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JenREES 8-5-18

Thank you to all who made the York County Fair go so smoothly! It’s always a joy to see the 4-H and FFA youth and families rewarded for the hard work they put into their projects!

Crop Update: I didn’t get out to the field much this week with fair but did spend a few

IMAG5589

Bird cherry oat aphids on ear husks and green leaf aphids on leaves of plants in this non-irrigated field. Lady beetle larvae predators also present.

hours one afternoon. There are portions of the area I serve that have been blessed with rains and look really good. The main thing that I’m seeing a lot more of this week is aphids in corn fields. This can be common in fields where fungicide is applied as the fungicide kills a beneficial fungus that attacks aphids. Some aphid species are also attracted to moisture stressed crops. The heat has also pushed the crop along quickly. We have another yield forecasting article in this week’s CropWatch at http://cropwatch.unl.edu where we talk about the impact of the heat on yields. As of right now, based on comparing this year to 30 years of weather data, it’s appearing corn may reach maturity 1-3 weeks early. Irrigated yields are estimated to be near average and above to near average for non-irrigated corn (where drought is not a factor).  These yield forecasts are based on simulations under ‘perfect conditions’ (with no nutrient loss, disease etc.) but they can give us an indication of what may happen if we continue with higher heat conditions.

 

Unfortunately, pockets in the area continue to miss rains. The drought monitor still is not

IMAG5559

Drought-stressed soybean field.

reflecting the drought in this part of the State; at this point, I’m unsure what else either Al Dutcher or I can do about this. One farmer reminded me drought occurred in the same area in 2006, 2012, and now 2018-six years apart each time. Driving the area, hardest drought-stressed crops really took a turn this past week with corn in hard dough to early dent with some kernel abortion and soybeans are beginning to abort pods and quit filling seeds. One question has been on weighing taking corn for silage or not. If you have at least an estimated 50 bu/ac grain in most of the field other than highly compacted areas, it may be more profitable to keep for grain (unless you’re looking for cattle feed). The following are some resources to consider further:

Dicamba: We’ve often mentioned the research showing a soybean plant producing a new node every 3.7 days upon reaching V1 stage. And, I’ve used that in the forensics assessment for determining a timing for off-target dicamba movement. One question I’ve had was “Do soybean plants continue to produce a new node every 3.7 days upon being affected by off-target dicamba?” My assumption in the forensic analysis I have used is that a new node continued to be produced every 3.7 days in spite of off-target dicamba. However, the only way to really test this would be to have the same soybean variety in both an Xtend and non-Xtend version. We will release a CropWatch article next week in which a situation like this occurred at the Eastern NE Research and Extension Center. Dr. Jim Specht counted nodes in both the non-Xtend variety with off-target dicamba and the Xtend variety that wasn’t affected. He found the same number of nodes in spite of the dicamba affected non-Xtend variety being shorter in height and having less canopy. So that in itself is good information for use in forensic assessments. However, he also found plants in which a higher off-target dicamba dose affected the top-most growing point. When that occurred, the number of nodes was affected.

Last year, a group of us released a dicamba survey during Soybean Management Field Days. Reminder those are upcoming this week (https://enre.unl.edu/soydays)! The survey helps us understand your perspectives about dicamba and this year we’ve added questions regarding using Xtend technology. Hopefully it will provide helpful information for all of us and the results will be shared via CropWatch and winter meetings.  We’d encourage and be grateful for any soybean growers to participate at: https://www.surveymonkey.com/r/JWDCY3C.

South Central Ag Lab Field Day: Please hold August 29, 2018 for UNL’s South Central Ag Lab (SCAL) Field Day near Clay Center! Attendees can choose which sessions you would like to attend. Options include the latest SCAL research in the areas of Irrigation/Water Use; Nutrient Management; Weed, Disease, and Insect Management; Cover Crops; and Cropping Systems. CCA credits will be available and there’s no charge to attend. Will have more specifics for you next week but please hold the date for now!

Vine Crop Problems: The following resource explains options for diagnosing various problems with cucumbers, squash, and melons: https://hortnews.extension.iastate.edu/2011/8-24/cucurbitwilt.html.

 

Soil Moisture 7-11-18

drought monitor 7-10-18

Drought monitor as of 7-9-18.  From the moisture graphs below, I don’t agree that at least portions of Nuckolls and Thayer counties were removed from drought status and other portions of our region no longer show abnormally dry.  Even though we were blessed with some large rain events, the moisture really helped only the top two feet of the profile since in areas of this region, the soil moisture status had never fully recharged at the 3 and 4 foot levels.  I did not provide graphs last week for groundtruthing as I took a few days off over July 4th.  We will see how or if this is adjusted in the future.

Byron 7-11-18

This location received 1″ prior to 6/29 since the last graph and ? on July ? Total soil moisture depletion for this location (top 4 feet) is around 30% depletion based on this graph.  The third foot is actually hard and dry compared to how wet it showed the past several weeks on these graphs, so I’m unsure if there’s an old root or earthworm channel that’s been keeping the sensor reading wetter than what I actually probe.  But it is now drying back out in this graph.  Corn at this location is pollinating.

Superior 7-11-18

Total rains received since the last graph are ? Total soil moisture depletion (top 4 feet) is at 50%.  Corn at this location was three leaves from tasseling on 7/11.

Lawrence 7-11-18 Corn

Since the last graph, this location has received ? of rain.  Total soil moisture depletion (top four feet) in this field is at 50% depletion.  Soybean at this location is nearing beginning pod.

Lawrence 7-11-18 Soy

Rains received since the last time I showed graphs are ? Total soil moisture depletion (top three feet) is showing above 50% depletion.  Corn at this location is pollinating.

Clay Center 7-11-18

This location has received some rains and current total soil moisture is around field capacity for this field.  Corn is pollinating at this location.

Seward 7-11-18

This location has been blessed with rains.  It wasn’t difficult to install these sensors and the total depletion (currently showing top three feet) around 30% depletion.  I hadn’t hooked up the fourth foot sensor yet, thus why no readings are shown this week for it.  Corn is pollinating at this location.

York 7-11-18

This location received 4.5″ of rain on ? which helped with the top two feet of the profile.  An additional ? was received on July 1.  Since then, no significant rainfall has been received at this location with the soil moisture depletion (four feet total) around 35%.  Soybean is at beginning pod at this location.

Soil Moisture 6/7/18

drought monitor 6-7-18

Nebraska drought monitor map released 6/7/18.  18.1% of State is abnormally dry (yellow) with 5.4% of the State as moderate drought (tan).

Byron 6-7-18

Corn is at V7 in this field.  The third foot sensor started reading strangely-very wet.  The third foot profile is dry but sensor not showing it-thus the total soil moisture is not reflected as dry in this graph as it truly is.  This location received 1.33 last week.

Lawrence 6-7-18 corn

I had re-installed the 2 foot sensor in this field and it is showing how dry the second foot has quickly become.  The same is seen across the road in the soybean stubble.  0.88″ was received at this location in the past week.  Soybeans in this field were at V1 on 6/7/18.  This farm family mentioned that first alfalfa cutting was 1/2 of normal this year.

Lawrence 6-7-18 Soy

Corn in this field was at V5 on 6/7/18.  The soil profile in the top foot is drier compared to in the corn stubble across the road-which has been typical all year.  Total soil moisture depletion in this field right now is around 50% for top three feet.

Superior 6-7-18

This location was blessed with some rain!  1.35″ was received 6/2/18 and another 0.50″ the morning of 6/7/18.  The top two feet truly are muddy in this field when probing the soil but moisture runs out about 2.5 feet down into the profile.  Corn was at V5 at this location on 6/7/18.

Soil Moisture 5-17-18

Hoping these graphs change for us after this past weekend’s rain events!  These readings were taken as of 5/17/18.

Byron 5-17-18

As of 5/17/18, total soil moisture depletion in this field stayed fairly steady.  The top two feet are nearing field capacity.

Superior 5-17-18

At the Superior location as of 5/17/18, total soil moisture depletion remained around 40%.  The first foot is nearing field capacity with the second foot nearing 35% depletion.

At the Lawrence location I’m just sharing last week’s graphs from 5/10/18.  Soybean was planted into the corn stubble on 5/11/18 and the sensors were removed and re-installed with the readings needing time to adjust.  The farmer said it was so dry he had to use a drill to re-install the moisture sensors.  I have no idea what happened in the soybean stubble field but the readings this past week were crazy so decided to share new graphs on the Lawrence location next week.

Lawrence 5-10-18 CornLawrence 5-10-18 Soy

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.

Bladen 5-10-18

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.  

Byron 5-10-18

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.

Lawrence 5-10-18 Corn

This site continues to remain steady with total soil moisture depletion around 35%. 

Lawrence 5-10-18 Soy

The first foot sensor has leveled off after being reprimed on 4/26.  Total soil moisture depletion (1-3′) remains around 45%. 

Superior 5-10-18

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%.

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.

Drought Monitor 5-1-18

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.

Bladen 5-3-18

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.

Byron 5-3-18

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.

Lawrence 5-3-18 Corn

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.

Lawrence 5-3-18 Soy

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%.  

Superior 5-3-18

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.

Drought Monitor 4-26-18

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.

Bladen 4-26-18W

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′).

Byron 4-26-18

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.

Clay Center 4-26-18

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.

Lawrence 4-26-18 Corn

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.

Lawrence 4-26-18 Soy

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.

Superior 4-26-18

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.

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.

Nebraska map

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.

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

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.

Bladen

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.

Byron

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.

Clay Center

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.

Superior

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.

Lawrence corn

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.

Lawrence Soy

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.

Crop Update 8/1/14

Southern rust of corn confirmed in Clay County July 31.  This was found on one leaf in a field near Trumbull.  Just because southern rust has been found in the area, we don't recommend automatically spraying.  Scout your fields and consider disease pressure, growth stage, and economics.  Long season corn and late-planted fields have the potential for most damage.

Southern rust of corn confirmed in Clay County July 31. Very small, tan-brown lesions on upper surface of the leaf, usually in clusters.  Spores inside the pustules are typically orange.  This was found on one leaf in a field near Trumbull. Just because southern rust has been found in the area, we don’t recommend automatically spraying. Scout your fields and consider disease pressure, growth stage, and economics. Long season corn and late-planted fields have the potential for most damage.  Secondary common rust sporulation has also been confused as southern rust as the secondary pustules tend to look like this.  It’s important to obtain microscopic confirmation to know for sure if you have southern rust in your fields.

Spores of southern rust appear elongated vs. common rust appear as near perfect circles.

Microscopic Observation:  Spores of southern rust appear elongated vs. common rust appear as near perfect circles.

Another common problem is old common rust lesions being confused as gray leaf spot.  The color of this lesion is a tan-gray, typical of gray leaf spot.  Using backlighting or a handlens, you can see the pustules within this lesion confirming it is common rust and not gray leaf spot.  I've had many calls that gray leaf spot was up the entire plant in their fields and after looking at fields, have found it to be common rust in most situations.  It's important to know what disease you truly have to make the best decision on fungicide application.

Another common problem is old common rust lesions being confused as gray leaf spot. The color of this lesion is a tan-gray, typical of gray leaf spot. Using backlighting or a handlens, you can see the pustules within this lesion confirming it is common rust and not gray leaf spot. I’ve had many calls that gray leaf spot was up the entire plant in their fields and after looking at fields, have found it to be common rust in most situations. It’s important to know what disease you truly have to make the best decision on fungicide application.

Have also received questions on soybeans, particularly in dryland.  Soybeans are drought stressed-often showing it in pockets within dryland fields right now.  Closer observation shows plants aborting pods and losing lowest leaves.  Spidermites can also be viewed on leaves in some of these patches.

Have also received questions on soybeans, particularly in dryland. This photo is showing drought stressed soybeans-often occurring in pockets within dryland fields right now. Closer observation shows plants aborting pods and losing lowest leaves. Spidermites can also be viewed on leaves in some of these patches.

Dryland corn showing stress as well.  June rains were making for dryland crops with potential, but also led to shallow rooting.  Crops could use a drink right now....but would prefer no more ice and hail.  The storm that hit Clay County so hard occurred one year ago today.

Dryland corn showing stress as well. June rains were making for dryland crops with potential, but also led to shallow rooting. Crops could use a drink right now….but would prefer no more hail and tornadoes. The storm that hit Clay County so hard occurred one year ago today.

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