Regional Crop Update: September 2 - September 15, 2020

September 16, 2020 11:40 AM
Blog Post

While drought is still widespread, rainfall blanketed most of the state last week, providing some welcome relief to pastures, hay fields, newly-seeded cover crops, and later maturing soybeans. The rainfall caused some standability concerns with corn. Other issues noted by field agronomists include the start of harvest, harvest safety, cover crop seeding, and improvement in the condition of hay and pasture. Read on for more specifics for what’s happening in different regions across the state.

accumulated precipitation


Northwest Iowa

Joel DeJong (Region 1): “Most of the corn silage harvest has been completed, and I know of three soybean fields that have been harvested so far. As the week continues, I am certain more harvest will occur. Rain was well under an inch in total last week to the north, maybe an inch and a half as you go south in this region. Some cornfields are beginning to have standability issues, so be certain to check and prioritize harvest order. As harvest begins, be certain to check your equipment every day to insure that all lights are working, and safe harvest practices are implemented."

Paul Kassel (Region 2): “Corn and soybean crops continue to reach maturity at a rapid pace. There was some much needed rainfall across the area from September 8-12. There were also some high winds in northern Kossuth county that caused some severe corn lodging. The US Drought Monitor shows a wide range in soil moisture in my 10 county area. Most of Winnebago county and northern Kossuth county have received normal rainfall amounts for August. However, most of Sac county, and parts of Buena Vista and Pocahontas county are in D3/extreme drought. Most of the rest of the area are in D2/severe drought or D1/moderate drought. Corn and soybean harvest will likely start later this week. Some corn has been harvested and is testing about 20% grain moisture."

Hancock county soybean field
Recent rainfall has helped this field in Hancock County reach maturity at a more normal pace. Photo by Paul Kassel.


Central Iowa

Meaghan Anderson (Region 7): “Central Iowa received significant rainfall and cooler temperatures last week, which was a welcome sight for anyone with pastures, hay, or cover crops already seeded. Most corn fields are mature (R6) and some have developed standability issues after last week's rain. It will be important to prioritize fields that will be harvested to preserve yield and avoid additional harvest delays with downed corn due to stalk rot issues. Soybean fields are quickly reaching maturity, with most being too far along to benefit from the rain. Harvest of both corn and soybeans has started. Phone calls in the last two weeks have been primarily about cover crop species choice, management of downed corn, and the prospect of seeding corn in derecho-affected fields next year."


corn kernel development varies depending on type of injury from the derecho
Corn kernel development was affected by the derecho. Upper left ear was from a plant still standing, upper right was from one bent over, and bottom ear was from one pinched over. Photo by Meaghan Anderson.

East Central, Southeast, and South Central:

Virgil Schmitt (Region 9): “Rainfall over the last eight days in the counties I cover ranged from three to over eight inches, with the heavier amount roughly north of Highway 92. In general, temperatures last eight days in the counties I cover were one to three degrees below normal. Most corn fields have reached or are within a few days of reaching R6 and are generally looking good, except for storm damaged fields. The cool weather last week slowed the rate of maturity. Soybeans are mostly R6 to R8. In general, they also look good. Cover crops and dealing with derecho-related issues continued to be common topics of discussion last week."

temperature departure from normal

Josh Michel (Region 11): “Scattered showers delivered 3 to 5 inches of rainfall across most of the region. Thankfully, most of the rainfall came over a spread of 4 to 5 days, allowing many soils to start recovering from drought conditions we experienced most of the summer. Most corn fields are at late dent stage to full black layer. Silage harvest had been occurring and was mostly completed before it started raining. I expect silage harvest to finish up and combining to start in many fields later this week. Soybeans are generally around early to late maturity, with some fields having already dropped all their leaves. Soybean harvest may start by the end of the week in some fields. Alfalfa and pastures are coming back nicely after the much needed rainfall and cooler temperatures. Most of the recent field calls and questions have centered around nitrate testing and fall seeding for alfalfa fields, pastures and cover crops.”


Check out the map below to find your local ISU Extension field agronomist and find their contact information here!

Field agronomist location map


Meaghan Anderson Field Agronomist in Central Iowa

Meaghan Anderson is a field agronomist in central Iowa and an extension field specialist at Iowa State University Extension and Outreach. Educational programming is available for farmers, agribusinesses, pesticide applicators, certified crop advisors, and other individuals interested in...

Rebecca Vittetoe Field Agronomist in EC Iowa

Rebecca Vittetoe is an extension field agronomist in east central Iowa. Educational programs are available for farmers, agribusiness, pesticide applicators, and certified crop advisors.

Areas of expertise include agronomy, field crop production and management of corn, soybeans, and...