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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 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

JenREES 4-8-18

Reducing Soybean Seeding Rates:  Can I reduce soybean seeding rates and still maintain yield?  It’s a common question from soybean growers, especially those seeking to reduce input costs.  Every year during winter meetings I share what our growers have found.  We now have 11 years of On-Farm Research proven data.

The findings? Reducing soybean seeding rates from 180,000 or 150,000 seeds/acre to 120,000 seeds/acre doesn’t statistically reduce yields in 30- or 15-inch rows in silty clay loam and silt loam soils in south-central and eastern Nebraska. Results of 18 studies showed for seeding rates of 180K, 150K, and 120K seeds per acre, average yields were 69.0, 68.7, and 68.4 bu/ac, respectively (Figure 1). The early studies within this dataset all had seed germination of at least 90% listed on the seed bag. In all but two situations (seeded at 180,000 and achieving 88% germination), the growers were able to achieve 90% or greater of their planted stand.

Graph of yields from 18 soybean population studies

Figure 1. Yield results of on-farm seeding rate studies from 2006 to 2017 (15″ and 30″ rows). Average final stands: 90,000 = 83,067 plants per acre (ppa); 120,000 = 106,863 ppa; 150,000 = 132,700 ppa; and 180,000 = 157,924 ppa

 

 

 

 

 

 

 

 
As I share this data, I’ve often heard “but I seed higher rates because of X, Y, or Z…”; however, this dataset includes a lot of those reasons without negative yield consequences!  I’ve worked closely with these studies in walking the fields; taking notes and pics; counting plants, pods, and seeds; so I’m really confident of the research and the fact that soybeans truly compensate for reduced populations!  Outside of this research, I’ve also observed this in many soybean hail, crusting, and PPO inhibitor seedling damage situations.  This dataset includes:

  • The latest soybean varieties as the research was conducted from 2006-2017.
  • Erect and bushy type varieties in growth architecture.
  • Higher and lower yielding situations.
  • Fourteen irrigated fields and four non-irrigated.
  • Hail events occurring from cotyledon stage to R2 in some of these fields.
  • Crusting in some non-irrigated fields.
  • Seed treated in some fields and others without (determined by grower’s planting date).
  • In some years, pod and seed count data were also collected; the data showed similar numbers of seeds/acre and ultimately yield per acre.
  • Observations of increased plant branching at lower seeding rates and difficulty in telling the seeding rate treatments apart as the season progressed.

Our research data for 11 years shows no statistical yield differences in seeding rates from 120,000-180,000 seeds/acre in 15- or 30-inch rows in silty clay loam or clay loam soils.  Thus, reducing seeding rates is a way to consider reducing input costs for 2018 without impacting your yield.  If you dropped your seeding rate from 150,000 seeds/acre to 120,000 seeds/acre, you could save $10.08/acre, assuming a yield loss of 1 bu/ac, a seed cost of $60 per 140,000 seeds, and a savings of $25.71/ac on seed.

  • Thus, if you plant between 140,000-160,000 seeds/acre, consider dropping your seeding rate to 120,000 and aiming for a final plant stand of 100,000 plants/ac based on our research findings.
  • If you plant at 180,000 or more seeds/acre, consider dropping your seeding rate to 140,000 seeds/acre as a step-wise increment.

Still hesitant? Consider trying this yourself for your location!  Consider using either this Two Population Treatment Design or Four Population Treatment Design.  You also can download the Nebraska On-farm Research app, available in Apple and Android, to help you set up your plot design to obtain scientific results. If you have questions or need help setting up your research project, please contact me or anyone involved with our Nebraska On-Farm Research Network.  To view all the graphs and additional data regarding 15″ row spacing with reduced seeding rates, please check out this week’s UNL CropWatch at http://cropwatch.unl.edu.

Beginning Soil Moisture:  On Good Friday, I installed soil moisture sensors down to 4′ in SoilMoistureTwitterPicnon-irrigated no-till fields at Bladen and Lawrence.  Last week I added three more sites at Clay Center, Superior and Byron.  Thus far, the 3′ and 4′ are dry in all those locations other than Clay Center (only dry at 4′).  At Superior, I could only get the soil probe in the ground 6″ into actively growing rye and 1′ in cover that winter-killed.  I was just curious what kind of moisture existed currently in the southern tier of counties.  I realize planting plans are in place and that we often receive rains in April/May.  Hopefully it provides information that can be helpful in how to use that soil moisture.  If we don’t get necessary rains, you may consider switching to a different crop, growing feed if you have cattle, or not terminating actively growing rye as originally planned but perhaps using it for feed.  Will share graphs next week and I appreciate the growers allowing me to install these in their fields!

Center Pivot Irrigation Short-Course

Hope to see you in Clay Center on February 11 for this upcoming meeting!
(Please click on the picture to enlarge the text.)

Center Pivot Management Short Course

Soil and Water Conference

Hope you can join us for our Soil and Water Conference tomorrow in Clay Center!

Soil and Water Conference

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