Corn

August 25, 2022

Corn is the largest and most widely cultivated feed grain in the U.S., with 90 million acres planted making up 95% of the total feed grain production. In fact, corn covers about 30% of the total crop acres in the U.S.

In addition to providing nutrition for animals, there is nothing in your day that this far-ranging crop does not touch, from the plastic in your bottle of shampoo to the flavor of your breakfast cereal.

How does corn grow?

Contents

ear of corn on stalk

Intro To Corn

The corn fields in the U.S. are the size of Colorado and New York combined. Corn is a pillar crop of energy production, animal production, and farmers’ livelihoods across the country.

Where Is Corn Grown?

Commercial corn production occurs all across the U.S., but the bulk occurs in what’s known as the Corn Belt, which primarily covers:

  • Illinois
  • Iowa
  • Indiana
  • Eastern portions of South Dakota and Nebraska
  • Southern Minnesota

Corn is also grown as a cash crop in Western Kentucky and Ohio as well as the northern two-thirds of Missouri. The two top producers — Iowa and Illinois — grow one-third of the corn in the U.S.

corn field rows

Major Corn Varieties

Two main types of corn dominate U.S. commercial production: dent and seed. Three additional varieties round out corn production for human consumption, and two others — flour and waxy — are grown primarily in the Andes and China, respectively.

1. Dent Corn

This is the field corn that is everywhere, waving across wide fields in the middle of the country. The crown of each corn features a namesake dent. This is a low-sugar, high-starch corn that is most often used as animal feed. However, because the starch is soft, dent corn is frequently used in consumer products such as:

  • Tortilla chips
  • Masa
  • Bourbon

Additionally, 40% of dent corn is used to produce ethanol.

2. Seed Corn

Seed corn is grown specifically to produce the seeds for other corn crops. It is considered a specialty crop because it is more labor-intensive to grow and has more specific soil needs.

Genetics vary according to the end crop. Seed corn undergoes detasseling, or removing the pollen-producing top of the plant, in order to keep it from self-pollinating.

3. Flint Corn

Flint corn is also referred to as Indian corn or calico corn. It is not eaten fresh but is dried, ground, and used in:

  • Cornmeal and flour
  • Hominy
  • Polenta
  • Grits
  • Popcorn

The U.S. does not plant much flint corn. South American countries are major exporters of this, but some small producers grow this as a specialty crop for chefs and consumers.

4. Sweet Corn

Accounting for only 1% of corn grown in the U.S. but the type most familiar to home gardeners, sweet corn is the delicious, creamy ear that comes to the dinner table. The high sugar content is what makes it so prized.

Sweet corn is usually labeled white, yellow, or other colored varieties. Super-sweet corn with enhanced sugar content is also available.

5. Heirloom Corn

Heirloom corn is not mass-produced in the U.S., but it’s a variety worth noting. This type of corn is grown by farmers looking to preserve and restore corn that has nearly disappeared.

How Does Corn Grow?

A good crop starts with good soil that is warmed to at least 50 degrees for proper germination of the seed. After that, much of the planting schedule depends on the variety of corn planted, plus local weather conditions. For most, planting season starts in late April or early May for the highest yields.

Corn is sown in rows of relatively shallow depths of about one to one-and-a-half inches.

Corn Growing Stages

The stages of growth are as follows.

1. Germination: This occurs as the corn seed begins to metabolize and interact with moisture. With good weather and proper fertilizer, a “radical” emerges anywhere from two to five days after planting (it can take up to 14 days if conditions are not ideal).

2. Vegetative growth stage: The first three parts of this stage are emergence, first full leaf, and second full leaf of the corn. The corn seedling begins to more closely resemble the final product. At the end of this stage, the seed is no longer a source of nutrition for the plant — photosynthesis takes over.

3. Tillers: These branches emerge out of the lower nodes of the corn.

4. Ears and tassels: The ears are female and the tassels are the male parts of the corn. During this stage, stress can reduce the yield of the corn. It’s critical to make sure it has proper levels of water and nutrients.

5. End leaf production: This is the last of the new growth of leaves. The corn picking height may have been achieved, but the corn itself is still growing.

After these stages, sexual reproduction, silk emergence, and kernal development takes over. Starch accumulates and moisture declines.

It’s time to consider when to harvest the corn.

corn field

Corn Picking Height

Generally speaking, picking corn has less to do with the corn height and is more concerned with the variety of corn and its intended use.

1. Dent corn: Harvest occurs when this corn is fully mature. It is not meant to be eaten fresh, so harvest occurs when the kernels are dry.

In commercial production, moisture is probably the biggest factor determining when corn should be harvested. This corn must be stored dry, so farmers aim to harvest corn between 15% and 25% moisture content.

Most commercial harvests are completed by November, but some extend to December.

2. Seed corn: Seed corn is generally harvested between 30% and 35% moisture content in order to protect the kernels. It undergoes further drying in storage. Seed corn harvest in the U.S. is usually completed in September and October.

3. Sweet corn: Picking it in the “milk stage” before it’s fully mature keeps the sugar intact and prevents sugars from turning into starch.

4. Flint corn: This should be picked when the husk is papery and dry.

5. Heirloom: Heirloom varieties will all have different picking times that can change depending on the climate.

Corn Soil Needs

In general, corn prefers an almost neutral soil pH of 6.0 to 6.8. The soil should be light and well-drained unless you are planting late in the season.

Phosphorus, nitrogen, and potassium (commonly referred to as PNK) are all necessary for corn cultivation. The amount varies depending on the needs of the soil, so testing is critical before and during production.

Corn Water Needs

A healthy, high-yield crop requires 22 to 30 inches of water per year, but young corn cannot stand in water for longer than three or four days. Drainage tile is used extensively in the Midwest to remove excess water from soils to keep them from being over saturated.

Many areas of the U.S. receive ample rainfall for corn production, but in areas where that’s not the case, crop irrigation is critical.

Corn Market Size And Price

In 2021, commercial farmers produced just over 15 billion bushels of corn. This number is up 7% from the previous year and is the second highest yield on record. These yields are projected to rise due to both technological improvement and in changes to production practices. This includes things such as:

  • More varied seeds
  • Better understanding of fertilizers and pest management
  • Better machinery
  • Crop rotation
  • Irrigation
  • Reduced tilling

The market for all types of corn is continuing to grow, and the price per bushel is increasing, too. In the earliest years of the 2020s, corn prices reached record highs, with no sign of slowing.

many cobs of dried corn

Corn Uses And End Markets

One of the reasons corn is so widely and successfully cultivated is its broad range of uses and applications as both an end product and a raw material.

The United States exports approximately 36% of its total corn production to other countries. The food industrial products are a part of nearly every product that people in the U.S. (and across the globe) consume, including:

  • Fuel ethanol (accounting for nearly half the U.S. corn crop)
  • Animal feed (which becomes more important as the global population and attendant demand for animal protein grows)
  • Starch
  • Sweeteners
  • Corn oil
  • Beverage alcohol
  • Industrial alcohol
  • Seed for future crops (which is, again, grown differently from standard field corn)

With legitimate concerns about monocropping and its effects on biodiversity, some farmers are considering growing corn using organic methods.

There are some important considerations when making this switch, including:

  • Higher market prices for organic products (which equal higher profits even on smaller yields)
  • Federal support for making the move to organic farming
  • Hurdles like different equipment costs, yield loss, and the three-year transition period
  • The ongoing challenges of organic farming (including but not limited to pest control)

Ultimately, individual farmers will decide whether or not organics work for them. Currently, organic corn remains a niche market allowing farmers to differentiate their product, but conversation and developments around organic production continue to increase globally.

Final Thoughts

It’s not an understatement to say that corn is the backbone of U.S. agriculture. Contributing to food, feed, and fuel production around the world, corn is omnipresent in the products we interact with on a daily basis—not to mention much of the American landscape.

Take a look at our current offerings page to see real farms in active corn production.

Megan Blankenship grew up in the rural Arkansas Ozarks in a family of small farmers. Before joining AcreTrader, she worked in advertising and communications for top-tier agriculture clients. She loves writing about land, farming, and the people who care about them.

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