust as incidence is increasing in Kansas fields. There’s articles focusing on winter wheat in this week’s UNL CropWatch at http://cropwatch.unl.edu including nitrogen management and Nebraska wheat progress.
Wheat Stem Maggots (WSM) in Rye/Wheat Cover Crops: I meant to provide an update in last week’s column. Dr. Justin McMechan has been scouting wheat and rye cover crop fields for wheat stem maggots. So far, he captured one adult wheat stem maggot on April 16 in 100 sweeps from a wheat cover crop planted in late September at the Eastern Nebraska Research and Extension Center near Ithaca. He shared that “adults have been consistently collected at this location since first emergence with one to two found per 100 sweeps. This first occurrence of adults matches closely with data collected in 1933 by Merle Allen from Kansas State University. Our latitude north of Kansas and cold spring suggests this emergence might be earlier than Allen’s data. On April 23 two adults were collected at Clay Center and a single adult was collected near Marquette. Cover crops in these fields were less than 6 inches in height, with the field near Marquette grazed to approximately 3 inches in height. Sweeping these fields is challenging due to the height of the vegetation so adult captures are not likely to represent true numbers in the field. If you are skilled with a sweep net, we encourage you to sweep your wheat, rye, or triticale cover crops for wheat stem maggot adults.” At this point we’re not recommending any insecticide treatments. An interesting observation that a couple of Clay and Adams county farmers mentioned to me last year was they noticed the presence of a lot of flies as they planted corn into green rye and terminated at or after planting corn. The adult WSM is a small fly and you can see photos in Justin’s report in this week’s UNL CropWatch at http://cropwatch.unl.edu.
Which dicamba product before Xtend soybean: This has been a fairly common question this spring which Dr. Amit Jhala addressed in this week’s UNL CropWatch. I’ve also provided his answer here. “I recently received several phone calls from growers with questions on terminating broadleaf cover crop species and broadleaf weeds using dicamba products. They were particularly interested in whether dicamba products such as Banvel, Clarity, DiFlexx, etc. can be applied to terminate broadleaf cover crop species such as hairy vetch, field peas, or mixtures and broadleaf weeds such as henbit, field pennycress, or marestail immediately before planting Xtend soybean. The answer for the dicamba-based herbicides listed above is NO. Their labels have soybean planting intervals of 14 to 60 days, depending on the product and its use rates.
For example, for Clarity to be applied at 16.0 fl oz/acre, there would be a 28-day soybean planting interval after an inch of rain. If Clarity were to be applied at 8.0 fl oz/acre, the soybean planting interval would be 14 days after an inch of rain. The Clarity label also specifies: “Do NOT make Clarity burndown applications to soybeans in geographic areas with average annual rainfall less than 25 inches.”
If DiFlexx is applied burndown at 24 fl oz/acre or less, the planting interval for soybean is 60 days. This longer planting interval must be applied because Xtend soybean is not listed on Banvel, Clarity, DiFlexx, or other dicamba products.
Dicamba-resistant soybean, also known as Xtend soybean, became available commercially for the 2017 growing season. Three dicamba products (FeXapan, Engenia, XtendiMax) are labeled to be applied pre-plant, pre-emergence, or post-emergence (up to R1 soybean growth stage) for broadleaf weed control in Xtend soybean. You can use FeXapan, Engenia, or XtendiMax as per label requirements in burndown application and plant Xtend soybean without a planting interval.
If you apply 2,4-D prior to planting soybean, be sure to adhere to the planting interval specified on the label. Several 2,4-D products have different planting intervals for soybean, ranging from 7 to 30 days depending on product and application rate. (See this Crop Watch article.)”
JenREES 4-22-18
Planting Considerations: This email newsletter reaches a wide area of the State, so soil temps vary quite a bit and some of you may be in better planting conditions than others. We still recommend planting into soil temps as close to 50°F as possible, check weather conditions for next 48 hours to hopefully maintain temps 50°F or higher, and avoid saturated soil conditions. If planting a few degrees less than 50°F, make sure to check with seed dealers on more cold-tolerant seed. This is most likely common sense, but I still feel worth mentioning. Everything we do at planting sets the stage for the rest of the year. We’re blessed to have equipment that can allow for many acres to be planted in a short amount of time. And…we also have the ability to mess up a lot of acres in a short amount of time.
Planting depth is also key. Aim to get corn and soybean in the ground 1.5-2” deep. This is critical for correct root establishment in corn to avoid rootless corn syndrome. Rootless corn syndrome is when the nodal (crown) roots don’t get well established and successive brace roots can’t establish either. This allows the seedling to whip around in the wind, potentially being dislodged, become weak or die. With center-fill planters, when adjusting down-pressure on the go, sometimes the planter ends may not always be seeding as deep as the center. Too often I’ve seen that resulting in seed 1” or less and the field pattern can be observed the entire growing season with potential yield impacts. So don’t just rely on the monitor. Take the time to dig up seed behind the planter and at spots along the whole planter length to ensure the proper seeding depth. And do this with every field, particularly with different tillage/residue situations. I realize this takes time, but you’ll be glad you did to catch any issues before too many acres are planted incorrectly.
With cold temps or higher soil moisture conditions, it’s still important to get that seed at least 1.5-2” in the ground. Planting 1.5-2” deep helps both corn and soybean to have that seed in even soil temperature and moisture conditions. You may be surprised on that recommendation for soybean, but I think it’s even more critical with planting early. In fact, UNL research near Mead compared planting depths of 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, and 2.5 inches in 2011 and an additional planting depth of 2.75 inches was added in 2012 and 2013. The study found lowest yields when soybean was planted 1.25” or less or 2.25” or greater with the highest yield at 1.75” deep. One of that study’s hypotheses was that planting deeper would buffer soil temperature and moisture and protect newly emerged seedlings from frost and freeze damage, particularly when planting early in the season.
Hopefully planting soybean early is still something you’re considering for this year! We wrote a CropWatch article this week at http://cropwatch.unl.edu to provide some updated research on amplifying the effects of planting early. There’s so much research regarding how early soybean planting increases yield that we wanted to share new research regarding maturity groups, etc. Essentially, what it appears from the research thus far, is that it’s more important to choose a consistent, high-yielding soybean for your area, regardless of specific maturity group. We’d like to get more specific data and have on-farm research protocols available to compare MG2.4-2.5 vs. MG3.0-3.5 and Dr. Jim Specht would also like to collaborate with us on documenting various factors. Please let me know if you’re interested in this! There’s also a protocol for comparing early vs. late planting of soybean.
Soil moisture conditions didn’t improve this week at the six sites I’m monitoring in Webster, Nuckolls, Thayer, and Clay counties. You can find the chart comparisons on my blog at http://jenreesources.com. Last weekend’s bizzard didn’t provide significant moisture in this area. With pastures slow with growth and drought increasing in Kansas, discussions with farmers have included cover crop termination, grazing rye that’s had anhydrous ammonia applied to it (with the original intention of termination and planting to corn), and grazing wheat. Most of these topics are included in this week’s UNL CropWatch at http://cropwatch.unl.edu. The articles are too long with too many considerations for me to add them in this news column, so please do check them out if you’re interested in these topics. Another topic I’ve had several questions about is regarding how temperature and rain affect burndown herbicide applications. Dr. Amit Jhala, Extension Weed Specialist, addresses that in this week’s CropWatch as well, so please check that out. Here’s wishing everyone a safe planting season with conditions to get #plant18 and #grow18 started off well!
Beginning Soil Moisture 4-19-18
Here is an update on beginning soil moisture status. The left charts are as of 4/19/18 with the right charts being the previous week. You can click on the images to enlarge them. The ‘weekend moisture’ event I refer to was the blizzard 4/14/18.
Bladen: The top foot is now slowly losing moisture one week later in spite of some weekend moisture. The second-fourth feet are all above 50% depletion.
Byron: Some weekend moisture may have allowed the top foot to remain steady. The second and third feet are both over 50% depletion bringing the total soil moisture in the 1-4′ depths closer to 50% depletion. There must have been a soil crack along my PVC pipe to allow for the moisture spike you see in 3 and 4 feet and not 1 and 2 foot depths.
Clay Center: This is still the wettest location in spite of the top foot slowly drying out this week. The second foot is still below field capacity with third and fourth feet and total soil moisture relatively unchanged. Must have had a soil crack along PVC pipe for third foot for the quick dip observed.
Lawrence Corn Stubble: Minimal change was observed at this location this past week. Essentially all feet remained the same in regards to soil moisture. A small crack along PVC pipe must have been present at 3 foot for short dip observed there.
Lawrence Soybean Stubble: This location (across road from corn stubble) showing dryer than last week. Top two feet now dryer than field capacity which increased the total (1-3′) soil moisture depletion.
Superior: Weekend moisture may have allowed the top foot to stay steady (as was also seen in Byron). However, the second, third, and fourth feet all lost moisture leaving the total soil moisture (1-4′) above 35% depleted at this location.
JenREES 4-15-18
Well, winter seems to be sticking around. My thoughts and prayers have been with those of you calving with the difficult conditions this year.
I provided an update regarding soil moisture status in non-irrigated fields both in this week’s UNL CropWatch at cropwatch.unl.edu and my blog at jenreesources.com. We’ll see what happens with moisture in the next few weeks and I’ll post updates to my blog.
Very few have tried planting in this part of the State that I know of. Grateful for all of you who keep me updated on what’s going on through your questions and comments! In this week’s UNL CropWatch, Dr. Roger Elmore took the lead on an article addressing corn planting. The message is to ideally wait till soil temperatures reach 50F with weather conditions allowing soil temperatures to remain at 50F or higher for the next 48 hours. We’ve observed when seed was planted and a cold snap with cold rains was received within 48 hours, some problems with seed germination and emergence. Hybrids vary in cold tolerance and seed companies are a great resource for that information as to which hybrids could be planted first in colder soils. Soil temperature information can be found at the UNL CropWatch site at: https://cropwatch.unl.edu/cropwatchsoiltemperature. We’d also recommend you take the soil temperature in the field before you plant and can do so by using a meat thermometer.
Last year I remember receiving questions from April 21-24 regarding planting corn and soybeans with an anticipated cold snap later that week. At that time, I was recommending growers switch to soybeans. The reason? Soybeans imbibe (uptake) water more quickly than corn seeds and while we hear 48 hours to be on the safe side, the critical period is more like 24 hours. Also, several years of both small plot and on-farm research in Nebraska has shown the primary way to increase soybean yields is to plant early. Dr. Jim Specht’s research showed soybeans produced a new node every 3.75 days once V1 occurs. The nodes are where pods and seed occur. Our on-farm research planting date studies also showed regardless if the spring was cold/wet or warm/dry, the early planted soybean always out-yielded the later planted with a total average across trials of 3 bu/ac. The data ranged from 1-10 bu/ac. We never planted early without using an insecticide/fungicide seed treatment to protect that seed, so we recommend you add that if you do plant early.
Our recommendation would be to plant the last week of April or as close to May 1 as conditions allow. We’ve also seen good results after April 20 in years if the soil temperatures were around 50F with good weather conditions at least 24-48 hours after planting to maintain that soil temp. It’s important to know your level of risk, though. Crop Insurance planting date for replant considerations is April 25 and there may also be replant options from your seed suppliers. We never replanted any of our studies and I have only observed frost on soybean cotyledons one year where growers planted early with soybeans coming out of it. We had the largest number of acres I’ve seen planted by April 24 last year with thankfully no issues and they were able to take advantage of a high-yielding bean year. Perhaps this is something you wish to try for yourself this year? Consider planting some passes of soybeans early and come back with some passes three weeks later. You can use this Soybean Planting Date Protocol if you’re interested in trying this for yourself. Please let me know if you’re interested in this!
Depending on the number of acres you have, some growers are now planting soybeans first. Others are planting corn and soybeans at the same time by either running two of their own planters/drills or custom hiring someone to plant soybeans for them. This also spreads risk and can help with harvest. Regarding maturities, a study conducted at UNL East Campus compared a 2.1 vs. 3.0 maturity group variety at 10 day intervals beginning April 23 through June 19. Yield was highest for early planted soybean and a yield penalty of 1/8 to 1/4 bu/ac per day of delay in planting for MG2.1 and MG3.0 varieties, respectively was found. The study also indicated that yield of the MG3.0 variety was higher relative to the MG2.1 variety in early plantings (late April and early-mid May), but the opposite (greater yield in MG2.1 versus MG3.0 variety) was found for late plantings (late-May and June). In our part of the State, we’ve observed really high yields from strong genetics in the MG2.4-2.5 varieties when planted early; so I have a hard time automatically recommending later MG varieties without more data. Thus, I would love to work with anyone interested in planting early comparing a high yielding MG2.4-2.5 vs. a high yielding MG3.0-3.5 to obtain more data. Here’s a Soybean Maturity Group Comparison with Early Planting protocol to consider and please let me know if you’re interested in this!
Wheat: My colleague, Dr. Nathan Mueller in Dodge County, has taken the lead on
Nebraska crop reporting districts for wheat. The yellow area is considered ‘Eastern Nebraska’.
sharing wheat information for Eastern Nebraska. He’s put together an excellent resource on his blog at http://croptechcafe.org/winterwheat/. Every Friday he’s sharing an update called “What’s up this Wheat“. He also started an Eastern NE wheat listserv and his website explains how to subscribe to it. Grateful for his effort in this as we both have goals of increasing crop diversity in the areas we serve and there are many benefits to wheat in rotation!
Crabgrass prevention in Lawns: Just a quick note that while our Extension lawn calendars promote applying crabgrass preventer in mid-April, our horticulture experts say to wait till soil temperatures are 55F on a seven day average and we are currently far from that! Check out https://cropwatch.unl.edu/cropwatchsoiltemperature for soil temp info.
Beginning Soil Moisture 4-11-18
The current Drought Monitor shows 19% of Nebraska in the “abnormally dry” or “moderate drought” categories and in the shadow of large-scale drought in Kansas (97%) and Colorado (88%). Being curious about beginning soil moisture in non-irrigated situations, I installed Watermark soil moisture sensors in six non-irrigated, no-till locations in Webster, Nuckolls, Thayer, and Clay counties.
Nebraska map showing moderate drought (tan) and abnormally dry (yellow) areas of the state with locations of soil water sensors indicated by red stars.
Purpose
This quantitative information can be helpful as growers make planning and planting decisions. Granted, most planting decisions have already been made with inputs already purchased. Spring rains are also typically expected. However, information like this can help a grower be flexible in that planning should anticipated rains not be timely.
- The grower may choose to plant a more drought-tolerant crop like sorghum or a more drought-tolerant corn hybrid.
- A grower with livestock may choose to plant a feed/forage crop.
- A grower may choose to not terminate a growing cover crop such as rye, instead growing it for feed.
Process
Soil moisture sensors were installed at 1-, 2-, 3-, and 4-foot depths in non-irrigated, no-till corn and soybean residue fields near Byron, Superior, Lawrence, Bladen, and Clay Center. The sensors were connected to Watermark dataloggers from the Irrometer company. Because the default soil temperature on the dataloggers is 70°F, a temperature sensor is also installed to ensure correct calibration of the soil moisture. This is because soil temperature during this time is dfferent (much lower) than 70°F.
Any farmer or crop consultant could do the same for his/her fields to determine the same information and wouldn’t need the datalogger. Taking weekly readings at the same time each week, or even daily at the same time, would also give one an idea of beginning soil moisture. It’s best to allow at least 48-72 hours for the sensors to equilibrate to the current soil moisture conditions. This process is essentially the same as when sensors are installed for irrigation scheduling. The difference is these are non-irrigated fields with no current crop growing. For additional information and videos on using watermark sensors, please see the Nebraska Agricultural Water Management Network website.
Other Observations
Nuckolls County is shown as in “moderate drought” on the Drought Monitor. At the Superior location, we were hoping to also install into actively growing rye and winter-killed forage to determine beginning soil moisture in those conditions. The rye is currently 6 inches tall in the tillering stage and the soil probe wouldn’t go in the ground beyond 6 inches, so no moisture sensors were installed. The soil probe would only go in 12 inches in the winter-killed forage consisting of sorghum-sudan and radishes; thus, soil moisture sensors weren’t installed in that field either.
Results so Far
During installation, the 3- and 4-foot depths at all locations (only 4-foot at Clay Center) seemed very dry. The soybean residue appeared drier than corn residue. Two sites are located near Lawrence, one in corn residue and one in soybean residue across the road from each other. That data shows differences in moisture between different residue types the most clearly. I was unable to install to the 4-foot depth at the Lawrence soybean residue location. At most other sites, a hammer was used to help install to 4 feet. However, given the difficulty in installing the 4-foot sensor, these graphs do not show them as dry or drier than the 3-foot at any location other than Bladen.
This could be due to several reasons:
- The soil textural properties at 4-foot depth could have more clay and higher soil bulk density in which the drier conditions would not be obvious or easily determined just by installation difficulty.
- There could be a compacted layer.
- The dryness or wetness of any given soil layer at any given time is a function of various factors including the farming history of the field, previous several years of root development in different layers, previous year’s precipitation amount and distribution during the season as well as during off-season, evaporation rate, and water uptake pattern of the crop from different soil layers as water update from different soil layers varies and also varies with time during the season.
- The 4-foot layer may not actually be drier than the 3-foot layer.
Because only a few days of data are shown thus far, it is difficult to make a determination at this time. Data will continue to be collected until each field is planted and the results will be posted weekly on my blog. Additional information regarding each location is in each figure caption.
A special thank you to each farmer cooperating with me on this effort and to Dr. Suat Irmak for providing additional equipment and advice on this effort.
Soil moisture for top four feet in non-irrigated, no-till corn stubble near Bladen. Total soil moisture is currently depleted above 50% at this location. Notice even the second foot is above 50% depletion. The third and fourth foot follow the same line.
Soil moisture for top four feet in non-irrigated, no-till soybean stubble near Byron. Total soil moisture is currently depleted around 42% at this location. The second foot is also approaching 50% depletion at this site.
Soil moisture for top four feet in non-irrigated, no-till corn stubble near Clay Center. Total soil moisture is currently depleted around 30% for this location.
Soil moisture for top four feet in non-irrigated, no-till corn stubble near Superior. Total soil moisture is currently depleted around 30% for this location.
Soil moisture for top four feet in non-irrigated, no-till corn stubble near Lawrence. Total soil moisture is currently depleted around 37% for this location.
Soil moisture for top three feet in non-irrigated, no-till soybean stubble near Lawrence. Total moisture in these three feet is currently depleted around 37% for this location. Only three feet were installed as I didn’t have a drill to install the fourth foot.
JenResources 