From the Week of July 31, 2023
The one-stop-shop for everything you need to know about what’s happening this week in your fields.
This week’s featured agronomists are:
Courtney Wolf – Belle Plaine
Chris Soltau – Goodhue
Carly Reinke – Morristown
Gary Suess – Stewartville
Kirsten Bauer – Ellsworth
Scroll down to hear from your local agronomist, and click for contact info!
WEST
Belle Plaine – Le Center – Le Sueur
Courtney Wolf
This year bugs have been a constant battle in the alfalfa fields and now we are seeing them in some of the bean fields. There have been a few bean fields with enough aphids to warrant a spray. The threshold for aphids is 250 on one plant. To find aphids start looking on the edges of your fields, near any brush or tree lines. You will see them most on the underside of the newer leaves on the plant. The other insect that has been appearing this year is spider mites. You will most likely find these on fields that have not had as much rain and might have some sandy or clay pockets. They will start anywhere where the soil is dry. If you have questions about the insects in your field and what insecticides you should be applying contact your local Ag Partners Agronomist.
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EAST
Pine Island – Cannon Falls – Goodhue – Lake City
Chris Soltau
Cover crops are one of the buzz topics in agriculture. If one wants to plant cover crops, I like them planted no later than October 15th. They will have the chance to grow to protect against soil erosion and maintain microbial activity longer in the soil to have more of them to help us in the spring. Cover crops also help with sequestering nitrogen, increasing carbon through more biomass. After October 25th soil microbes and ground temperatures drop to below 50 degrees, reducing microbial activity and plant growth. The average frost date for our area is October 7.
Everyone thinks cereal rye is the best thing for cover crops. It’s easy to grow, has growth in the spring to make it seem like it wasn’t a waste of time and resources, and it is low cost. Below are excerpts of articles from Iowa State, Nebraska, Indiana, and Minnesota which reinforce my observations over the years.
“Rye mulch delays soil warming and drying, ties up nitrogen, and may act as a ‘green bridge’ for plant pathogens to go from dying rye to the corn seedling. These are the bad things about rye.”
Here are my suggestions on what to do if you planted cereal rye that you are not going to harvest for feed. Terminate the rye as soon as possible. 2-3 weeks before planting is best but do not let it get taller than 10”. If short and you plant into the rye, terminate within 2-3 days.
Add 30-40#N as starter fertilizer. Only 10% of the nitrogen assimilated by the above ground portion of the rye will be available to the corn. If the rye is above 8-10” tall when terminated, increase your N rate 10% to compensate for the nitrogen tie up. Split applications of nitrogen are preferred in the data.
Table 1. Effect of termination treatments of a winter rye cover crop on corn seedling growth, root disease at growth stage V2 to V3, barren plants at R6, and yield in Iowa.
Other small grains and cover crops that die in the fall are a good option also. The earlier the rye is terminated, the less problems you will have. It’s all about saving the soil from erosion, sequestering nitrogen, and having more microbes in the spring.
CENTRAL
Morristown – Wanamingo – Kenyon
Carly Reinke
With fungicide wrapping up that means we are one step closer to harvest! Fertilizer is a thought on everyone’s mind when we talk about fall. Variable rate fertilizer is a great return on investment as we use grid sample results to make fertilizer recommendations that ensure adequate nutrient levels across the entire field. This is done by putting a higher fertilizer rate in the low nutrient level spots and a removal rate in the adequate to high nutrient level spots.
The phosphorous rec has an average rate of 188 pounds per acre with a minimum of 100 pounds and maximum of 250 pounds. The potassium rec has an average of 220 pounds per acre with a minimum of 100 pounds and maximum of 250 pounds as well. This is very similar rates to a flat rate spread you would normally see but with this rec you can see from the photos above that there is more product in the areas with lower ppm. This allows you to build your fertilizer levels with the highest return on investment. We also tend to see yield bumps in some spots of field which is something we need to consider when we build future recs between grid samples.
If you are interested in trying VR Fertilizer or are ready to start talking about your recs for crop year 2024, contact your local Ag Partners Agronomist/AYS Specialist!
SOUTH
Elgin – Lewiston – Stewartville
Gary Suess
As we enter the first week of August, fungicide applications are ongoing in both corn and soybeans. However, we’re getting to the point in the growing season where we’ve done everything we can to help our crops and we’ll be depending on Mother Nature to take us the rest of the way to maturity.
For my first weekly agronomy update back in early May, I visited a corn field that was one of the first planted in our area (April 11th). We had a very warm week after Easter where we saw some corn get planted, that was followed by a cold, damp stretch that had many wondering if the corn would emerge or not. As we enter the ear development phase I thought it would be interesting to review some of the weather dynamics affecting this field, what impacts it had on this field, and see how the crop has fared in this challenging year.
Let’s take a look at two factors affecting the growth and development: GDD & accumulated precipitation throughout the season. This first chart shows the accumulated GDD for this year and compares it to each previous year back to 2018. Overall, we’ve had very good warmth this year which has helped the crop advance nicely. When comparing the years, 2023 is sitting right in the middle of the pack, putting us right on track for a mature crop come harvest time.
Accumulated/limited rainfall is another story that I believe all producers throughout the Ag Partners territory are experiencing. Here are two charts comparing 2023 rainfall patterns with previous years. The first chart shows cumulative precipitation, including from snow melt. When comparing the years, 2023 is overall trending to the bottom of the list. However, when looking at the beginning of the growing season, 2023 was towards the top of the list because we had a decent soil moisture recharge from the snow melt.
The second rainfall chart shows a different story. It plots out the monthly precipitation for each month of the growing season. Consistently, 2023 was on the lower end of monthly precipitation, especially during June and July, the months with higher moisture requirements. I believe the higher soil moisture recharge provided from the winter snow melt has served us well to help the crop persist the dryer climate we’ve experienced this growing season.
Finally…so how did the field planted on April 11th, turn out to this point? Here’s a picture of 3 ears pulled from the field. At this point, the corn looks amazing and is withstanding the dry conditions very well. I believe this performance is a testament of modern hybrids to perform in these adverse conditions. Ultimately, rainfall in August will determine the final outcome for this corn. Best of luck to everyone for the rest of this growing season, I hope you all receive good rainfall to get us to maturity!!
< DKC56-65 RIB; 20 rows around x 38 kernels long
WISCONSIN
Ellsworth
Kirsten Bauer
Click to learn some fun facts on our favorite crop, corn!