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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.

Cow-Calf College

This looks like an excellent workshop for anyone in cow-calf production.  Hope to see you there!
(Click on the agenda below to enlarge the view).

Cow-Calf College

Storm Damaged Crops

The rain was welcome on Thursday but the wind and hail damage that came were devastating to a good portion of theSeverely damaged corn County.  I’m so sorry to all of you affected….for some of you, this is two years in a row of severely hail damaged or totaled out crops.  We are thankful the damage wasn’t worse.  You can see more pictures here.

So the big question is what do you do now?  Ultimately, each field will need to be assessed on a case by case basis.  The following are our NebGuides for hail damage to corn and soybeans.  For the most part we were in brown-silk to blister for corn and late pod-beginning seed in soybean (R4-R5).  The concerns I have right now are stalk quality, disease, grain filling, and the amount of diseased grain we may have due to mushy areas on hail-damaged cobs right now.   Several years ago, we watched how severely hail-damaged corn a little later in the season turned brown and died.  We also know that southernCorn ears damaged by hail that are turning mushy. rust is in the area and while much of the leaf tissue in the County is damaged, it is still in the County in other fields and south of us.  The Puccinia polysora fungus that causes southern rust, when severe enough, will infect and cause pustules on the stalks.  With the wounding and low leaf area for photosynthesis, stalk strength is a concern and fungicides may be a consideration depending on potential yield loss-again need to assess on a field by field basis.

I talked with a number of people on Friday regarding thoughts on silage, green chop, haying/baling, planting cover crops, etc.  Dr. Bruce Anderson, UNL Extension Forage Specialist, said the most common salvage operation for corn damaged by hail, wind, drought, or other calamities is to chop it for silage.  Don’t be in a hurry, though.  Standing corn currently could be over 80 percent moisture.  The easiest way, and maybe the best way, to lower moisture content is simply wait until some stalks start to turn brown.  Waiting also allows surviving corn to continue to add tonnage.

But in some of our damaged fields, I don’t think we can wait to make silage.  Bruce also shared you can reduce moisture by windowing the crop and allow it to wilt one-half to one full day before chopping.  You also could mix grain or chopped hay to freshly chopped corn to lower the moisture content.  It takes quite a bit of material for mixing though – about 7 bushels of grain or 350 pounds of hay to lower each ton of silage down to 70 percent moisture from an original 80 percent moisture.  That’s 7 bushels grain or 350 pounds of hay for each ton of silage.

Or, you can allow that windrowed corn to dry completely and bale it as hay.  Be sure to test it for nitrates before feeding.   Grazing might be the easiest way to use damaged corn, and this is a good way to extend your grazing season.  You might even plant some corn grain or sorghum-sudangrass or oats and turnips between rows to grow more forage for grazing if you can wait until late fall before grazing.  Be sure to introduce livestock slowly to this new forage by feeding them before turning in to reduce the chances of digestive problems.  Also, strip graze the field to reduce trampling losses and get more grazing from the corn.

Gardening in Drought

As I set here writing, we went from wearing t-shirts yesterday to receiving freezing rain and sleet today!  The precipitation is much welcomed and it’s nice to see spring bulbs coming up and the grass turning green!  But we’re unfortunately not out of the woods yet regarding this drought, and may not be for some time.

This Thursday, April 11, Elizabeth Killinger, UNL Extension Educator in Hall County, will be talking to us about gardening during drought.  Come enjoy an evening of learning about drought-tolerant plants and ideas for your landscape!  The evening begins with a light supper at 5:30 p.m. and we plan to be finished around 7:00 p.m.  There will be no charge for this workshop, so please come and invite your friends and your youth who enjoy gardening as well!

Also, if you would like to bring some plants for exchange, you are welcome to do so and share with others!  Please call the Clay County Extension Office at (402) 762-3644 or Jenny at jrees2@unl.edu to let us know you’re coming so we can plan for the meal.  See you then!gardening in drought

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