Regional Update: September 2023

September 12, 2023 2:27 PM
Blog Post

After about a month of minimal rainfall across the state, some much welcomed rain fell over the weekend and on Monday, September 11. The couple of hot weeks and dry conditions in August really pushed crops along across the state, even causing some to reach maturity prematurely. Silage harvest is wrapping up in many areas, and farmers are starting to hit the fields to combine. As we wind down the growing seaosn, stalk quality concerns in corn, seeding cover crops in dry conditions, soybean diseases like white mold and sudden death syndrome are some of the issues ISU Extension and Outreach Field Agronomist have observed or had questions on as of late. Read on for more specifics on what’s happening in fields across the state.  

Observed rainfall totals across the state for the last two weeks (August 29 - September 12, 2023). Source: National Weather Service

Northwest Iowa

Leah Ten Napel (Region 1): “We received variable amounts of rainfall across my territory this past weekend, ranging from nothing to 0.6 inch. Silage harvest is finished up for the most part, and growers are starting to harvest corn. I am hearing moistures as low as 19%, and also high moisture corn being harvested. Soybean fields in the area are at varying maturity levels, some fields look like they could be harvested within the next 2 weeks. Yield estimates coming in from corn are ranging from 100 to 250 bushels per acre. I have not heard estimates on soybean yields yet but assume they will be lower this year due to lack of August rainfalls and late season pests. Pastures have been slow to grow back but seem to be handling stress well in the last month. Dry field conditions increase the potential for combine and field fires during harvest. Check out this article on Fire Prevention and Safety Tips During Harvest. Wishing everyone a safe harvest season!”

Northeast Iowa

Josh Michel (Region 5): “Aside from Dubuque County, most of NE Iowa has received very little precipitation over the past two weeks. That being said, most of the region has received anywhere from 0.10 up to 0.25 inch; while areas in Dubuque County have received up to 1 inch or slightly more. As the latest U.S. Drought Monitor shows, we’ll gladly welcome any moisture we’re able to receive. Above average temperatures and limited soil moisture have pushed many crops to maturity over the past two to three weeks. Corn silage harvest is finishing up, while grain harvest has started in a few isolated areas. Concerns about nitrate levels in corn being harvest for silage has been a common question, especially with drought-stressed corn. Early grain harvest reports have indicated widely variable grain moisture and yields. Stalk quality and standability may become a concern as fields are allowed to dry down. Soybeans are generally late R6 to R8. While some soybean fields are still in the final stages of filling pods, others have reached full maturity. Isolated pockets of disease continue to pop up, as drought conditions continue to persist. Forages continue to suffer in areas where rainfall has been deficient. Many pastures and alfalfa fields have seen very slow regrowth. Fourth crop alfalfa is taking place in some areas that have received ample rainfall over the past few weeks, but generally many producers will forgo taking a fourth cutting this fall. Other field calls over the past couple weeks have centered around silage nitrate concerns, forage management, fall weed management in pastures, fall fertilizer plans, and seeding cover crops.”

Central Iowa

Meaghan Anderson (Region 7): “All of central Iowa received rainfall over the weekend, but the totals south of I-80 were over a half inch and north of I-80 were generally less than a half inch. This rainfall did very little for row crops but will be beneficial for pastures and adding some soil moisture back into the reserve. Importantly, the soil moisture will be very helpful for those wanting to do fall soil sampling, since dry soils can create issues for test interpretation. Most corn and soybean fields are nearing maturity rapidly if they’re not already there. I’ve received several harvest reports so far on corn – corn is mostly wet, yields are relatively good, test weights are a little lower than we’d like to see. I am still receiving reports of tar spot, but we expect that these conditions will be good for spread if there are still green leaves on the plants even after the grain is at maturity. Stalk condition in many corn fields I’ve been in is quite poor. This will be yet another fall where I believe it will pay to get the crop out as early as possible. I’ve continued to receive a few calls on soybean issues, mostly related to disease issues like SDS and white mold.”

Heavy tar spot pressure observed in R5.5 corn in Madison County. Photo credit: Meaghan Anderson, ISU. 

East Central, Southeast, and South-Central Iowa

Rebecca Vittetoe (Region 8): “It had been about a month since most areas in EC Iowa received much for rainfall, and the drought monitor reflects how dry we are with most of EC Iowa being in a severe (D2) to extreme (D3) drought). In the last couple days, some much welcome rain fell across EC Iowa, with totals ranging from about 0.1 to over 1 inch in areas. While for most crop fields this rain came too late, it will benefit forages and will be a start to replenishing our soil moisture for next year. The dry conditions and heat really pushed crops along and pushed some to maturity prematurely. Silage harvest began the second half of August and is mostly wrapped up. I’ve started to see a few more combines rolling in corn fields over the last week. Yield and moisture reports have been variable. Do pay attention to stalk quality in corn fields this fall as I’ve seen some poor stalk quality in fields. I’ve had more questions on soybeans the last couple of weeks, either due to the dry conditions or to diseases like sudden death syndrome, soybean vein necrosis, and white moldas well as questions the end of August on late summer seeding of forages with the dry conditions (not recommended) or about seeding cover crops with the dry conditions here this fall.”  

Pastures and forages across EC Iowa look tough with the dry conditions. Photo credit: Rebecca Vittetoe, ISU. 

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


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...