Soybeans in East Central Nebraska have reached early R3

It is summer again in full force, humidity and heat!  Makes for soybeans and corn to grow with near maximum heat units everyday accumulation.  This report is from our July 2nd field data gathering trip.

April 2021 Demo Tractor and Orthman-Deere DR planter planting soybeans at High Plains Vo-Ag plots near Polk, Nebraska Tractor and Planter courtesy of AKRS John Deere

Today we wanted to inform you of some interesting findings from Mick Goedeken and my investigating and checking plants in our plots where we have five different populations at the High Plains High School FFA plots on our hosts farm – Rod Hanquist.  We planted these Pioneer “Plenish Oil” variety beans at 60K, 80K, 100K, 120K and 140-150K.  Our study with the students at the Polk, Nebraska High School FFA Chapter is to observe efficiency, growth, yield and water use in the different populations.  Both Mick and I have our ideas on plant populations for growers in Nebraska on 30 inch row systems and we are watching through this year what will pan out as the population changes compete for space and sunlight at low populations compared up to a common recommendation of 150,000 seeds dropped.

Our data in the graph below indicates a few interesting details.  We counted the individual nodes where flowers then pods emerge on all branches of the plants, we measured height to the top of the last exposed trifoliate bunch exposed in centimeters (SI).  You can convert by dividing the given height by 2.54 and then results will tell you inches.  Also we counted the number of branches which indicates how much root space is there and how the plants respond to “breathing room”.  You know — extend the elbows wide and breathing deep.

Fig. 2 Soybean Population Trials 2021

Let me offer some explanation to what you are seeing.

The plant number bars on the visual graphic indicate the number of plants we observed per rep as we zig-zagged through the trials to randomly look at plants from north to south in these five populations.  That way there was no “cherry picking”.  Then from left to right on the chart is the differing populations.  The taller bars are the height in centimeters and you can see the 60K and 80K on average are the tallest plants of the field.  The purple bar is an average of the three reps of data.  The yellow number indicates that average value.  46.6 cm is 18.3 inches tall and so on.

So as population increases the height changes downward some but close to the same as the low population plots.  Now llok at the three columns of each population trial for the number of nodes (27.6, 24.5 and so on left to right).  The lowest population of 60K is 10.9% more than 80K and compared to the 150K plots the 60K pop plants have 46.7% more nodes at this time on July 2nd.  Comparing the number of branches in the 60K plot to the 150K plot we see a 28.8% increase in branch numbers.

It is our opinion at this juncture of the soybean plants life that the lower populations from the standard 150K population which ended up as a final population of 132K-136K may yield well because of the higher number of branches which in turn exposes more nodes for pods to develop.

You are up to date with some of what is happening at the Orthman Research activities near Polk, NE.  We will keep bringing more from the field as days progress here.  It is our intention to keep you abreast of the work being carried out both at the McNaught Farm and at the Hanquist site as a strip till system aids crop growth above and below ground.