Why Do They Do That? Rotating Crops

It’s still winter outside, which means farmers are carefully planning how they plan to manage their crops starting in the spring. One thing that farmers carefully plan is what crops they want to plant in what fields.

Though you may not notice by driving by farm fields every year, most farmers plant different crops on their fields year after year. For example, one specific field in 2016 might have been planted in corn and another field might have been planted in soybeans. Then in 2017, the first field may have been planted in soybeans, and the second field may have been planted in corn. This is called a crop rotation. But why do they do that?


There are multiple reasons and multiple ways to rotate crops. The first, and likely the most prevalent reason, is nutrient uptake in plants. Compared to other crops, corn needs lots of nutrients, especially nitrogen. This makes soybeans a good crop to alternate with corn, because soybeans have nodules on their roots that host bacteria that fix atmospheric nitrogen. Thus, soybeans require less nitrogen to be applied to the field and they deposit more nitrogen into the soil. Other legume crops, like alfalfa, offer similar benefits.

Another reason farmers rotate crops is to break fungus, disease, or insect life cycles. By changing up the type of crop grown in a specific location, you can disturb certain pests that rely on that environment. However, if this is a large concern, the field would likely require more than one year of an alternate crop. For example, soybeans are often affected by nematodes. Nematodes won’t feed on corn like they do with soybeans. By rotating corn and soybean fields, farmers can minimize the nematode population that might affect their soybean yield.

Planting various crops year after year can also benefit soil tilth. Different crops have different root structures, which can help aerate the soil in different ways, as well as provide different amounts of organic material to the soil.

In Iowa, many farmers do a corn-soybean crop rotation, meaning one year they will plant corn on the field, and the next year they will plant soybeans before returning to corn the following year. They are able to do this because Iowa has relatively healthy soils, and both of these crops offer farmers here the most financial gain at the end of the season. However, lots of research is being done on extended crop rotations, which add in other components, like small grains (like oats) and forages (like alfalfa).

According to Soil Fertility and Fertilizers by Havlin, Beaton, Tisdale, and Nelson, “Numerous long-term experiments have demonstrated that, in general, rotations increase long-term crop and soil productivity compared with continuous cropping.” Extended crop rotations could also play a role in mitigating nitrate losses.

However, these extended crop rotations are not always an easy sell. Because the markets in Iowa tend to favor corn and soybeans, small grains and forages might not be valuable if the farmer doesn’t also raise livestock. That said, even if extended crop rotations aren’t the best option for a specific farmer, two-year crop rotations, conservation tillage systems, and responsible nutrient management are all tools that can help to meet similar objectives.

soybean square

In summary, crop rotations are good for many things, but mostly help to keep the soil healthy. Iowa’s main crops are corn and soybeans, and when alternated, they can help each other grow the best they can.


How Does it Work: Grain Elevators

Farmers plant corn in their field in late April and May and in the fall corn is harvested by a grain combine. Once the corn is harvested (usually in September, October, or November) it is dried and stored on a farm or in a grain elevator and from there is shipped to mills and refineries. So, how does a grain elevator work?

Combines harvest grain out of the field and transfer it to a grain cart or directly into a truck that can carry the crop to the grain elevator. Grain elevators are located near railways or waterways to accommodate shipping the grain out after being processed. Elevators are generally in small rural areas which is less distance for the farmer to haul the grain. It is easy to recognize the grain elevator. 1It is sometimes the tallest building in town, between 70 to 120 feet tall!

The truck carrying the grain pulls into the local grain elevator and then stops on the scale at the elevator to be weighed. The operator takes a sample of the grain to test for the weight, moisture content and to check for any foreign materials present. Foreign materials could consist of chewed up corn, stalks, weeds or trash. To store grain, the moisture content needs to be around 15% or the grain might mold at higher percentages or be too dry at lower percentages. If the grain is too wet farmers have to pay to have it dried at the elevator. Either one of these scenarios will lower the cost per bushel.


The grain is then dumped from the truck to a work floor of the elevator. The work floor is an open, slatted floor where the grain dumps into pit and will then travel on a continuous belt that has buckets attached to scoop up the grain and then deposits it into silos. This bucket system elevates the grain taking it from the floor to the top of the silo (thus the whole facility is called a grain elevator). The empty truck will drive back to the scale to weigh the truck again. This will tell the elevator operator how much corn was unloaded.

The farmer will be given a receipt called a weight or scale ticket. This ticket will tell the number of bushels calculated as being brought to the elevator. It is important for the  farmer to know the weight of the grain that was dumped. Corn is sold by the bushel and the standard weight of a bushel is 56 pounds. It is the measurement for weight when buying or selling crops. The ticket will be a record of delivery for the farmer. The scale ticket will show the date, quantity, kind of grain and quality of the grain being delivered. It will also tell if the grain is to be sold or stored.

Grain elevators were created to hold crops being purchased or available for resale, and 7to help with the problem of storing grain. The essential function of storage is to protect the grain from the elements and allow for it to be stored and tracked for quality and temperature. The inside building houses a vertical storage with bins that allows for easy transport of the grain. Proper storage is of utmost importance. If the crop is left in the field it can have reduced return on investment due to insects, mold and birds or rodents. Crops must be clean. The moisture content is a major factor for storing safely. High moisture can lead to mold and fungus. As grains reach maturity the moisture content diminishes.

Storage of grain will allow flexibility to the farmer to use marketing and possibly receive season price increases. There is a cost incurred for storing grains, so the farmer must decide based on storage capacity and expected returns after storage. If selling the crop later for a price that exceeds the current selling price is the better decision, the farmer will choose to store the grain. Proper use of storage will potentially increase the income cost for the grain. However, the farmer will need to take into consideration storage costs, which can include facility cost, interest on grain inventory, extra drying of the grain, shrinkage of the grain and handling fees.

Farmers have choices on how to sell their grain. They can choose to do a forward contract and sell to a grain dealer at any time. A forward contract allows the farmer to know exact price, exact quantity and date of delivery. The downside is if prices go up, the farmer is already locked into the forward contract. If the farmer does choose to store the grain and sell later, he can sell to ethanol plants, bio-diesel plants or to livestock feed producers. The farmer will negotiate prices and will choose to sell throughout the year. Keeping in mind the cost to store and the importance of keeping the grain suitable for purchase.

When the grain is sold it may leave the   elevator it may be into a rail car, truck or barge. Gravity is usually used to load grains from bins to the loading station. The process of loading and a reversal of the process for unloading. The empty truck pulls onto the scales and is weighed. The truck will pull under the spout and the grain will load back into the truck. Both the trucker and the elevator operator watch the gauges to know when to shut off the grain. The truck will pull back onto the scales to get an accurate weight and then will deliver the load to the destination.

There is so much more to agriculture. The process of getting the grain to and from the elevator is full of important steps, none of which can be omitted. I realize that the job of farming has so many aspects that go unnoticed, but are vital to the result which is food, fuel and fiber for the hungry world. I send a huge thank you to the Farmers!

– Sheri


Keeping Livestock Comfortable In Frigid Conditions

It is no surprise that Iowa winters are frigid cold. The freezing temperatures, snow, and sometimes icy conditions can wreak havoc on livestock producers. How do farmers care for their livestock in the frigid temperatures?

1.       Keep Enough Feed and Water Available

Increasing the amount of feed available to livestock can help them prepare for the cold. They are consuming more nutrients in the feed and that means they are consuming more energy. Providing good quality forages like alfalfa and grass hay goes further than just providing more grain

water heater

Image borrowed from: factsaboutbeef.com

Livestock must also have access to water at all times. To keep water troughs from freezing, farmers can use a variety of tricks. Electric tank heaters provide a steady supply of heat to keep the water above freezing. The heater can be submerged, like the photo,  so animals won’t bother them as much. The warmer water also encourages consumption. Water temperature of 37° Fahrenheit or warmer is ideal for livestock. If heaters are not an option, producers should offer fresh, unfrozen water several times a day to make sure that livestock can meet their daily water requirements (three gallons for sheep and fourteen gallons for cattle). 


2. Shield Livestock from the Elements

Image borrowed from: http://Flicker

Farmers provide windbreaks to protect the livestock from strong winds. The windbreak should be located perpendicular to prevailing winter winds. In Iowa, windbreaks are located on the north and west side of the fence. Wind breaks can be made using different designs. The multi-row windbreak design incorporates three or more rows of trees and shrubs.  Dense conifers are planted in one row. The multi-row windbreak design provides a large plant population, greater protection, and valuable wildlife habitat. There is also a twin-row, high density design that uses closer tree spacing between rows than the multi-row design. You can also use portable wind fences to protect livestock. Wind fences can be made of bale piles (hay or straw, or inedible biomass). Even snow piles pushed up by loaders can dramatically slow wind speed. Whatever type of windbreak farmers provide, it will dramatically reduce wind speed and increase temperatures for the livestock.

3. Have Bedding Available


Image borrowed from: soilassociation.org

Bedding helps livestock stay dry and comfortable in winter conditions. It insulates the livestock from the cold ground. Straw, corn stalks, wood chips are a few types of bedding that livestock producers use. Newborn animals should be provided clean, dry bedding as needed in their pens. The bedding keeps animals relatively clean from mud and protects them from frostbite. Providing bedding for livestock can also improve feed efficiency and overall animal health.

With a few added steps during the cold climates, farmers will have their livestock feeling comfortable in the frigid Iowa winter. 




future ag teacher 2

P.S. My name is Laura, I recently started as the Education Programs Intern for IALF. I am a Sophomore at Iowa State University studying Agriculture and Life Sciences Education. My agricultural background started on our family acreage in South East Iowa raising sheep and chickens. I was highly involved in 4-H and FFA and now continue to be involved in collegiate organizations: Sigma Alpha, AGED Club, CALS Council, and CALS Ambassadors.





Preg Check – Why Do They Do That?

Calves are starting to hit the ground!

beef_cow18.jpgThat is farmer-speak for this time of year (January, February, and March) when many cows on farms and ranches start to give birth to new calves. For the average passerby this can seem like a miracle of life. But for a farmer, it is the end of a closely watched pregnancy and something that is 283 days in the making. In the early stages, many farmers will conduct pregnancy checks on their cows. But why do they do that?

Farmers who raise breeding stock keep a close and watchful eye on their animals. The average gestation period for a cow is 283 days. But it can range from 279 up to 287 days (approximately 2 weeks longer than a human pregnancy). Human mothers will do doctor check-ups regularly throughout their pregnancy to ensure that everything is going smoothly and that the fetus is developing normally. Just like humans, cows will receive some regular check ups from the doctor (veterinarian) too. One of the first check ups is a pregnancy check to determine if the cow is indeed pregnant.

Most cows that are raised together will go into heat or estrus around the same time. A farmer can introduce a bull into the pasture opting for natural insemination or a farmer might choose to artificially inseminate their herd. Through artificial insemination straws of semen, previously collected from preferred bulls based on genetic traits and characteristics, are inserted into the cow through the rectal-vaginal technique. Then 4-10 weeks later the farmer will check to see if the cow is pregnant.

If the cow is pregnant, then the farmer will be able to build their herd. The farmer can monitor the overall herd health and reproductive status keeping detailed records of the pregnancies. Once the calf is born it can be sold for meat or raised to be breeding stock. However, it is just as important to know if the cow is NOT pregnant after natural or artificial insemination. If a cow is open (not pregnant) the farmer can make better management decisions like selling during peak market prices, culling the herd to improve genetics, or trying to inseminate again. If too many cows are open and did not get pregnant, then that could be an indicator of herd nutritional deficiencies or diseases that then need to be addressed.

There are three main methods of conducting these pregnancy checks on cows. An ultrasound technician can recognize a pregnancy in as little as 25 days. This requires a fair amount of preparation and time with each animal. The machines are not cheap. The second method is a blood test. Blood samples from each cow can be drawn and sent into a lab for analysis. The blood needs to be taken at least 30 days after breeding. But the most common method is rectal palpation. This is by far the cheapest and most convenient. Trained veterinarians can identify a pregnancy in as little as six weeks (usually 8-10 weeks). This involves the vet wearing a REALLY long glove (shoulder length) and feeling inside the cow for the calf’s head. The vet can also check for a pulse in the artery supplying blood to the uterus and check the shape of the uterus. A good operation and a well trained technician can pregnancy test up to 60 cows per hour!


Image borrowed from: http://unplugging.us/how-to-check-cow-pregnancy/

The age of the fetus can be estimated, which gives the farmer a better idea of when the cow will give birth. In the cold months of the year, cows may be brought indoors to give birth or otherwise just be more closely monitored. Cows experiencing trouble during birth might be given help and the farmer might pull the calf.

Ultimately, pregnancy testing is of little use as an aid to management unless the information gained is used to make management decisions. This process of pregnancy checking can cause some stress on the cows and can result in a loss of the fetus. Pregnancy loss can be 1-3.5% when palpation or ultrasound are used. So farmers need to take this risk factor into consideration. But most find that the benefits of knowing if the cow is pregnant and making management decisions outweigh the risk. It is important to evaluate the different methods for pregnancy testing and make the best decision for your operation.

If a farmer can sell a non-pregnant female at market in August they could earn prices that are 5-10% higher than prices in October or November. Cows will also lose weight after August due to forage quality decreasing into the fall and winter months. Selling non-pregnant females takes advantage of higher weights. Cattle are sold by weight, so the farmer stands to make more money with heavier animals.  Non-pregnant heifers and cows can provide as much as 20% of the gross income to a cow-calf operation on an annual basis. Making decisions based on information and data allow farmers to manage their operation in the best possible way.


What’s Cookin’: Chocolate Pudding

pudding - small

One of my favorite comfort foods is chocolate pudding.  Not the kind from a box, but the rich and creamy home-made goodness that can only be made by starting from scratch.  If I’m going to indulge in chocolate pudding, I want the good stuff!

While there are many great recipes for chocolate pudding, my favorite is a simple one that even my 8-year-old son can make without help!  Before I share the recipe, here’s the agricultural story behind it’s simple ingredients.

cocoa beansCocoa Powder is made from beans of the cacao tree grown in tropical climates. After harvesting the beans are fermented, dried, and roasted.  The beans are then ground into a paste to separate the cocoa solids from the fat, or cocoa butter. Once the butter is removed the cocoa solids are ground into a fine powder.  The bitter powder can be packaged and sold for as unsweetened coca powder for baking cooking, or mixed with cocoa butter, milk and sugar to create the chocolate bars and chips.

Sugar for home cooking and baking can come from two agricultural crops, sugar cane and sugar beets. Sugar beets are a root crop grown in the upper Midwest.  Sugar cane is a tall perennial grass grown in more tropical environments like Florida, Latin America, and South America.  Although the plants are very different, the process of turning juice from sugar beets and sugar cane into granulated sugar is very similar.  After the juice is extracted, it is purified, and the crystals form as the water is removed through several stages of evaporation.

cornCorn Starch is a fine white powder made from the starchy center, or endosperm, of corn kernels.  In the kitchen, corn starch is used as a thickening agent for sauce, gravy, pudding, and more. Corn starch is comprised of long chains of starch molecules that will unravel and swell when heated in a liquid. This swelling causes the liquid to thicken.

Milk: Long gone are the days that cows are milked by hand. Today’s dairy farms are high-tech and efficient, using mechanical milking parlors and even robots to improve the efficiency of the milking process. Once milk is collected from the cow it is quickly cooled and trucked to a processing plant where it is homogenized and pasteurized before bottling. Once bottled it is sent off to grocery stores or other consumer outlets. The whole process takes less than 48 hours and the milk is never touched by human hands.

vanilla beansVanilla extract is made from the seed pod, or bean, of the flat leaved vanilla orchid.  They are picked unripe, submerged into hot water and then laid out to dry.  Vanilla extract is made by macerating the vanilla beans and mixing them with water and alcohol.

Butter: Fresh whole milk from dairy farms is collected and brought to the creamery. The cream is separated from the milk and rapidly heated to a high temperature. Pasteurization removes any disease-causing bacteria and helps the butter stay fresh longer.  The cream is then churned by shaking or beating it vigorously until it thickens. The remaining liquid, appropriately called buttermilk, is removed. The clumps of butter are then washed and formed into sticks or blocks. Check out this video to see exactly how butter is made.

Chocolate Pudding
½ cups white sugar
3 tablespoons unsweetened cocoa powder
¼ cup corn starch
2¾ cups milk
2 tablespoons butter
1 teaspoons vanilla

Mix the sugar, cocoa powder, corn starch and salt together in a saucepan.

Whisk in the milk and bring to a simmer. Continue to whisk and cook until it is thick. It will not take long after it comes to a boil.

Take it off the burner and mix in the vanilla and butter. Pour into a bowl or serving dishes to cool.



Why do they do that? Floor Slats in Pig Barns

Earlier this fall, I was attending a STEM Festival, where we were presenting our Feed Sacks Pork Lesson. In this activity, students make a snack mix based on the feed rations a pig gets. As part of our set up, we had some photos on the table of modern pig barns, and some real pig feed samples.

At this event, one family came to our booth very curious about what they were seeing. They told me that they had recently moved to Iowa from Alabama, and were not familiar yet with Iowa agriculture.


Upon seeing one of the pictures, the mom asked why the floors looked the way they did. Since many people don’t get the opportunity to see inside the pig barns they notice from the road, I thought this was a great question. Why do they make pig barn floors the way they do?

The flooring in pig barns is slatted, meaning there are long, narrow holes in the floor. This essentially creates a waste disposal system in the barn, making sure that the pigs don’t have to lay around in messes. This is also a much less labor intensive system than having to scoop or remove the waste regularly.

Slatted floors can look different. In the photo above, the floor is cement. Other flooring systems with the same concept could be plastic, or metal coated with rubber. Different producers or different barns might use different styles of flooring depending on cost, the size of their barn, and how safe the flooring will be for their pigs.


Source: http://www.prairieswine.com/about/6551-2/

But what happens to the waste that falls through the flooring? Does it just fall to the ground and stay there? Not quite! Underneath pig barns like these, there are manure pits. Other types of barns have systems where the manure is then moved to a pit outside of the barn instead of directly underneath it. All of these pits are monitored carefully for air quality to make sure there are no accidents that can harm either humans or the pigs. Sometimes the gas produced can be collected and made into biogas, which can generate energy for the farm!

So then what happens with the manure? About twice a year, these pits get pumped out into tanker trucks, and the manure is used as a fertilizer for farm fields. Manure can be tested for nutrients (along with the soil from the fields), and this can help make sure the farmer applies just the right amount of the manure to the field. Manure is most rich in nitrogen, but it is also rich in phosphorus, potassium, and other nutrients essential for plant growth.

In modern manure pits, the waste is stored as a slurry, meaning it’s mostly liquid. This makes it easy to move, and easy to apply to the field. Today, many farmers will inject the manure into the ground instead of applying it to the surface. This is beneficial for multiple reasons. First, this means that the manure is less susceptible to the elements and is less likely to be washed away into a nearby stream. Secondly, by injecting the manure into the soil, it also helps to stabilize the nitrogen in the manure for longer. If the nitrogen was applied to the surface, it would be more susceptible to volatilization, meaning it can transform easily into a chemical form of nitrogen that isn’t available to plants.


Source: https://www.striptillfarmer.com/articles/224-strip-tillers-putting-manure-in-its-place


This whole system of dealing with the messy side of livestock is called manure management. It can also include innovative and interesting ways to keep the smell under control, like using windbreaks and even creating air biofilters out of things like woodchips.

Though manure may be smelly, it plays a big role in Iowa agriculture. We grow crops to feed our livestock, and our livestock produce fertilizer for our crops. It’s an elegant system for an un-elegant topic, don’t you think?

What other agriculture questions have you had? Let us know in the comments, and you might see another “Why do they do that?” blog about your question!


Play dough – Not Just for Playtime

One of my favorite things about the holidays is the extended opportunity to spend time with family. During this holiday break, I decided to do a few hands-on projects with little ones. One of their favorite things to do is to make and play with play dough. I have always let my granddaughters help me make a home-made version of play dough. It’s fun, safe for youngsters, and they can play for quite a long time with cookie cutters and childproof utensils.

This version of play dough came with a little “agriculture” lesson. My granddaughters are Tessa, age 5 and Izzie, age 4. They are very curious about all sorts of things, so I decided while we made the play dough, we could learn not only how it is made, but also where the ingredients come from. Farmers help to make almost all of the ingredients in home-made play dough.

wheat1Flour: Most flour is made from wheat that has been finely ground into a powder. The 1.jpgprocess of making flour from the grain has been around since prehistoric times using a stone club and a stone bowl to grind the grain into a fine powder. Wheat is now grown in just about every state in the United States. The United States in ranks 3rd in the production of wheat and is the #1 wheat exporting country. The top wheat-producing states are Kansas, North Dakota and Montana.

Cream of Tartar: Cream of tartar is a byproduct of wine making. It is made from sediment left in the barrel after grape juice is fermented. This acidic salt acts as a stabilizer. For example, cream of tartar helps meringue retain its shape and texture on top of a pie after it is browned in a hot oven.

soybeans1Vegetable Oil: Most vegetable oils are made from soybeans. Iowa ranks number one in the production of soybeans. Extraction of oil happens when seeds are pressed, then the liquid is sent through a filtration system to sift out remaining seed residue.

OD-BA499_SALTS_OZ_20140108171619Salt: Salt is not an agriculture product. It is a mineral collected by evaporating salt water or mining rock salt.

Food Coloring; artificial and natural food dyes are added to food and beverages to make them more desirable to consumers. Artificial colors are made from petroleum. Natural colors are extracted from fruits, vegetable, and even insects.


  • 1 cup water
  • 1 tablespoon vegetable oil
  • 1/2 cup salt
  • 1 tablespoon cream of tartar
  • Food coloring
  • Saucepan
  • 1 cup flour


  1. Combine water, oil, salt, cream of tartar, and food coloring in a saucepan and heat until warm.
  2. Remove from heat and add flour.
  3. Stir, then knead until smooth. The cream of tartar makes this dough last 6 months or longer, so resist the temptation to omit this ingredient if you don’t have it on hand.
  4. Store this dough in an airtight container or a Ziploc freezer bag.

When it comes time to play, I get out the cookie cutters, plastic utensils, rolling pins,biscuit cutters and anything else they can use with their play dough. We have contests to see who can make the most different things with our “tools”. Eventually some of the green gets mixed with some of the red and the original pretty play dough looks a bit messy, but I can always be assured that we thoroughly enjoy make home-made play dough and playing with it! Take time this week and mix up a batch for the young ones in your home!

– Sheri