What Do They Mean? Corn Vocabulary

As with many industries, there’s lots of jargon and learned vocabulary in agriculture. We’ve spent some time unpacking cattle-related vocabulary in previous blog posts, which you can find here, here, and here. However, recently I had an interaction where I was using some corn-related jargon and had to back up and explain what I meant. That made me realize how many pieces of the corn industry have vocab words many people don’t know! Here’s an outline of some of the big terms and what they mean.


Maize: Maize just means corn! For our international friends, maize may actually be the preferred term.

Husk: The husk of a corn plant is the leaves that grow around and protect the ear. When we buy fresh sweet corn, the husks are green and pliable. When farmers harvest their field corn in the fall, the husks are brown, dry, and brittle.

Husk can also be a verb and refer to when someone removes the husk from corn before they use it. People may also say they “shuck” corn when they do this.

Stalk: The stalk is the main stem of the plant. Some corn plants will grow up to 8 feet tall and most of that height is from the stalk.

Tassel: The tassel is the male flower portion of the corn plant. The corn plant is interesting because it has both male and female flower parts, but they are not part of the same flower. The tassel grows out of the top of the plant, and the female part of the flower (the ear) grows nestled between the leaves and stalk of the plant.


Detasseling: Many people have had jobs detasseling corn. As it sounds, it means removing the tassel from the plant! This is not done on every farm, however. This is only done when farmers are growing corn that will be used for seed to plant new fields. Farmers sometimes cross-breed two different types of corn and want to make sure the cross happens correctly. They contract with seed companies and those companies provide the genetics for growing this seed corn.

When farmers or researchers are crossbreeding varieties like this, they will plant a small amount of “male rows” that will keep their tassels, and a larger amount of “female rows” that will have their tassels removed. This ensures the ears of the female rows are only being pollinated by the tassels on the male rows. This is how we get hybrid plants!

Conservation till: Tillage has historically been used as a way to warm up the soil, create a nice seedbed for seed-to-soil contact, reduce soil compaction, and control weeds. However, we now know that tillage also increases erosion and negatively impacts the natural soil structure. Conservation tillage is a relatively new idea for how to get the best of both worlds. Maybe a farmer will till only where they plant their seed or will use a type of tillage that doesn’t disturb as much of the soil as conventional methods. There are lots of conservation tillage options.

No-till: No-till is another method of field management, but in this method, they don’t till at all! Farmers who don’t till may use a grain drill fitted on their planter to plant their seeds and may be more dependent on chemical weed control. However, they will gain benefits of reduced erosion (benefiting water quality) and see an improvement in soil health.


Trash: If you hear a farmer talk about trash on their field, you may think they have a littering problem. But likely, they are just talking about leftover plant residue from previous years. In fact, planters can have angled, toothed discs that help clear the soil of this trash to ensure the seed gets good soil contact. Though these are formally called row cleaners, these discs are sometimes called trash wheels or trash whippers.

Silage: Silage is an interesting corn term. Corn silage is harvested differently than the grain you may see at a grain cooperative. Silage is the entire corn plant that is harvested while green in the summer. The whole plant is chopped up and held in an airtight container (like a silo, silage bag, or silage pit) to ferment. It is then stored and used as cattle feed throughout the year. It smells amazing, and cattle love it because the fermentation makes it slightly sweet.

Silo: A silo is a tall, metal, cement, or clay structure originally used to ferment silage. Though silos aren’t as popular as they used to be (many farmers today use silage pits or silage bags), they are a popular addition to farm scenes in storybooks.

Side-dress: This term doesn’t mean anything about clothes. It has to do with fertilizing! It has become clear that for both financial and environmental reasons, it is important to put fertilizer where it will be safe from the elements and actually reach the crop when the crop needs it.

This is where side-dressing comes in. This is the term used for the placement of fertilizer that is two inches beside and two inches below the seed. Farmers may side-dress nitrogen shortly after (or even during) planting, to make sure that that nitrogen is there for the plant as soon as those roots start to grow.

Anhydrous: Nitrogen is the most limiting nutrient for corn. Anhydrous ammonia is the most affordable form of this nutrient for farmers to use. It comes in large tanks that you may see at cooperatives or in fields. You may hear farmers talk about seeing the anhydrous tanks out or getting anhydrous on their fields. They just mean nitrogen fertilizer!


Sprayer: A sprayer is a large piece of equipment that helps farmers spray their fields for weeds or pests. They have tall, skinny wheels, and a very high clearance, so they can be driven through corn fields even when the crop is fully grown. The boom on the sprayer can be raised and lowered, the nozzles can be changed for different chemical applications, and applications can even be altered while the machine is turning!

VRT or Variable Rate Technology: VRT is a really cool technology that is part of the precision agriculture movement. It essentially means that nutrients, pesticides, or other applications are only applied at the exact place where they are needed. Variable Rate Technology helps with this by reading maps and following GPS signals to understand things such as one spot in a field needing less nitrogen than another, and will adjust the rate applied to the field accordingly.

Combine: A combine is a machine that harvests the corn crop. To harvest corn, a combine uses a corn header, which looks like it has big teeth or witch-y fingers. The row of corn is guided in between the fingers, the plant is cut off and guided inside the machine, where the ear is picked, husked, and the kernels are shelled, or knocked loose from the cob. Then, the kernels are stored in the hopper, and the rest of the plant material is put back onto the field.


Grain bin: A grain bin is a big, round, metal, corrugated structure that houses grain. Though not every farmer has a grain bin, they can give a farmer flexibility of when they can sell their crop. Without a grain bin or similar grain storage facility, a farmer would have to sell their grain as soon as they harvested it or pay to have someone else store it for them.


Stover: This is what we call all of the corn plant material that is left on the field after harvest. This is primarily the dried stalk and leaves of the plant. The plant material can protect the soil from the elements and provides extra organic material to the soil (which translates into healthier soil with more nutrients).

Dock: If a farmer goes to sell their corn at a cooperative and it is damaged, contains inert material (like rocks or weed seed), or is too wet, their price may be docked. Naturally, farmers don’t want that, so they work to harvest and sell high-quality corn.


Are there any other terms you’ve been wondering about? Let us know, and you might see it in a future blog!


Why do they do that? Anhydrous


Early in the spring and late in the fall it is common to see tractors pulling large white tanks across bare farm fields. So, what are these strange white tanks? What’s in them and why is it applied to fields?

They are anhydrous tanks filled with anhydrous ammonia (NH3) – one of the most efficient and widely used sources of nitrogen fertilizer for agricultural crops like as corn and wheat.

Nitrogen is one of the 17 essential elements required for plant growth. Nitrogen is most commonly found in the atmosphere making up approximately 78% of the air that we breathe. But in the air it is in the form of N2 which is not available to plants to use. Nitrogen is part of chlorophyll which makes plants green and allows them to use sunlight to produce sugars (food) from oxygen and carbon dioxide through photosynthesis. Nitrogen supports strong vegetative plant growth, which is vital for good fruit and seed development.

Plants use nitrogen by absorbing either nitrate (NO3) or ammonium (NH4) ions through their roots. Soybeans and other legume plants can convert atmospheric nitrogen into a usable form because of nitrogen fixing bacteria on their root nodules. Other plants, like corn, need to have an ample supply of available nitrogen in the soil. Farmers can add nitrogen to fields in the form of livestock manure, granular urea, liquid nitrogen (UAN solution), and anhydrous ammonia.


When making environmentally and economically sustainable decisions about fertilizers, farmers consider the 4Rs best management practices. This helps them select the right fertilizer source and apply it at the right rate, right time, and right placement in the soil.

Anhydrous ammonia is often a preferred nitrogen source for many reasons. It is more concentrated than other forms of nitrogen, containing 82% nitrogen. It is readily available, because it is used in the manufacturing process of other nitrogen fertilizers. It can be applied long before the crop is planted. It is usually the most economical option as well.

Farmers store and transport anhydrous ammonia in liquid form in pressurized tanks. Using an anhydrous applicator pulled by a tractor, the high-pressure liquid converts to a liquid-gas mixture as the pressure drops while traveling from the tank to the knife outlet on the applicator. The knife slices the soil and injects the fertilizer 6 to 8 inches into the soil.

Once in the ground, the ammonia (NH3) ions react with moisture in the soil and convert to ammonium (NH4). Ammonium ions are very stable in the soil. They carry a positive charge and are bonded to negatively charged soil particles like clay and organic matter. These ammonium ions can be taken in by plants and used directly in proteins. Over time, the ammonium converts to nitrate (NO3) which is the form of nitrogen most used by plants for growth and development. Nitrate does not bond to soil like ammonium does and could leach out of the soil and into waterways. Nitrogen fertilizer stabilizers are often added to anhydrous ammonia before application to slow the conversion of ammonium to nitrate, thus helping to reduce nitrogen loss from leaching.


Because of the stability of anhydrous ammonia (and converting to ammonium) it can be applied in the fall with less potential to leach, volatilize, or to be lost in water runoff than other nitrogen fertilizers. Cooler soil temperatures help keep the ammonium ion stable and so farmers try to apply it in the fall after the soil temperature drops below 50°F. If applied in the spring, it is best to apply it at least 3-5 days before planting to avoid damaging seeds and emerging roots.

Good nitrogen management is critical for growing healthy plants, good yields, and a profitable farm business. Farmers consider crop nutrient requirements, results of soil tests, soil conditions, weather, cost, time, and equipment available before choosing a fertilizer program that is the best fit for their operation.