Why Do They Do That? –Irrigation

Most of us are familiar with weather and know that it is not consistent every year, and rain doesn’t always come when farmers need it. This is why some large fields resort to using some kind of irrigation system. Even though you may see a large irrigation system while driving down the road, it is helpful to note that most of Iowa’s cropland is not irrigated. According to the USDA, other states outside of the Midwest, such as California, Nebraska, Arkansas, and Idaho, rely more heavily on irrigation systems. This is due to their irregular and infrequent precipitation.

Using this method of irrigation systems to water crops, farmers can control their crops’ water requirements if there is not enough rainfall. Like many things in the agriculture industry, the control of these irrigations systems can be automated and can be done right from the farmer’s phone or tablet. With different technologies, farmers can adjust the water pressure, the amount of water, and more without even being on the field, similar to how you could control your home’s security or temperature with smart technology while being on the road. As advanced as this may seem, these irrigation systems continually advance with the rest of the agriculture industry with solar-powered irrigation systems being implemented more widely in the future.

Photo by Adrianna Calvo on Pexels.com

When deciding what kind of irrigation system to use, farmers have several choices: sprinkler vs. drip and center pivot vs. linear.

sprinkler irrigation system:

This system imitates rainfall by distributing the water above the field surface, allowing it to fall on the crops and soil. All plants on the field should receive the same amount of water, hopefully resulting in similar growth. This system is one of the most popular kinds of irrigation, and you probably have seen them in the fields at one time or another. This system is also similar to what many homeowners use to water their lawns. Like every system, sprinkler irrigation has some advantages and disadvantages. A farmer may decide to go with the sprinkler system because of the reduced cost of overall farm labor and reduced soil erosion. Another farmer may opt out of sprinkler irrigation because of the high initial cost of pipes, motors, and installation, and because of the high water loss due to evaporation.

drip irrigation system:

Compared to a sprinkler system, the drip irrigation system can be more efficient than a sprinkler system because the water is being dripped from a lower point, drop by drop (there is less evaporation water loss). With this kind of system, the soil soaks in the droplets before they can evaporate or be blown away by the wind. The water is applied closer to the roots where it is truly needed. Although drip irrigation may seem like the more beneficial choice, there are some downfalls, including that the water outlets get clogged because they are in direct contact with the ground. These systems also take a lot of training to understand the machine and manage the system.

center-pivot irrigation system:

This type of sprinkler irrigation is just what it sounds like: a mechanical system that moves in a circle with a center point. This machine can also be used to apply fertilizers and pesticides. The chemicals are mixed into the water as the water is sprayed onto the field. This multipurpose system can be used on a variety of crops, including vegetables and fruit trees. The center point is usually a permanent, stationary point where the water is pumped up from an underground well. The long arm of the system stretches across half the field and as it moves in a circle, it waters the entire field. The arm is supported by large wheels that travel across the ground and hold the arm up. If you’ve traveled in a plane over Midwest states like Nebraska, Kansas, and Colorado and looked out the window, you’ve likely noticed the circular fields. Each one of those fields has a center-pivot irrigation system on it.

Photo by Mark Stebnicki on Pexels.com

Linear Irrigation System:

Linear irrigation systems are marketed to irrigate 98% of the field by traveling across the field in a straight line, forward, and reverse working best in square or rectangular fields. This system is another example of a sprinkler system. The water used is either taken from underground or a hose that drags behind the machine’s wheeled cart. In a linear irrigation system, soil compaction is reduced. It is also easier to work in windier conditions, unlike the center-pivot system because they are lower to the ground. Center-pivot systems can work on tall crops like corn. Linear irrigation system are better for shorter crops like alfalfa.

Now that we know what types of irrigation systems are out there, the final question is, why use them? With this kind of technology, crops can be watered in a controlled environment where the lack of rain can be less of a burden on farmers and their yield. Controlling the amount of water applied in a slow and steady manner can lead to less runoff and erosion. Plus, the time that farmers would typically take using more complex kinds of irrigation can now be spent perfecting other areas of the field or farm operation.

Next time you see one of these systems as your driving down the road, now you will have a better idea of what it does! If you’re a farmer, let us know in the comments what works best for you!


Hi! My name is Madison Paine and I am the education programs intern at IALF for the next year. I am currently a junior at Iowa State University studying agriculture communications. I grew up on an acreage outside of Maxwell, IA where my love for agriculture first sparked. I am very excited to be here and can’t wait to see what this next year all entails!

Grazing Cover Crops- Sheepin’ it Real

Seeing livestock eating in a cornfield in the middle of July is enough to cause most farmers at least a slight amount of panic. Animals can do serious damage to a cornfield, and finding them and getting them out of the cornfield and back into their barn or pasture can often involve every neighbor, the sheriff, and random people stopping to block the roads to avoid accidents. Just last week, my family was called to help a neighbor who had some cows out. However, if you find yourself driving the gravel roads near New Providence, Iowa, this summer, you can be assured that the sheep you may see in one Iowa farmer’s cornfield are supposed to be there!

Landon Brown, a fourth-generation farmer, is exploring the world of sustainable agriculture this year. In late April, like many Iowa farmers, he planted hybrid seed corn on his land. However, unlike some other farmers, he planted his corn in 60″ rows, meaning that each row is 60 inches apart. Most farmers in his area planted their corn 30 inches apart. Three weeks later, in mid-May, Brown planted cover crop seed between the cornrows, which was comprised of nine different types of over crops, with the majority being Dwarf Essex Rapeseed. Finally, in mid-June, he went to a sale barn and purchased eight sheep and released them into the corn and cover crop field.

Brown's sheep
Brown’s Katahdin Sheep

Corn is known as a “cash crop,” meaning that farmers grow it to sell and make a profit. It would seem that sheep could do a fair amount of damage to two acres of corn, even in just a few months, resulting in no profit for the farmer. However, these sheep don’t want to eat the corn. They much prefer the luscious cover crop mix of forages that cover the ground between rows of corn. They do munch on the bottom leaves of the corn but leave the majority of the cash crop alone.

Why plant cover crops and go through the trouble of putting up a fence, providing a water source, and buying sheep? The answer is simple: sustainability. It’s been a buzz word for years, and no one can really seem to provide a broad enough, yet specific enough definition. (I took a class this spring that spent weeks trying to nail down a definition). This simple definition came from dictionary.com: “the ability to be sustained, supported, upheld, or confirmed.” Cover crops are one way that farmers are actively working to help make agriculture more sustainable. Cover crops can help reduce soil erosion, they increase the biodiversity of plants, and they provide nutrients for the soil. All of these benefits help protect the land and will preserve it for future farmers. Cereal rye is the most common Iowa cover crop, but you can also find wheat, radishes, turnips, oats, and several other varieties across the state. Find more benefits of cover crops here: 6 Reasons Farmers Use Cover Crops.

lan's crop
A recent picture of an area of grazed cover crops.

As for Brown’s sheep, they are content to graze the cover crops. He purposefully purchased Katahdin sheep, which differ from most sheep in their coat. Katahdin sheep have coats made of hair, so they don’t need to be sheared, like those with wool. They are known for being hardy, low-maintenance animals. Brown said that he hopes to attend a sale this weekend and get eight more sheep, as the cover crop provides enough forage to sustain a 16-head herd.

sheep& crop
Sheep grazing the cover crop

The sheep will continue to eat the cover crop until it’s time to harvest the corn. Harvest will happen in the fall, and after harvest, they will be released back to the field to graze until the first frost, which will kill off the remaining cover crop plants. The sheep will then go to the sale barn.

However, selling the sheep isn’t the end of Brown’s mission to practice sustainable agriculture. He already practices no-till farming, meaning that he doesn’t do any tillage in his fields, which is done to help prevent soil runoff. Next year, he’s planning on planting some fields with relay cropping. Relay cropping means planting one crop into another before harvest. Brown is planning on planting wheat or cereal rye first and then planting soybeans before harvesting the first crop. Relay cropping adds to sustainability efforts by decreasing nitrogen leaching and increasing carbon sequestration. (Relay Cropping). He also hopes to add more sheep and graze more acres of cover crops next year, providing that this year goes well. According to Brown’s Twitter account, he is #AlwaysLearning, and he said that his inspiration for this idea came from a book that his father was reading about farming in the past, and from hearing from Loran Steinlage, another no-till practicing Iowa farmer. (@FLOLOfarms on Twitter).

Brown’s cover crop

Iowa farmers are continually learning and evolving their current farming practices to care for the environment and grow more.


6 Educational At-Home Activities

Hands-on activities are one of the best ways for students to learn. But when they’re home without a full chemistry or biology lab, what activities can they still do? Here are some ideas, each with their own connection to agriculture and our food system.

Surfactant Surprise

Materials needed:

  • Plate or bowl
  • Milk
  • Food coloring or pepper
  • Dish soap
  • Q-tip (optional)


  • Pour milk into bowl or plate, completely covering the bottom.
  • Use either food coloring or pepper to dot the top of the milk. Do not stir or agitate.
  • Place a dot of dish soap either on the end of a Q-tip or your finger.
  • Press dish soap to the milk. The pepper or food coloring will shoot away from the soap!

Agriculture connection:

This activity helps display what soap really does. In agriculture, a crop farmer may use a surfactant while spraying an herbicide. The surfactant is mixed with the herbicide and water to help the herbicide not form water beads, but spread and cover the entire surface of a weed’s leaf. This helps it work more efficiently!

Start Some Seeds

Corn Germinating Roots

Materials needed:

  • Seeds (flower seeds, vegetable seeds, or even dandelion seeds from the backyard will work!)
  • Towel or paper towel
  • Plate, bowl, or tray


  • Dampen a towel and lay it on a plate, bowl, or tray.
  • Scatter seeds on the towel and fold it over the seeds.
  • Keep the towel damp and in a warm place in your house for several days. Watch carefully; the seeds will start to germinate!
  • *This activity can also be done with a plastic bag and wet cotton balls or water beads. All seeds need to germinate is water and warmth!

Agriculture connection:

Farmers plant crop seeds so they can grow food. They plant these seeds in the spring when the soil is warmer so that the seeds will germinate and grow. Seeds wouldn’t germinate outside in the winter!


Packing Peanut Playtime

Materials needed:

  • Biodegradable packing peanuts
  • Water
  • Cup or bowl
  • Plate or tray (optional)


Many packing peanuts currently being used are biodegradable and will melt when wet. If you have packing peanuts, test one by dipping it in water or running it under the faucet before beginning the activity. If it gets sticky and mushy, it is biodegradable.

  • Option 1: Observation
    • What happens when a biodegradable packing peanut is submerged in water? Let students stir and play in the water to see what happens as the packing peanut dissolves.
  • Option 2: Building
    • When the packing peanut becomes only slightly damp, it gets sticky. Allow students to dampen peanuts and stick them together to build barns, towers, houses, or sheds.
    • Prompt students to build a barn with two doors and two windows.
    • Prompt students to build a machine shed large enough for a toy car or tractor.

Agriculture connection:

Biodegradable packing peanuts can be made from corn starch. Iowa is the leading corn-producing state. Biodegradable foams and plastics like these benefit farmers by providing more uses for their products, and also benefit our environment by helping us keep petroleum-based products out of our landfills.

Creative Composting

Materials needed:

  • Food scraps (banana peels, potato peels, coffee grounds, egg shells, etc.)
  • Shredded paper, dry leaves, dryer lint, or other dry biodegradable items
  • A bucket, tub, or open space outside


  • Prepare a container, like a bucket or tub, to hold the compost. Try to allow for ventilation by creating holes in the lid of the container with a nail or drill.
  • Add compostable materials to the bucket. Try to alternate between “wet” (food scraps) and “dry” (paper, dry leaves, etc.) layers. (Do not add meat or dairy products to your compost – they are organic materials, but attract pests and smell!)
  • Stir or shake the container every few days.
  • The materials will begin to break down! And if enough dry material is added, the composter should not even smell. You just made soil!

Agriculture connection:

Soil is one of our greatest resources. Without soil we cannot grow crops or feed livestock. Organic materials like those we put in compost contribute a lot to soil, including nutrients, food for microbes, and increased soil tilth.



Chemistry Kool-Aid

Materials needed:

  • 1-2 cups of soil
  • Funnel
  • Coffee filter
  • Clear pitcher or jar
  • Grape Kool-Aid (prepared – no sugar needed)


  • Place the funnel on top of the clear jar or pitcher. Line it with the coffee filter, and add the soil sample to the filter.
  • Slowly, pour the grape Kool-Aid through the soil filter. When it filters through, it will be a different color!

Agriculture Connection:

This activity visually displays the chemical charge of the soil sample you have. The grape Kool-Aid has two different colors of dye in it – red and blue. The red dye has a negative charge, where the blue dye has a positive charge. In soil, clay particles are negatively charged, and organic matter (like decayed plant materials) have a positive charge. That means that the soil particles will hold onto the different colors of dye depending on if there are large amounts of clay or organic matter or both! The charge of soil is important to farmers, because it impacts the types and amounts of nutrients that the soil can hold.

Safety School

Materials needed:


  • Help your students safely test the temperature of a whole cut of meat.
    • Point out the specifics of your family’s thermometer. Is it digital or analogue? Does it display safe cooking temperatures for different meats?
  • Help your student insert the thermometer into the center of the cut of meat and wait to get a reading.
  • Cross reference the reading from the thermometer with the safe cooking temperature guide.
  • Based on that reading, the type of meat, and the safe cooking temperature for that meat, have your student tell you whether or not it is safe to eat.

Agriculture connection:

Agriculture produces food, and food safety is a very important part of food production and food processing. Understanding how to cook food properly can help you waste less food and enjoy it more!


For some more great ideas on activities to do at home, check out our website at www.iowaagliteracy.org. What activities have you had success with at home?


Earth Day and Agriculture

No other industry uses the earth and relies on natural consistency as much as agriculture. Farmers require weather conditions that follow patterns year after year to grow their crops. They count on the soil to hold its nutrients to produce high yields. Farmers need fields to be in good condition to harvest, plant, chisel plow, and spread anhydrous or manure. Crop farmers aren’t the only ones affected by weather––livestock farmers can face extreme challenges when there is too much rain or snow, or in severe droughts or heat waves. The bottom line is this: farmers and ranchers rely heavily on the earth and the natural processes that help crops grow and supply food and water for their animals. The earth provides what farmers need to supply the world with food, clothing, and so much more.

Earth Day is on April 22, 2020, and in light of that, this blog post will highlight some of the ways that farmers are being stewards of the land they use and protecting the environment. Farmers are often ridiculed for the impact that agriculture has on the environment. To be fair, agriculture does have an impact on greenhouse gas emissions, like most industries. That is true. However, often the good things that farmers are doing to help protect our environment are overlooked, so that will be the focus of this blog post!

Cover Crops

A cover crop is a crop that is planted after a field is harvested. In Iowa, a farmer might grow corn in a field and plant a cover crop of cereal rye by using a high clearance seeder or by airplane in the early fall. These crops are not planted to make a great economic


Iowa Cover Crop

impact on the farmer’s bank account by growing and harvesting them, but rather to make a great impact on the environment and quality of the soil. Cover crops make the soil more absorptive, which allows for water to be soaked in the land instead of running off into streams. They also help with the runoff of nitrates and phosphorous. Nitrates feed plants, so they need to stick around in fields. Phosphorous is important for plants to perform essential functions like photosynthesis. In Iowa, the most common cover crops are cereal, radishes, oats, and wheat. Iowa farmers care about the land, and it shows, as the number of acres of cover crops planted has increased significantly in recent history. In 2017, Iowa farmers planted 1.5 million acres of cover crops! This information is from the Iowa Farm Bureau, and you can learn more about soil conservation from our previous blog post, Soil and Water Conservation Practices – What are they doing?


Livestock Health

It is no secret that cow eructations and flatulence (farts and burps) causes methane to be released into the air, which is a greenhouse gas, known for its negative impact on the atmosphere. However, there are a few things to think about that can help break down that problem. Farmers are now growing livestock much more efficiently than they did in the past. For example, we are now growing fewer cattle but producing more beef since 1980. This is a result of feeding cattle more nutritious feed and using selective breeding to grow higher producing cattle. (Introduction to Animal Science) There is also research being done on putting different fats like sunflower oil and seeds into cattle feed, which was found to produce less methane. Scientists have also been working on supplements and vaccines for cattle to help cut down on methane production. To read more about these studies, visit Health For Animals.

Windbreak Trees

Not only are farmers committed to helping the earth for their benefit, but they are also


Picture from Natural Resources Conservation Service

committed to making it more enjoyable for those around them. Windbreak trees are a row of trees that slow the wind. Windbreak trees are often seen near hog barns. They have been around for a long time, but their purpose remains the same. Stop the smell! This helps keep the neighbors happy, but there are other earth-preserving purposes behind the use of windbreak trees. One main reason is that windbreak trees save energy, which is an issue in our world today. Conserving energy is very important, and windbreak trees can help by saving 7-25% less fuel for heating, according to Iowa State University.


Technology in Farming

This is a broad topic, as technology has changed significantly over the past 100 years (you can read about it on our blog post, 5 Ways Technology Has Changed Farming), but one result is very obvious. Technology helps farmers do more with less. Using a GPS to plant or chisel plow now means using less fuel to do those jobs. Looking at soil composition in a field means that farmers can know what nutrients that soil needs to yield well, and can apply them in the correct amount, which can help with issues like runoff. Calculating a feed ration for cattle using technology means that they are fed a perfectly mixed ration, leading them to produce more efficiently. Pig barns are heated and cooled using technology, allowing the barn to use only as much energy as is needed.

This Earth Day, think about the people that use the earth to provide everyone with vital Pink Black Photo Brush National Kissing Day Social Media Graphicproducts. Farmers care about the earth, and they are taking measures to protect it. Earth Day may look a little different this year, but one way to celebrate is by taking time to learn about the earth and the people who use it, by listening to a podcast or reading a blog post! Happy Earth Day!



The Big Picture of Iowa’s Pork Production Cycle

Iowans are known for a lot of things. Kindness, die-hard loyalty to sports teams (go Cyclones!), and using the word “ope” instead of “excuse me”. However, there’s one more thing that Iowa is really, really good at: raising pigs. Iowa is the number one producer of pigs in the United States and in today’s post we are going to dive into the reasons Iowa can produce so many. The reason is all in one word- sustainability. Sustainability is defined as “the ability to be sustained, supported, upheld, or confirmed.” Iowa’s pork production is very sustainable, as we have the ability to uphold high levels of production, and have for a while now. The reason behind this is that pork production in Iowa is a circular cycle. Let’s take a closer look.

First of all, not only do we grow the pigs in Iowa, we also grow their food right here in Iowa. Pigs require a diet with two major components, corn for energy and soybeans for protein. Iowa ranks number one in corn production, and either number one or two for soybean production (that title alternates with our neighbors directly to the east).


Iowa is the #1 producer of pork in the U.S.

According to the USDA, in 2018, Iowa farmers harvested over 13 million acres of corn and nearly 9.9 million acres of soybeans. Pigs eating the crops we grow creates a cycle, which is part of the overall sustainability circle. Pigs provide a market for the crops, and crops are grown to provide food for the pigs.

Why do we grow the crops here? I’m glad you asked! Iowa is the perfect place for crop production of corn and soybeans due to our rich black soil, our climate, and the manure that we get from our livestock, which includes – you guessed it- pigs! Iowa’s topsoil is some of the best in the country- in fact, it is known as “Iowa’s black gold”! Our climate provides the temperatures and moisture that crops need during the growing season.

Now let’s get down to the matter of manure. This topic is an incredibly vital part of our sustainability cycle of pork production in Iowa. According to the Iowa Pork Producers Association, around 25% of Iowa’s cropland is fertilized by livestock manure. If you’ve ever driven by a farm and it smells particularly potent (manure-y), or seen a large tank with disks being pulled behind a tractor across a field, you’ve witnessed the pork production sustainability cycle in person.


Manure Spreader

 Manure can provide many benefits to cropland, including important nutrients like nitrogen, phosphorous, and potassium – the trio is often referred to as NPK – and it is very valuable to crop production. Manure can provide these elements for Iowa’s cropland, and the process through which it gets from barn to field is part of what makes Iowa’s pork production so special. The manure is pumped out of the pit underneath the barns into the big tanks. Then the farmer can take the manure and spread it in nearby land. The proximity of cropland and barns creates an easy access to spread good fertilizer on farmers’ fields. Farmers don’t like to haul manure long distances, and so being able to have the manure as close as possible to their land is important. This is a large consideration when farmers consider putting up new hog barns, and when they consider buying new farmland. 

Manure creates the ability to produce crops for a lower price, because farmers don’t need to purchase as much fertilizer. In turn, this preparesGray Bubble Cycle Diagram Chart the ground to grow corn and soybeans which will be fed to our pigs.  

Iowa is known for our pork production, and there’s a reason. The sustainability process of producing pork is incredible and allows us to produce the most in the country. Pork production benefits our economy, it allows us to provide more food, and it gives manure a great purpose!



Hello everyone! My name is Ellie Cook and I am the new Education Programs intern with Iowa Agriculture Literacy Foundation. I am from a family farm in Hubbard, Iowa, where we raise corn, soybeans, pigs, and cattle. I’m currently attending Iowa State University, where I major in Agriculture Communications. I’m very excited to be with IALF!


Why Soils are Important

942783176_083c95a60c_b.jpgIt is easy to understate the importance of soil. It seems benign. It seems inert. But the ground beneath our feet is literally teaming with life – most of it too small for us to see or register as important. But all of it IS important and vital to our human life systems. Soil provides the anchor to plant roots. It holds water and nutrients. It is home to micro-organisms and so much more.

When we think of soil, we often think of the physical properties of the soil. How big are the particle sizes? Sand is the biggest, silt is a medium size, and clay is the smallest. We think about the water holding capacity. Clay soils have a lot more surface area of the individual particles and so therefore can hold a lot more water than sandy soils. We think of availability of nutrients and soil structure as indicators of healthy soil. But it is these last two that offer a huge level of complexity that we rarely think about.

Nutrient availability

Whenever a soil is lacking in available nutrient for the given crop it is easy to consider adding an amendment. If the soil is low in nitrogen, then just add some ammonium nitrate and you are good to go. While this method offers a quick (and needed) solution to the immediate nutrient deficiency, it doesn’t take into consideration the complex biology of bacteria, nematodes, fungi and other microbes in the soil that play a role in nutrient cycling. In theory, with enough organic matter present in the soil and the right microbes in the soil, nutrients like nitrogen should be readily available for whatever crop or plants are currently growing.

38362547684_a5e3746e8a_b.jpgSoil structure

Soil structure shows up when soil clumps together and creates peds. These peds allow for cracks and spaces in the soil for water to permeate down and more easily get absorbed. Soil structure can take years and years to form and can easily be destroyed through mechanical cultivation. What causes soils to form these peds? It is largely due to the network of BIOLOGY in the soil. Plant roots send off tiny root hairs that can hold some of the bigger pieces of soil together. Fungi and their mycelium can act as little webs and nets that bind to the plant root hairs and bind to smaller pieces of soil. And proteins excreted from things like protists and other micro-organisms can act like glue that binds individual soil particles together. This inter-connectivity of many different organisms to create soil structure shows the need to pay attention to biology.

Functions of soil

  1. 6230526315_bc10fdf6da_b.jpgWe consider soil to have six major functions. First and foremost, soil is used for food and biomass production. Eleven percent of the globe’s land surface is used in annual crop production with up to 36% of land suitable for some kind of agriculture (livestock or crop). This land grows our food crops, it raises livestock, and it produces biomass like lumber for houses and paper, cotton for clothes, and biomass for fuel like ethanol. The soil is the anchor for the plant roots.
    • Consider that U.S. agriculture produces about 500 million tons of crop residue annually, most of which contributes to maintaining soil organic matter. Plans to use crop residues for bioenergy production could deprive agroecosystems of important inputs for future soil productivity, potentially upsetting existing agroecosystem balances.
  2. An essential function of soil is the storage, filtering and transformation services that it provides. Soil filters water removing harmful micro-organisms, chemicals, and other pollutants to make for clean and safe drinking water. We have created some artificial processes to clean water for drinking, but soil is still the most important filter for us. Soil can also store our garbage (landfills), it can store excess water (think of heavy rains and the soil absorbing that liquid), it can store carbon (living and nonliving matter in the soil store carbon that would otherwise be released in the air). Removing fossil fuels from the soil and burning them and releasing them into the air has shifted the balance and been a primary cause of global climate change. Soils can also facilitate environmental interactions to transform things. For example, bacteria that live in the soil transform atmospheric nitrogen into plant available nitrogen.
    • Wetlands and the soil in the wetlands deliver a wide range of ecosystem services that contribute to human well-being, such as fish and fiber, water supply, water purification, climate regulation, flood regulation, coastal protection, recreational opportunities, and, increasingly, tourism. Despite these important benefits, the degradation and loss of wetlands is more rapid than that of other ecosystems.
    • Consider that through natural processes, such as soil adsorption, chemical filtration and nutrient cycling, the Catskill Watershed provides New York City with clean water at a cost of $1-1.5 billion, much less than the $6-8 billion one-time cost of constructing a water filtration plant plus the $300 million estimated annual operations and maintenance cost.
    • Covering just 6% of Earth’s land surface, wetlands (including marshes, peat bogs, swamps, river deltas, mangroves, tundra, lagoons and river floodplains) currently store up to 20% (850 billion tons) of terrestrial carbon, a CO2 equivalent comparable to the carbon content of today’s atmosphere.
  3. 303107524_94683698cf_b.jpgAnother function of soil is as a biological habitat and gene pool. Soil provides the habitat for seeds to germinate and grow. It provides everything they needs like water, warmth, nutrients, etc. Soil provides habitat for a myriad of animals like worms, moles and insects, but also bacteria, protists, and fungi as well. All of these creatures come into contact with each other and can interact. The insects can mate and produce offspring. The bacteria can divide and reproduce. And sometimes when they do, they evolve and two species can share a little bit of DNA. One success story of this is when a sweet potato absorbed some DNA from a bacteria. This horizontal gene transfer can make the plant resistant to diseases.Consider that there are more living individual organisms in a tablespoon of soil than there are people on the earth.
    • Almost all of the antibiotics we take to help us fight infections were obtained from soil microorganisms.
  4. Functionally, soils are also a source of raw materials. For much of modern human history, ceramic dishes made from clay were the primary tableware. Only in very recent years have we started using more glass, plastic, and one-time-use dishes (styrofoam). Soil can also be the source of countless minerals through mining processes. Soil can also be used for bricks and other materials in building houses.
  5. 5186540530_98ebc01950_b.jpgSoils can also play a functional role in our physical and cultural heritage. Around the world soils have  been shaped for things like effigy mounds potentially for religious ceremonies, burial ceremonies, or other purposes. Soils also protect our cultural past. Artifacts that get covered up by soils can be protected from the elements creating a bookmark and window into our past and heritage.
  6. Finally, soils can serve as a functional platform for us to build our structures on. Whether it is houses, highways, skyscrapers, or football fields, we need a base of soil to provide the stability to build on. Even things like bridges over water, still go down to the soil at the bottom of the river or lake to rest on.

So, could we live without soil?

Sure, we could produce food through things like hydroponics and aeroponics. But without soil we couldn’t produce the amount of food that we need to sustain human life for all seven-plus billion of us. Sure, we have figured out other ways to filter water and store garbage. But our water filter systems haven’t been scaled up to do what soil does naturally. And garbage management systems like burning garbage has other negative environmental repercussions. Without soil countless organisms like moles, worms, bacteria, and fungi would be without a home. Most of those creatures are uniquely adapted to live in soil. Without soil we wouldn’t have the raw materials we need or the base to build our structures. In short, the answer is no. We couldn’t live without soil.

Soil is easy to overlook and some may even call it dirt. But soils are important for many reasons and as farmers and agriculturalists we can protect and improve soils for the betterment of all.


Nutrient Cycling in the Environment

general cycling

“The nation that destroys its soil destroys itself.” This quote by Franklin D. Roosevelt simply explains the importance of managing soil quality. This becomes extremely applicable to farmers who are trying to maximize crop production, which can be achieved by maximizing the productivity of their ground. Fields contain much more than just dirt. They’re a complex ecosystem that contains a large amount of diversity when it comes to chemical and biological composition. One major factor in soil’s productivity when related to crop production is the nutrients found in soil. Some nutrients come from organic materials that are naturally occurring, while others are added to the soils because they are deficient. This process becomes a bit complicated when talking about specific nutrient cycling. This post will showcase how nutrients move throughout the environment while shining a light on the importance of managing soil nutrients. 

How do nutrients cycle in the soil?

Nitrogen (N)

Nitrogen is a macronutrient required by all plants, and is especially correlated with high yields in corn and soybean production. But first here’s a little bit about the basics of nitrogen in a cropping system! 

  1. Nitrogen gas (N2) is abundant in the air, however it cannot be taken up by plants. The plant available forms of nitrogen is nitrate (NO3) and ammonium (NH4+). 
  2. Nitrate is mobile in the soil profile. Due to this molecule’s negative charge, it repels from negatively charged soil particles and is easily lost to leaching and soil runoff. 
  3. Plants use nitrogen to synthesize amino acids, proteins, and chlorophyll. Ammonium is the easier form of nitrogen to use because it requires less energy in the reduction process. 


This diagram helps to visualize each process in the nitrogen cycle. Photo from wikiwand.

Now that we understand the importance of nitrogen in crop fields, here’s how it cycles and moves around in the environment! Nin the atmosphere goes through ammonification to become NH4+, which occurs due to nitrogen-fixing bacteria found in the soil. Legume roots have a symbiotic relationship with these bacteria, which adds plant available N to a field. Once in the ammonium molecule, nitrifying bacteria changes NH4to nitrites (NO2) and then nitrates (NO3). From this point, the molecules can either be taken up by plants, processed back to N2 through denitrifying bacteria, or leached with water. If the soil’s natural amounts of nitrogen is insufficient for a specific crop, the producer can apply fertilizers to a field.  It’s important to remember that these processes are constantly changing the chemical makeup of a soil, and that severe weather events could deplete the soil of many plant-available forms of nitrogen. 

Phosphorus (P)

Phosphorus is another essential macronutrient that’s found in phospholipids, lipids, and the backbone of DNA.

  1. Crop grain contains a large amount of phytic acid, which is primarily comprised of phosphorus molecules. 
  2. Phosphate is the plant available for of phosphorus, and the two most common forms of P are HPO4-2 and H2PO4

P cycle

This diagram helps to depict and simplify the chemical changes that occur in the phosphorus cycle. Photo from soilmanagementindia.

Unlike nitrogen, phosphorus’s most abundant form is a solid found in the ground. Organic P is created over an extremely long period of time with plant residue, hummus, and microbial biomass. Organic P is turned into a plant usable form through mineralization, and the reverse reaction is called immobilization. Once phosphorus is available and held in solution it can become unavailable by reacting with clay and various mineral surfaces or by binding with cations such as calcium, iron, and aluminum. Phosphorus held in solution is susceptible to leaching, much like nitrogen is. It’s important to know that the main P inputs into ecosystems are derived from fertilizers and plant residue. 

Potassium (K)

Potassium is a macronutrient that’s required for protein and starch synthesis, acid neutralization, enzyme activation, as well as water regulation in plants. 

  1. Plant available potassium is K+. Some soils can contain a lot of potassium, but not in the cation form. 
  2. If a plant is deficient in potassium, it can exhibit stunting, necrosis, lodging, and an overall reduction in yield. 

K cycle.jpg

This photo showcases the major steps and processes in the potassium cycle. Photo from nutrien-eKonomics.

Potassium starts as a primary mineral such as mica. After years and years of weathering, it changes into a nonexchangeable form. K cations change between nonexchangeable and exchangeable molecules through release and fixation. Once K is in an exchangeable form, it changes into a plant available form through desorption. K in solution is able to be leached, but is much less susceptible than nitrates. In terms of mobility within the soil profile, potassium is immobile. This is because a large percentage of soil K is nonexchangeable, due to its location and attraction to soil minerals. The main inputs of potassium into systems is through fertilizer and plant residues. 

How are these cycles manageable? 

Since these cycles are constant and on-going, it’s crucial for producers to maintain a knowledge of the nutrient levels within their fields and which areas are the most susceptible to losing nutrients faster than others. One way to measure nutrients is to test the plant’s vegetative matter for chemical composition. While these results are helpful and accurate, it doesn’t necessarily provide information for the available forms within the soil. This is where soil testing comes into play! Soil tests can be used to qualitatively measure nutrient levels precisely, which helps to give producers recommendations on management practices in the future years. 

Hopefully this opened your eyes a little to the vast possibilities within soil science, as well as provided a better understanding of some prominent nutrients that cycle through ecosystems!