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Optimum nitrogen fertilizer rates for corn can vary by more than 100% from field-to-field and year-to-year. This variability is a product of near limitless interactions among crop genetics, management, and environment factors (weather & soil type). Among them, the amount of soil inorganic nitrogen in the soil is one of the most important (Baum et al., 2024).

As we look ahead to spring, many wonder what conditions to anticipate and how this spring may compare to last. This article provides a brief climate outlook and information about current soil moisture conditions across the state. 

Climate outlook

To maintain your private pesticide applicator certification, you must either pass an exam every three years or attend an approved Private Continuing Instruction Course (P-CIC) between December 1 and April 15 each year your certification card covers.

In 2024, the effect of commercial fungicides on foliar diseases of corn were evaluated at six Iowa State University Research and Demonstrations Farms: the Northwest Research and Demonstration Farm (NWRF, Sutherland), Northern Research and Demonstration Farm (NRF, Kanawha), Northeast Research and Demonstration Farm (NERF, Nashua), Central Iowa Research and Demonstration Farms, (AEA, Boone), Armstrong Memorial Research and Demonstration Farm (AMRF, Lewis)

In 2024, commercial foliar fungicides were evaluated across seven Iowa State University research and demonstration farms to determine their effect on disease control and yield response on soybeans.

A common theme for most of us during the winter months is to make decisions for which pieces of equipment to upgrade and which to do maintenance on before heading into the next growing season. 

When it comes to your planter, whether you are considering purchasing a new planter or making upgrades to your current planter, take some time to consider what technology you might want to invest in to improve your planter efficiencies this next growing season.

Key Points

This fall, the Iowa State University Extension and Outreach Crops Team extended an open call for sponsorship to support our four most popular programs: Integrated Crop Management Conference, Crop Advantage Series, CropsTV, and Planter University. The Crops Team thanks and recognizes our Champion Sponsor this year—Bayer—for their generous support of these programs and also extends our gratitude to all sponsors for their support.

Iowa State University Extension and Outreach Field Agronomists have completed their fall survey of subsoil moisture in northwest Iowa. Subsoil moisture sampling in Iowa dates back to February 1954 when ten sites were chosen for soil moisture sampling. In 1959, the sampling increased to 22 locations, and in 1971, 61 locations were sampled. Today, 18 locations are sampled in northwest Iowa.

After harvest is completed and equipment is cleaned and winterized, there’s an activity that can be done in upcoming weeks that could pay large dividends relating to future soybean yields. That task is collecting soil samples to assess the situation with the soybean cyst nematode (SCN) in fields.

The crops are coming out and it’s ALMOST time for farmers to start making fall nitrogen applications. Remember that soil temperatures should be below 50°F at a depth of 4 inches and continuing to drop before making fall nitrogen applications —ideally, the cooler, the better. It's important for farmers to check the soil temperatures in their specific fields, as many factors can influence them.

Iowa State University recently updated its list of soybean varieties with resistance to the soybean cyst nematode (SCN) for Iowa. The list includes 200 varieties with the less common Peking SCN resistance. These varieties can be especially effective in managing SCN producing and higher yields in fields where SCN has developed high levels of reproduction on varieties with PI 88788 resistance.

In the past few weeks, I've received several questions from farmers about whether it’s too late or too warm to harvest alfalfa. The general rule of thumb is to allow 5 to 6 weeks (900 Growing Degree Days, or GDD) between the final harvest and a killing frost, or less than 2 weeks (360 GDD) before the killing frost. Alternatively, harvesting after a killing frost is possible, but it should be done soon afterward to limit nutrient leaching.

As we move through what has been a very rapid harvest season, there are a few things to keep in mind for preparing this crop for what likely will be a long storage period.

This article is Part 5 in a series of five blogs on how best to allocate fertilizer dollars. 

One of the most frequent questions Extension professionals receive regarding soil fertility is do I need to add micronutrients to my soil fertility program? The classic answer “it depends” is really true in this case, but research done at Iowa State University and other universities across the upper Midwest shows there is no consistent yield benefit to applying micronutrients. 

This article is Part 4 in a series of 5 ICM blogs on how to best allocate fertilizer dollars with tight margins.

While dry (dry, and drier) soybeans are common every year, this year we’re seeing the more unique situation of harvesting very dry corn grain. In some cases, loads of corn grain are headed to market at sub 12% moisture. With the current dry conditions and no rainfall in the forecast, harvest challenges are going to continue.