How farmers harvest corn and soybeans

In Iowa, harvesting corn and soybeans isn’t just a fall tradition—it’s the culmination of months of planning, decision-making, and heart poured into every acre.

At a basic level, harvest includes:

• Getting equipment ready
• Combining corn and soybeans
• Storing and/or delivering grain
• Preparing the land for next year’s crop and conservation planning
• Financial planning and post-harvest crop marketing

But as with any process, there’s more that happens behind the scenes we don’t always see from the road.

What happens between planting and harvest? 

As crops grow over the summer, farmers scout their fields for emerging issues. For example, 2025 marked the sixth wettest summer in 153 years. This rainfall, in combination with extreme heat, created a breeding ground for southern rust—a crop disease that significantly impacts corn yields.

Insects that feed on crop leaves or roots can be a detriment to healthy crop growth, too. And farmers may notice other issues, such as discoloration on corn leaves due to lack of nutrients.

If these problems exist, farmers will work with their agronomists to find the best solution to protect and promote healthy crops.  

Summer is also primetime for machinery repairs and grain deliveries. Grain bins on the farm need to be emptied and cleaned out by late summer to make room for the incoming corn and soybeans growing in the field. Even though corn and soybeans are harvested in the fall, many farmers store their grain and pre-sell their crops for spring or early summer if prices look more favorable.

When is harvest season for corn and soybeans? 

Generally, corn and soybean harvest in Iowa begins as early as mid-September and goes as late as the end of November. For each farmer, how long harvest takes depends on how many acres they farm, how many people they have to help out, the size of their equipment and how many combines, tractors and semis they have running. On our mid-sized farm, our “harvest” crew includes my husband, his dad and another family member, when needed. If conditions are perfect, they can combine roughly nine acres of soybeans and seven acres of corn (an acre is about the size of a football field if you chopped the endzones off) in one hour. A farm running larger and more equipment can get more ground covered in less time.

How is corn combined? How are soybeans combined?

From the outside of a combine, you can see the crop enter the machine, grain fill the tank at the top and leaves and stalks exit out the back. But there are sophisticated mechanisms inside a combine that separate the parts of a corn and soybean plant and direct each part where it needs to go. The Illinois Farm Bureau has created an easy-to-read graphic (below) showing these intricacies.

A single combine can harvest both corn and soybeans, but different attachments put on the front of the machine determine what is being harvested. A corn head has long pointy cone-shaped fingers on the front called snouts. In between each snout, a stalk will be gathered and drawn into the front auger.  A soybean head cuts off plants at the ground, and a large rotating reel with skinny tines rakes the plant into the machine.

Many farmers use real-time technology in their combine cabs to track yield and moisture levels as they harvest. This data helps them make quick decisions about crop storage and highlights areas in the field that may need extra attention next season.

What happens to corn and soybeans once they are harvested? 

Corn and soybeans are used as a nutritional feed source for livestock, which later enter our food supply as a high-quality, nutrient-dense protein our bodies use to maintain their health. These grains are used in other foods, too, like the bowl of corn flakes you start your morning with. But they have so many other uses aside from food.

When you commute to work, your car is likely being fueled by a blend of gas and corn-based ethanol (your tires may be made out of soybeans as well). Materials that hold your house together like plywood and insulation are manufactured using soybeans. From toothpaste to medicine, there are thousands of everyday items made with the soybeans and corn grown and harvested in Iowa that are used not only in our great state but across the globe.

What happens after harvest?

After harvest, farmers might work stalks into the ground, chop them for livestock bedding or let cattle graze them in the field. Forty percent of farmers leave stalks completely undisturbed, a practice called no-till, and 23 percent of farmers use reduced tillage methods. These practices help prevent soil loss to nearby streams.

Farmers also seed cover crops in the fall. These hardy plants hold nutrients and soil in place over the winter, and research shows they can reduce nitrate loss by 30 percent. According to the Iowa Nutrient Research & Education Council, farmers planted nearly 4 million acres of cover crops in 2023. 

Additionally, farmers may take soil samples after harvest, which are sent to a lab for analysis. The results show how much of a specific nutrient is needed, in what amount and in what location across their field. By using this data, farmers ensure the right balance of nutrients for crops and reduce chances of nutrient loss.

Have more questions? Ask! 

Farmers would rather you ask them questions about agriculture than consult Google or AI summaries, which don’t have boots-on-the-ground experience.

If you don’t know a farmer personally, follow your local county Farm Bureau Facebook page to see what farmers in your area are up to and comment any questions you may have. Because when it comes to agriculture, the best source is the people living it every day—Iowa’s farmers.

Learn more about author Caitlyn Lamm here.