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. 
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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. 
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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!

~Rosie

Macronutrients in Crop Production

elements in the environment

When growing crops of any type, it’s important to understand the required inputs in order to receive the desired yields. One of these inputs, arguably the most important and critical one, revolves around nutrient management. All plants have these requirements, whether it be crops grown for biofuels, fruit production, or landscape ornamentals. Each plant needs various amounts of nutrients, which can be used to classify them (by quantity) into macro or micro nutrients. It’s important to remember that each one is vital for plant growth, simply required in different doses. As a sidenote – this blog is going to be mainly focused upon corn production, but all of these elements are necessary for any plant you’re trying to grow! First I have a couple questions to spark your curiosity about nutrients in plants…    

  • A plant can be deficient in oxygen, how is that possible?
  • Plants need calcium just like humans do. If it doesn’t go towards bone and teeth strength, then what’s its purpose?

Macronutrients

Let’s start with the big three: carbon, hydrogen, and oxygen. If you’re reading a fertilizer label, they don’t typically advertise for these elements. So, where do plants take them from? Why are they necessary for plant life? Should I be worried that my garden isn’t receiving enough hydrogen? The simple answer is that no one should be concerned about their plants being nutrient deficient in C, H, or O, as long as the plants are surrounded by air!

Carbon (C) – Thanks to many fields of science, we know that carbon is the base for life on Earth! This means that if plants are going to continue to be alive, they must obtain and maintain C. In more direct terms, plants produce and uses chains of carbon with other atoms called carbohydrates, lipids, proteins, and nucleic acids. But what happens if the plant is unable to take in carbon? This would be a very unfavorable scenario for the plant, especially since carbon is essential to photosynthesis. More specifically, without carbon (in the carbon dioxide form) the Calvin cycle wouldn’t occur. This means there’s no G3P, which helps make glucose, and without energy the plant cannot continue to live.

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This depicts the Calvin cycle in photosynthesis. Diagram from Khan Academy

Hydrogen (H) – Whenever I think of elemental hydrogen, I don’t normally think of it as a nutrient. I don’t directly eat anything that is marketed as “high in hydrogen”, so how could a plant use it? To start off with, every living organism on Earth needs water (H₂O) to live. Plants use water to obtain hydrogen atoms when splitting H₂O molecules through the light reaction of photosynthesis. The hydrogen ion is then used to create NADPH, which is a crucial ingredient in the Calvin cycle. If a plant is missing this chemical compound, then photosynthesis would cease and the plant would die.

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This shows the light-dependent reactions in photosynthesis, commonly referred to as the z scheme. Image from LibreTexts

Oxygen (O) – Wait a minute – oxygen is a product of photosynthesis, why would a plant need to take in oxygen too? In order to break down food through aerobic respiration, there must be oxygen present. Yes that’s right, plants respire just like humans do! Cells within leaves and stems obtain oxygen atoms that are a product of photosynthesis. However, cells found in areas that aren’t photosynthetically active must find oxygen elsewhere. To solve this issue, roots are able to take in O₂ from the air between soil particles. If the ground is saturated to capacity, then the roots cannot take up oxygen in the gas state. If the area is flooded for longer than 72 hours, it’s likely the plant will run out of oxygen and not recover.

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The chemical equation for photosynthesis.

Nitrogen (N) – This is a much more commonly discussed nutrient, especially since it has a huge correlation to high yields in corn production. If you were to walk into a farmer’s field, you would be surrounded by nitrogen in many forms! N₂ is a gas found in the air, whereas NO₃⁻, NH₄⁺, and NH₃ are compounds found in the soil. But if nitrogen is found in the air, why can’t corn absorb it like carbon or oxygen? This is because corn can only take up nitrogen when it’s in a nitrate form, which can be found in solutions and attached to soil particles! When taking a closer look at NO₃⁻, it’s more prone to being lost to the environment due to its negative charge. Soil naturally has a negative charge, which means that a nitrate is more likely to move elsewhere in the environment than wait around to be absorbed by a plant. This is why many agriculturists use anhydrous  ammonia as a N fertilizer, because it contains NH₃ and not NO₃⁻. Overtime soil microorganisms will convert ammonia to a plant available nitrate. Why is nitrogen so important in corn physiology? N is essential to grain fill and development. This means that if the plant is deficient in nitrogen, the kernels and ear won’t fill to their genetic potential. A common symptom of N deficiency is a yellowing midrib on a lower leaf.

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Nitrogen deficiency in corn. Photo from SDSU Extension

Phosphorus (P) – This is another very important macronutrient! In a similar respect to nitrogen, plants are unable to absorb and utilize the elemental form of P. This creates a problem in fields, because P is most commonly found in a plant unavailable form! Luckily, roots have a symbiotic relationship with Mycorrhizal fungi which are able to turn P into a more usable form. Corn can easily uptake phosphates, and the most common compounds are H₂PO₄⁻ and HPO₄²⁻. Since phosphates have negative charges, they are more prone to leaving the soil than the elemental form (similar to nitrates). This is why synthetic fertilizers that contain significant amounts of phosphorus are delivered in a P₂O₅ compound. Why is phosphorus so important in corn physiology? P is directly correlated to crop maturity, yields, and overall plant growth. More specifically phosphorus is a huge makeup of sugar phosphates, which directly affects ATP. Energy transfer with ATP is crucial, due to it’s role in both RNA and DNA. A lack in P will affect the overall efficiency of any plant. Phosphorus deficiency in corn appears in older leaves and starts as a purple hue. An increase in severity will turn leaf margins brown.

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Phosphorus deficiency in corn. Image from Channel.

Potassium (K) – When applying synthetic fertilizers, it’s common to see potassium in the K₂O form. However, this form is not immediately available to plants. Plants can only take up K+ when it’s in a solution. This form differs from the available compounds of N and P, since potassium is a cationWhy is potassium so important in corn physiology? A deficiency in K can have a multitude of negative affects upon the plant. This could be seen as an increase in susceptibility to drought, temperature stressors, and pests. Agronomists refer to K as “the quality nutrient”, meaning there’s a direct connection to traits like seed vigor, size, color, and shape. To be more specific, potassium helps build cellulose, increase protein content, maintain turgor, and move sugars and starches throughout the plant’s vascular system. K deficiency symptoms start as a yellowing of leaf margins on older leaves, and an increase in severity turns the pale color to a brown necrosis.

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Potassium deficiency in corn. Photo from Thompsons.

Secondary Macronutrients

There are three elements that fall under this category, as they’re needed in higher quantities than micronutrients but lesser amounts than N, P, and K.

Calcium (Ca) – Calcium deficiencies are most common in sandy and/or acidic soils, since the Ca ions can be leached through the soil profile. Similarly to potassium, Ca²⁺ can only be imbibed by plants when in a soil solution. Why is calcium so important in corn physiology? Ca holds a vital role in the creation of cell walls and membranes. Calcium deficiency symptoms are visible in new growth, so in corn this would be around the growing point. It typically appears as a yellowing color, slowed growth, and leaf tips sticking together.

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Calcium deficiency in corn. Image from Crop Nutrition.

Magnesium (Mg) – Without Mg, a plant would not be able to photosynthesize. This element is a sizable component within chlorophyll molecules, which is 100% necessary for capturing the sunlight’s energy! Additionally, Mg serves as a phosphorus carrier. Simply put –  if there’s not enough Magnesium then the plant would be unable to uptake P, even if it was available in the soil! Mg²⁺ is the plant available form, and can be heavily affected by the pH and sandiness of soils. Mg deficiencies are first seen in older and lower leaves, starting as a purple interveinal discoloration.

Mg deficiency.jpg

Magnesium deficiency in corn. Photo from The Mosaic Company.

Sulfur (S) – The last, but certainly not least, macronutrient can be absorbed both through the roots and stomata openings. In the environment, sulfur is commonly found in the air as SO₂ and within soil solutions as SO₄²⁻. Unlike the previous secondary macronutrients, this one is taken up as an anion as opposed to a cation. Due to the negative charge on a sulfate molecule, it is mobile in the ground (just like nitrate or phosphate) and can be leached through the soil profile. Why is sulfur so important in corn physiology? Without adequate S, some amino acids and proteins would be unable to synthesize. Sulfur also has a connection to winter hardiness, which is a major trait in certain crops. S deficiency in corn appears as a general yellowing of younger leaves, starting between veins but widening to encompass the entire leaf with increasing severity.

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Sulfur deficiency in corn. Image from Successful Farming.

This is merely a glimpse into some of the chemical factors and management systems that a row crop grower oversees each and every year. If you liked this blog or learned something new from it, let us know! Or maybe if you’d like to see a similar breakdown of micronutrients too? Either way I love writing about agronomic science and can’t wait to share another blog with you all!

-Rosie

 

Fueling the Body

Conventional wisdom encourages marathon runners to fuel up by eating a lot of carbohydrates. Bodybuilders pump iron and eat a lot of extra protein in their diet. Even nursing mothers need a special diet and bloggers recommend everything from oatmeal and flax seed to brewer’s yeast and fenugreek to help produce and let down milk for the newborn.

The science is a bit mixed on each of these and doesn’t prove that they work the way proponents claim. It stands to reason that marathoners need a lot of energy. Carbohydrates convert to sugars in the body which can be used for quick energy in metabolism. Bodybuilders are trying to build muscle and so an increase of protein and amino acids to build that muscle should be beneficial. For nursing mothers, the oatmeal could provide some iron as they are often anemic with low iron levels in their blood. The flax seed can provide some healthy fatty acids and the brewer’s yeast can be a source of B-complex vitamins, protein, minerals, and chromium. The bottom line is that whether you are running a race, pumping iron, or nursing a baby you need to give your body what it needs for peak and optimal performance.

The same is true for livestock. Farmers are constantly looking for ways to keep their animals healthy and well cared for. The diets they select for their livestock are usually recommended by a veterinarian or animal nutritionist to provide optimal performance. Dairy cows need a diet that will help them produce a lot of milk. Pigs, turkeys, and beef cattle need a diet that will help them grow big and pack on muscle mass. Chickens need a diet that will help them lay eggs.

IMG_3040.JPGDairy Cattle: To keep dairy cattle healthy and producing milk, their diet should include a lot of high-quality forages and grains. The forages (think corn stalks, grasses, alfalfa) provide fiber in the diet. This can come in the form of wet forage like silage (fermented forage) or dry forage like hay. As ruminants, a healthy gut biome is important and the cattle will regurgitate that forage, chew their cud and then swallow it and continue digestion. Bacteria in their stomachs will help break down the thick plant cell walls and extract the nutrients. Grains like corn, soy, wheat, etc. can provide quick energy and carbohydrates to fuel their body. A healthy diet will then include a balance of rations to meet other nutrient requirements (different for each stage of lactation). These nutrient requirements can include added fats, vitamins, minerals, protein supplements, and salt. It can actually be quite complicated with mathematical formulas to determine the exact amounts. The human diet is quite varied and therefore it is hard for nutritional experts to say exactly what a human should eat to stay healthy. But for cows who basically eat the exact same thing every day (grasses) experts can tweak the ration and provide exactly what they need to stay healthy and produce great quality milk (and a lot of it)!

PorkFarm-101.jpgPigs: Pigs are more omnivorous, meaning they can have a more varied diet like humans. This means that farmers can have more flexibility, but it also means that the math can be more complicated. The goal is to get the pigs to grow quickly and put on lean muscle mass. Current consumer trends want to see lean cuts of pork and so the lean muscle mass is important. That lean muscle mass is largely determined by the pig’s diet. Pigs can be fed molasses, beets, cane, oats, grain, groat, peas, rye, milk, sorghum, soybeans, eggs, fish, flax, meat and bone meal, canola, barley, alfalfa, sunflower seeds, wheat, and whey. Their ration is often then supplemented with protein, meal, vitamins, and minerals. For muscle production, farmers are trying to ensure pigs get enough essential amino acids like isoleucine, lysine, methionine, threonine, tryptophan, and valine. In Iowa, because it is readily available, the major feed components for a pig’s diet are corn and soybeans.

IMG_5123.JPGBeef cattle: Like dairy cattle, beef cattle need a lot of forage. But because their purpose is to produce muscle mass, like pigs, they might be supplemented with some added protein. Beef cattle will spend the majority of their life grazing grasses, as ruminants they are excellent at digesting those grasses and converting them into energy and ultimately muscle mass. While on pasture, they are provided mineral and salt lick blocks that can provide minerals like calcium, phosphorus, magnesium, sodium, and selenium. Most beef cattle are grain-finished, which means that they are transported to a feedlot where their diet is more closely regulated. Their diet still is largely forage, but farmers add in corn, soybeans, and other grains. This allows the animals to put on additional weight and even some fat which promotes marbling in the muscle which makes it taste really good when cooked. Corn and soybeans help provide the additions to their forage diet. Many cattle that are raised on pasture in the West are shipped to the Midwest to then be finished on grain. It is easier and more cost effective to ship the animals to the grain than to ship the grain to the animals.

EggFarm-076.jpgChickens: Chickens, like most animals, need a healthy mix of the basic nutrient requirements like carbohydrates, fats, proteins, vitamins, minerals, and water. Their exact nutrient requirement is tailored to their age and the stage of egg laying that they are in. Corn and soybeans can provide most of the nutritional requirements for chickens. Those base ingredients can be broken down into the specific nutrients that chickens need for optimal egg production including protein, lysine, methionine, tryptophan, and threonine. Then the diet can be supplemented with vitamins and minerals like calcium, phosphorus, sodium, and chloride. Calcium is very important for producing the shells of the eggs, so this becomes a key ingredient to add to chicken feed. Human nutritionists are also looking for ways to make eggs healthier to eat. If we supplement chicken feed with lutein that lutein will end up in the eggs. Lutein can potentially help in humans with brain development and eye sight. Other additives to chicken feed could make eggs even healthier for humans to consume.

So whether you are a farmer trying to care for your livestock, a runner, a weightlifter, or a sleepless parent trying to nurse a baby, fueling the body is an important piece of the puzzle to ensure health and optimal performance. Science is making new discoveries everyday and farmers are working hard to implement best management practices to feed and care for their livestock.

-Will

Why Do They Do That? – Crop Scouting

crop scoutLast summer my time was spent walking the corn and soybean fields of Southeast Iowa searching for weeds and pests that did not belong in the field. But why was I needed as a crop scout? Farmers’ livelihoods depend on their crops. Weeds and pests can easily overtake the field if not carefully controlled. It was my responsibility as a crop scout to identify the weeds and other possible concerns in the field and inform the farmer.

So what are crop scouts looking for in the field? First they look for any abnormalities in the plant. When plants are off-colored, chewed, stunted or dead, that could indicate issues that the farmer needs to be aware of. The causes could be soil, pest, or nutrient related, but it is important to determine the cause of the problem so it can be solved quickly.

The purpose of scouting is to give a representative assessment of the entire field. While scouting, it is important to look at multiple areas of the field. It depends on the size of the field for how many samples are taken. The rule of thumb is to check a minimum of five locations in fields of less than 100 acres. In fields greater than 100 acres, a minimum of 10 samples should be taken. Taking random samples is imperative to having a representative assessment of the field. Scouts do not just focus on the entrance, edges, waterways, high, and low areas, but rather randomly select various spots in the field to collect samples and stand counts. 

A crop scout keeps busy early in the season identifying weeds that are in the field. Scouting for weeds before planting seeds allows the farmer to know what weeds are growing in the field, the growth stage of the weeds, and the weed populations. Controlling weeds before they reach four inches tall can help eliminate yield loss. After the weeds have grown over four inches tall, they are harder to control.  Knowing what weeds are in the field allows the farmer to make better management decisions while it is easier to combat the weed issue in the field.

Scouting after the seeds are planting can show farmers seed damage, early pest damage, and many other factors. When plants start emerging, taking stand counts helps the farmer decided if they need to replant. They can also evaluate their management decisions and make changes for next years planting season. When taking a stand count measure 1/1000 of an acre. This measurement can be found by using the table below. Then count the number of plants in the measured area. Take at least six samples throughout the field. Then take the average number of plants and multiply it by 1,000 to calculate the final plant population per acre in the field. Most farmers plant corn at a rate of 29,000 to 38,000 seeds per acre and soybeans at a rate of 130,000 seeds for 21 inch row spacing and 210,000 seeds for 7 inch rows per acre based on 90% germination and 90% emergence rate.

crop row spacing

Crop scouts also keep a watchful eye out for insects. The scout must identify the insects present in the field, what ones are harmful, the amount of insects, and assess the damage caused by the pests. Damage can be seen by observing the foliage, seed heads and pods, stems and roots. By swinging a net over the top of the crop canopy, scouts are able to capture insects in the net and get an accurate estimate of how many insects there are per square meter. Inspecting the top individual leaves for insects can also be done in addition  to using a sweep net. It is important to observe the stem and roots to look for any signs of damage. Punctures on the stem can indicate insect damage. Signs of chewing can be an indication of insect damage even when you do not see any insects at the time of the scout.

Knowing the symptoms of plant diseases, is another important skill for crop scouting. Plant diseases can be caused by weather, fertilizers, nutrient deficiencies, herbicides, and soil problems. Watch this video for a quick rundown of corn diseases from an Iowa State University Field Pathologist.

Farmers want to make sure they know what is occurring in their fields, so they are sure to scout for weeds, pests, and diseases. Next time you drive by a corn or soybean field, take a look to see if there is someone out scouting a field.

Laura

P.S. Did you ever spend time walking fields as a crop scout? Tell us about your experience in the comments below.

How Many Ears?

How many ears will you find on a stalk of corn?

The question seems simple enough. Often times, cartoon drawings of corn plants show bountiful plants with six or eight or more ears of corn – one with every leaf. But the reality is much different. How many ears of corn on a single stalk? The short answer is….one.

But as Paul Harvey would say…and now, the rest of the story.

How many ears on a single stalk of corn? It depends! Corn or maize is a grass and like other grass species it has the possibility of producing tillers (stems that grow after the initial parent shoot grows from the seed) or branches. In the case of corn, the branch is called the shank which is a small stalk-like structure that grows out from a leaf node. Leaf nodes in the middle of the stalk have the potential of growing these shanks. It is from this shank that an ear of corn will grow.

One factor that will influence ear production is population density. Over the last half century, farmers have been able to plant corn plants closer and closer together. This allows for more total production and more bushels of corn per acre to be harvested. As the plant’s genes interact with its environment the plant will respond. More light, water, and nutrients will produce more branching. In high density populations (like in a typical cornfield) light doesn’t get all the way down and so there is less branching. The plant can dedicate all of its resources to producing one really good ear of corn rather than wasting water and nutrients on producing multiple, less viable ears. The corn plant’s main goal in life is reproduction and it wants to give its seeds the best chance of survival. One ear of corn with 600-800 seeds is better than two ears with only 200-300 seeds.

In modern cornfields in the U.S., farmers may plant 30 inch rows with 30 to 35 thousand seeds per acre resulting in that many individual plants. Some farmers are planting 12 inch rows with as many as 60,000 plants per acre! Soil and available nutrients have to be able to support that many plants, and each farm and each field is different. Corn varieties that farmers use today have been selected and bred for high densities, meaning that they can tolerate high populations and usually only produce one ear per plant.

But in the right conditions things could change. If those high density varieties of corn (or any other cultivar of corn) are spaced out with low competition, plenty of sunlight, water, and nutrients, they could branch more and produce more ears of corn. Often times, farmers will see more ears at the edges of fields because the end rows have more sunlight and more space. But the second ear will not usually be as good of quality. The primary nutrient that is a limiting factor for overall growth and ear development is nitrogen.

Sometimes farmers can increase the population of corn planted and actually decrease the number of ears. Some plants would be barren and not produce an ear. If the farmer is growing the corn as stover (stem and leaf materials) to feed to livestock as chopped silage, there is no need to produce a large ear.

Of course with all of this, we are primarily talking about field corn (also called dent corn). Field corn accounts for 99% of the corn grown in Iowa. Field corn can be used for human food (tortilla chips, cornbread, etc.), animal food (both ground corn and fresh silage), and fuel production (ethanol and corn oil biodiesel).

Sweet corn, the kind that we enjoy fresh off the cob in the summer, is sometimes considered a low-value crop when compared to other vegetables. This is because it takes up valuable room – a lot of room – in a garden and only produces one ear per plant. Sweet corn can take up to 3 square feet of space. If you harvest a cucumber from the garden, more will grow and you can get multiple harvests. But if you pick an ear of corn, the plant is done producing. Sweet corn may produce two or sometimes three ears per plant because there is wider spacing and less competition. Early maturing sweet corn varieties may still only have one ear. Later maturing sweet corn varieties might have multiple ears.

So, don’t believe those cartoon drawings! Corn usually only has one ear per stalk.

And now you know the rest of the story.

-Will

 

6 Reasons Farmers Use Cover Crops

There is a challenge that farmers are faced with every day of their career—how do we protect the land we work on? Farmers work with the land everyday of their lives and work to protect and restore the land for future generations. They understand how the land provides for them—after all, without taking care of the land they work they would not be able to grow a product, such as corn and soybeans, and be able to make a profit for their livelihood. One way farmers work to protect the land is through cover crops.

What is a cover crop? This is a plant that is grown in fields to protect land quality for the future. There are many benefits of implementing the use of cover crops—and here are 6 reasons farmers use cover crops in their operation.sloans-cover-crop-in-corn-stubble

1.)Soil Erosion: One thing I will always remember from my American History lesson of the Dust Bowl is that bare ground is not the answer. Open topsoil is something to avoid in farming practices. Wind and water can carry the soil away through erosion. My dad always said that we can’t rebuild the soil, and he’s right—it takes many years to produce organic matter that makes up Iowa’s rich topsoil. By planting cover crops we help stabilize the soil and protect the topsoil layer by not exposing it to erosion by wind and water.

2.)Nutrient Management: Cover crops are a great way to add valuable nutrients back to the soil. Not only that but cover crops also add back organic matter to the soil as they decompose. In my agronomy class at Iowa State University, I am learning how certain types of legume plants have the ability to ‘fix’ nitrogen in the soil, such as hairy vetch and winter peas. Nitrogen is an essential element in plant growth. By adding in certain cover crops we are also adding in ways to produce nitrogen. Adding in nutrients is not the only benefit, but also balancing nutrients in the soil is a great perk of cover crops too. Adding in certain cover crops, such as non-legumes cover crops (radishes and rye), also have the ability to tie up the nutrients and prevent them from runoff or leaching. Which leads us into our next reason, water quality.

3.)Water Quality: With nitrogen in the soil also comes nitrogen runoff—both which farmers work towards maintaining. Our water streams are easily exposed to nitrogen runoff and other pollution sources. Not only do some cover crops help produce nitrogen, but others like, radishes and rye, also work to lock in nutrients and keep them from producing runoff or leaching. If you think about it, cover crops work as an extra filter system on fields.

4.)Biodiversity: Not only are farmers introducing a new plant onto these fields, they also introduce new interactions of all types of life. Cover crops bring in new habitats, they bring in beneficial or repelling insects, they attract wildlife, and provide protection against wind and water erosion. Creating an area of diverse species only boosts the circle of life and provides new opportunities to grow.

5.)Weed Suppression: Competition is a real thing in the plant world and farmers use cover crops as a way to eliminate weeds from their fields. Roots of cover crops extend deep down into the soil to take up any nutrients or water available. While doing so they also ‘weed’ out other weeds (no pun intended) for those nutrients. Not only do cover crops compete with weeds below the soil surface, but they also compete above the surface for sunlight and space. The competition from cover crops is too stressful for the weeds to handle, making it easy for farmers to have complete weed control.

6.)Green Pasture: Some farmers who also have cattle also have the option of grazing their cattle on the cover crop fields. Its just another way farmers can save feed costs. Cattle love to graze on certain forages, especially crops like clover, radish tops, and rye. Not only can the farmer feed his cattle, but he can also fertilize his fields in the process. The cattle’s manure makes a great source of fertilizer—so basically it’s a two for one deal here.screen-shot-2017-02-07-at-11-47-14-am

There are many reasons why farmers use cover crops—each reason presents an opportunity to improve soil and land quality for the future. Now you may wonder why not all farmers use cover crops. Well even though there are benefits there are also challenges. Cost is a big challenge facing farmers and one of the key reasons that they do not use them. Although cost takes a toll in the present, the benefits can outweigh the costs for the future. For example adding in nutrients and managing weeds work to boost yields, not to mention protecting the topsoil works to help plant growth too. A farmer may be faced with many challenges each day, but they also know how they can work to make the best decision for their operation as well as for the land to be worked on in the future.

-Hannah Pagel

Fertilizing – Why do they do that?

We all know that plants need nutrients to grow. But don’t they get those nutrients from the soil? Why do farmers need to apply fertilizer?

You might hear Iowa farmers talking about ‘applying manure’ or ‘dragging anhydrous’. What they are really talking about is the application of fertilizers to fields with the hopes of increasing crop productivity. All plants need a variety of nutrients to grow and be healthy. A lack of any one nutrient might cause symptoms like yellow leaves or brown spots or other unhealthy symptoms like wilt or susceptibility to diseases like mold or insects.

Plants need a whole host of nutrients to stay healthy. They need micronutrients like boron (B), carbon (C), chlorine (Cl), copper (Cu), hydrogen (H), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), oxygen (O), and zinc (Zn). Recycling plant matter is an excellent way of providing micronutrients to growing plants. They also need secondary macronutrients like calcium (Ca), magnesium (Mg), and sulfur (S). But plants need the most of primary macronutrients which are N-P-K. These nutrients are usually lacking from the soil because plants use large amounts for their growth and survival. The three primary macronutrients are nitrogen (N), phosphorus (P), and potassium (K).

26e53c8Nitrogen is part of all living cells and helps transfer energy in plant cells. It is part of chlorophyll which makes the plants green and allows them to produce food through photosynthesis. Nitrogen supports quick plant growth and maintains strong leaves and good fruit production. Nitrogen can be fixed from the air through the nitrogen cycle or it can be added to fields in the form of fertilizer.

Phosphorus is also an essential part of photosynthesis. It helps the plants form oils, sugars and starches. Phosphorus aids in turning solar energy into chemical energy and helps the plant withstand stress.

Potassium benefits plants in building protein and producing high quality fruit. It also helps plants be more resistant to diseases.

Soil can hold some of these nutrients in place so that they are available to the plants when the plants are ready to use them. So often times farmers will apply manure (high in organic matter and nitrogen) or anhydrous (high in nitrogen). Because the soil can hold these nutrients, farmers can take advantage of slower seasons like the fall (after harvest) or spring (before planting) to apply fertilizer. But soil can’t hold an infinite amount of these nutrients. If there is too much nitrogen it can leach into waterways with a big rainstorm. Nitrogen in water can be a problem for wildlife and humans that rely on that water.

27067Farmers try very hard to only apply the correct amount of fertilizer. Too little and the corn or soybeans won’t grow well. Too much and the nitrogen will be wasted and potentially run off into the watershed. Precision application can use soil testing data to apply fertilizer only to the parts of the field that need it.

Anhydrous ammonia application in the fall should be done after the soil temperature is below 50 degrees Fahrenheit (usually around the first week of November). This prevents nitrogen losses from leaching. In the spring it is best to apply nitrogen within two weeks of planting the crops to avoid loss.

Once the crop is growing it may need some additional fertilizer (nitrogen) to maximize growth and yield. Even legume crops like soybeans (that have nitrogen fixing bacteria) sometimes need some extra nitrogen to help them grow. In that case it is important to apply the fertilizer as close to the period of maximum crop growth as possible. This ensures that it is available for the plant and won’t leach into the waterways.

Soil-water-conserv-weekApplying fertilizer takes a lot of scientific understanding of plant physiology, the nitrogen cycle, soil testing, and good management decisions. But with good management of fertilizer, crops can produce their maximum yield and we can still protect water quality here in Iowa. This is one small way that farmers celebrate Soil and Water Conservation Week – April 24 through May 1, 2016!

-Will

What’s Cookin’? Winter Brussels Sprouts

New year equals new resolutions. If you are anything like me and millions of other Americans your New Year’s resolutions include either eating better or exercising more (or both)!  Sometimes in the winter months I’m not as good about eating my veggies. With short days, when I get home from work the last thing I want to do is spend a lot of time cooking. But, I need to stop making excuses. There are some great winter vegetables that are nutritious, delicious and easy to get on the table in as little as 20 minutes. Here is my new favorite side dish – Winter Brussels Sprouts – and the agriculture story behind it.

Brussels sprouts, close up

Brussels sprouts – This underrated vegetable might be loathed by kids, but is actually really tasty. A lot of people don’t like them because they can smell bad if overcooked. Overcooking can release a natural compound that contains sulfur which stinks, so be sure to only cook them until easily pierced with a knife. The plant is said to have been originally cultivated in the area that is now Belgium and was named after the capital city. They are very nutritious and a great source of vitamins A, C and K as well as folic acid, iron, magnesium, selenium, and fiber.

wild-mustard-plantBrussels sprouts are descended from the wild mustard plant Brassica oleracea just like cabbage, kohlrabi, kale, broccoli and cauliflower. Brussels sprouts were bred and selected to promote lateral buds that grow up along the stem. Other members of this family were selected for their terminal buds, large leaves or flowers. While not GMOs, this family of vegetables is a perfect example of breeding and selecting for desired traits. From one common ancestor agriculturists were able to make a variety of veggies we all know and love.

rustic cooked bacon

Bacon – Mmmm….bacon… This tasty pork product comes from the side and belly of the pig. Pork bellies are cured in a salt brine and flavorings to provide the rich taste. The curing process evolved before refrigeration as a way of preserving the meat. Iowa is the number one producer of pork in the U.S. Companies like Farmland Foods and JBS Swift have meat packing plants in Iowa and employ hundreds of Iowans.

Butter

Butter – We’ve covered butter a time or two before. It is an essential component for the richness of the dish. You could also substitute margarine in place of butter. Margarine can be made from canola, rapeseed, palm, or even soybean oil. Soybeans of course are grown right here in Iowa. These liquid vegetable oils are hydrogenated with water to make them into the more solid margarine that we are familiar with. Depending on the base ingredient they would have different melting temperatures than butter and taste slightly different. It is hard to say which is healthier – butter or margarine – but the key is to eat them in moderation.

Roasted cashews

Cashew nuts – Cashew nuts grow in tropical environments so you won’t likely find this tree in the U.S. Each nut grows out of the bottom of a cashew ‘apple’. These seeds provide proteins, fat and vitamins that contribute to a healthy diet.  Raw, cashews have a toxicity and so it is important to buy roasted nuts unless you know what you are doing to roast them yourself.

Salt and Pepper – Salt is not an agriculture product. It is one of the few minerals that humans mine for consumption. Besides being a great flavor enhancer a small amount is essential in your diet. Black pepper comes from the fruit of a pepper plant species which grows in hot and humid tropical climates. The unripe dried fruit, called peppercorns, are ground into the spice we call pepper. Pepper was one of the spices that early explores traded because of its high value. It came from the spice islands of southeast Asia which also were known for nutmeg, mace and cloves.

Ingredients:Brussel Sprouts with Ham

2 lbs Brussels sprouts
4 slices of thick bacon
2 Tbsp butter
1.5 ounce cashew nuts
Salt and pepper

Instructions:

  1. Rinse and trim Brussels sprouts. Cook in boiling, salted water for 7 minutes or until easily pierced with a knife or fork. Drain and run under cold water to cool and stop the cooking process. Cut each sprout in half.
  2. Cut the bacon into 1/2 inch pieces. Fry bacon in a skillet until crisp. Drain off most of the bacon fat reserving approximately 1 Tbsp.
  3. Add butter and cashew nuts and saute for a couple of minutes until cashew nuts are lightly toasted.
  4. Add Brussels sprouts to the pan and toss. Cook just until the sprouts are warmed through. Salt and pepper to taste and serve.

Enjoy!

– Will

What’s Cooking: Strawberry Banana Smoothies

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In today’s society, many individuals are mindful of living a healthy lifestyle. Articles hit the news every day about healthy eating options and the importance of our food choices. Even the Huffington Post has stated that younger Americans are trending towards more health-conscious eating. A well-balanced and nutritious diet is the foundation of good health. We need to consume a variety of protein, dairy, fruits and vegetables, along with other heart healthy items to maintain health and prevent disease.

Well…I wouldn’t call myself health conscious, but I do try to do little things to be healthier. One way is to start the day with a nutritious breakfast, like a smoothie. I’d like to share the recipe for one of my faves.. and the agriculture story behind its ingredients.

berry-smoothie“Smoothie” is defined by Merriam-Webster dictionary as “a creamy beverage made of fruit blended with juice, milk, or yogurt.”

Yogurt: The word yogurt is Turkish in origin. The discovery of yogurt is thought to be accidental. Early humans stored milk in the intestines of animals. The enzymes that were present in the yoghurtintestines fermented the milk. The milk was thought to last longer and the taste was enjoyed, so they continued making it. Today we make yogurt by pasteurizing the milk, enriching it with powdered milk and then heating it and adding bacteria called yogurt cultures. I prefer fat-free Greek yogurt, which contains three times the protein of regular yogurt without extra calories.

Milk: We’ve all been told that milk is good for us, and there’s a Capturegood reason why. Milk is a natural, nutrient rich, vitamin packed drink that is full with calcium. Milk supports healthy bones and teeth for children and adults. Learn more about milk, from cow to refrigerator, here.

Strawberries: The United States is the world’s largest producer of Strawberrystrawberries, which are primarily grown in the southern and coastal states. Strawberries are the fifth most preferred fruit in the United States, coming behind bananas, apples, watermelons and grapes. Strawberries are packed with vitamins and nutrients like Vitamin C, potassium, fiber and antioxidants. There are many other berries that are great in smoothies too. Check out my “A Very Berry New Year” blog for ideas.

Bananas –Bananas are a creamy, rich fruit that’s good for kids of all ages. 5b620e78c3745dae3a4e6e7156288886They are a great source of vitamins and minerals. Bananas are grown in tropical areas and are produced all year-long. They are the fourth most important crop in developing countries, where they are an important and nutritious starch source. Most of the bananas consumed in the United States come from Central and South Africa. Exported Bananas are harvested in an unripe state. After reaching their destination they are placed in special rooms filled with ethylene gas, which ripens the fruit to maturity.

Strawberry-Banana Fruit Smoothie
• 2 ripe small bananas
• 1 cup frozen unsweetened whole strawberries
• 1   8 ounce carton vanilla low-fat yogurt or Greek fat-free yogurt
• 3/4 cup milk

Directions
1. Peel bananas. Cut bananas into chunks. Place banana chunks, frozen strawberries, yogurt, and milk into blender.
2. Cover blender and blend on high-speed about 1 minute or until mixture is smooth. Turn off blender. Pour drink into 2 glasses.

Enjoy!
-Sheri

Healthy Soil, Healthy Life

Can you believe there is only one month left of the International Year of Soil? 2015 has flown by, but we would be remiss if we didn’t dedicate a blog to this crucial element of life. Soil plays an integral role in human, animal and plant life; we wouldn’t be here without it!healthy soil

Soil, as defined by the Soil Science Society of America, is “the unconsolidated mineral or organic material on the immediate surface of the Earth that serves as a natural medium for the growth of land plants.” Pretty important, right? But more important than just having soil is having healthy soil, or soil that can continue to provide a living ecosystem to sustain plants, animals, and humans. With proper soil management by farmers and other Earth caretakers, the soil we have now can continue to serve its important functions:

  • Provide nutrients for plant growth, such as nitrogen, potassium and phosphorus
  • Absorb and hold rainwater, which improves food security and resilience to droughts and floods
  • Filter and buffer potential pollutants to help keep water sources clean
  • Provide habitat for soil microbes and half of the world’s biodiversity
  • Play a key role in the carbon cycle and mitigating climate change through carbon sequestration
  • Be a foundation for agriculture and the production of food, feed, fiber and fuel

488615811The task of keeping soil healthy is not one that is taken lightly. There are many ways that farmers can work to build and maintain soil health, most of which relate preventing erosion and degradation and improving soil nutrients and structure. Most Iowa farmers work with soils that are very nutrient-rich, have good water holding capacity and a very deep topsoil layer – that’s what makes Iowa such a great place for agriculture! Because the soil is so valuable, farmers choose to use the following practices:

  • Cover crops reduce soil compaction, improve water filtration, and prevent erosion. The plants’ roots break up compaction all while holding soils in place during times the soil would otherwise be fallow, such as late fall, winter, and early spring. Cover crops can also add nutrients like nitrogen to the soil and reduce weed pressure.
  • Crop rotation is a well-known tool that farmers use to increase yields, but also has strong soil health benefits. Transitioning fields from one crop to another each year can improve soil organic matter, reduce soil erosion, and improve soil structure over time.
  • Proper soil nutrient management is a key part of managing soils. Farmers can take soil samples from fields to determine the levels of nutrients, such as nitrogen, potassium and phosphorus, which are needed for optimum plant growth. Using the resulting data, farmers can apply precise amounts of fertilizer to their soils to replenish lost nutrients. Some farmers use liquid manure, which should be applied at soil temperatures of 55 degrees or less, while others apply fertilizers such as anhydrous ammonia, to accomplish this goal. Proper nutrient management is important for supplying nutrients for plant needs without over applying.
  • Minimal or no-tillage practices work for farmers who can plant a new crop directly into the leftover organic matter from the previous year with little to no working, or tillage, of the soil. This works by keeping the soil covered and protected from wind, snow and rain by organic matter residue leftover from the previous crop. Some farmers at this time of year may choose to till only the headlands, or end rows where the farm machinery turns around, to break up soils that may have become compacted from tractors, trucks and combines.

The soil is a very valuable resource, and farmers know it is also a key resource for ensuring future generations will have land to farm and the capability to feed a growing population. Even though the International Year of Soil is almost over, the need for healthy soils is not. Farmers are working every day to maintain and improve the health of the soil we depend on for a healthy planet and a healthy life. What can you do to help?

Kelsey