Written by Mike Hamilton, CCA, Turf Dietitian, Inc
Now that Turf Dietitian is testing the levels of simple carbohydrates in plants with our plant tissue equipment, we must learn as much as possible about their significance in the plant and soil and share the knowledge with you.
As humanity has evolved since life started on Earth, we would completely understand how plants live. We know many times more than we knew 100 years ago, but there is still so much to learn and understand. We will need more time to live and understand plant anatomy completely.
As humanity has evolved since life started on Earth, we would completely understand how plants live. We know many times more than we knew 100 years ago, but there is still so much to learn and understand. We will need more time to live and understand plant anatomy completely.
Here are some basics: There would be no life on Earth if it were not for plants. No one knows what came first, seeds or plants. Although there may be some strong opinions on this, not one person on Earth can be 100% sure.
The more we learn about a plant’s metabolism, the more we realize just how complex every function is. By the time the plant finishes its last function and spits out proteins, it has gone through 10s of thousands of chemical and biological reactions.
This article will only discuss one part of this incredibly complex process: carbohydrates.
- How do they form?
- What is their function in the plant?
- What is the relationship between them and microbes?
- How can growers use them to inhibit plant health?
How do carbohydrates form in plants? Plants use the Sun’s energy (Photosynthesis) to change water and carbon dioxide into glucose, a sugar.
Amazingly, this simple-looking equation above is responsible for all life on Earth. Yet, everything between the Sun shining and the plant producing oxygen and protein is so complex that humanity only understands a fraction of these natural functions. It takes tremendous energy for a plant to grow from seed to organic waste in the soil after it dies.
That is the basis of what you need to know.
So, let’s dig deeper to learn a bit more. Even though this article is eight pages of mind-numbing text, it just scratches the surface of what scientists know about the carbohydrate process in plants and soil.
Golf course superintendents are in the business of providing manicured turfgrass surfaces on which humans can play a game. That sounds so easy! Many golfers believe what you do is easy, but you and I know many factors and specialized skills are involved in the end process.
You are actually utilizing your specialized superior skills to provide the ideal environment for the plants to capture the light energy from the Sun. The more that big ball of fire in the sky shines its light on the plants, the healthier the plants will be, which equates to superior playing surfaces.
Here is another reality: the plants have no idea what you are trying to do. No matter where a plant is and what we are growing it for, it is only trying to achieve its biological purpose.
So, what is a plant’s biological purpose? To capture the Sun’s energy and tum it into chemical energy to produce oxygen and proteins. That sounds so easy! Just like your job, there are thousands of factors involved in this process. The more energy the plant produces, the more life is being sustained from that energy production. Not only plant life but microbial and even human life.
Warning: These next couple of paragraphs are strictly my theory. I do not think there is enough research to prove or disprove what I am saying. But after nearly 50 years of conversations with microbiologists and agronomists, I believe many share these theories.
A superintendent can cut or trim trees to increase the sunlight on the leaf blades, but even in full Sun, manicured turf gets only a small fraction of light. Why? Cutting the turf at extremely low heights removed 99 percent of the plant’s ability to absorb the light rays from the Sun.
Here is what interests me. A turfgrass plant being cut at 1110th of an inch will only have the energy to produce a negligible amount of sugar. However, that negligible amount of sugar is the exact amount that the tiny little plant needs to function and stay alive. Adding more sugar to the plant is only beneficial if it is linked to something a plant needs, like a nutrient.
Is the plant stressed being cut at 1110th of an inch? OH, HELL YES! But does adding sugar to the plant leaf or solubilizing it into a solution to be taken into the roots help the plant to be less stressed? Unfortunately, no. There is only so much sugar a plant can hold, and roots cannot take up sugar water.
So why are Turf Dietitians and practically every agronomist in the wor1d so persuaded to recommend frequent applications of sugar? It is to feed the microbes in the soil! Feed the guys who feed and protect the plant. Feeding microbes provides the plant with a balanced diet and diminishes all forms of abiotic and biotic stress on the plant.
Now that Turf Dietitian has all the companies selling sugar directly into the plant ready to tar and feather us let us explain more. The complex sugar compounds in your products are very beneficial, but not in the way one may think.
We found very few scientific articles supporting the theory that adding sugars designed to go into the plant benefited plant health. At the same time, we saw many research articles supporting adding sugars to the soil to raise the levels and diversity of microbial communities. The benefits ranged from reducing or eliminating plant stress to providing the plant with a balanced nutritional diet and reducing the amount of carbon dioxide released into the atmosphere, to name a few.
Turf Dietitian has talked to several superintendents who use sugar products designed to affect the transpiration of water in and out of the plant. Many see value in this soluble application. We do not doubt that the net result of using those products is beneficial to the plant. But believe the benefits seen are more due to the product being washed off the leaf or being made available once the leaf decomposes in the soil. However, this is just a hypothesis of Turf Dietitian.
You may be asking why we are testing for individual sugars inside the plant because they hold the key to raising a healthy, diverse community of microbes. Its biological purpose is to keep the plant healthy.
Even though most of us believe that the sum of man’s knowledge has allowed us to know everything there is to see, we still have a long way to go to understand the complexity of this interaction between microbes and plants.
Adding sugars to the plant to balance the sugars within that plant may have some validity. However, much research is needed to determine what that proper balance is and how one gets the sugars deep enough into the plant to affect and change the balance.
Most of the research we read concluded that plants sprayed with soluble sugar products saw only a slight decrease in pathogen activity on the crops being tested. This is more likely a function of increased microbes and not a plant response.
Because Turf Dietitian has the time to do that research, we will focus on the proven scientific knowledge of feeding sugars to microbes in the soil. Do not get us wrong; there is still much to learn about feeding soil. Also, the answers we have today may be disproven and obsolete in a few years. However, as of now, frequently supplying microbes with food is the best and least expensive way to ensure healthy plants.
Everything we must do to manage manicured turfgrass goes against nature. Turf growers harvest the crop frequently, irrigate the plant with poor-quality water, and stress the plant to the point that chemicals and synthetic fertilizers become mandatory. Many grow their turf on low organic sandy soils; sometimes, it grows in an environment suitable for turf. Hence, the saying you rarely see grass in a natural forest, and you rarely see trees on a grass prairie. In other words, it is a miracle what turf growers do daily to keep their greens alive for just one more day. Focusing on improving the soil helps compensate for all the obstacles you must encounter to make the golfer happy.
If Turf Dietitian were to talk to 1,000 superintendents, we would hear 1,000 different ways to manage a golf course. However, there would only be a handful of philosophies:
- Good cultural practices with minimal
- Good cultural practices with mostly chemical and synthetic fertilizer
- Good cultural practices with mostly natural pest control and organic fertilizer
- Good cultural practices with a combination of all
- Water and mow with no inputs
Carbohydrates are an essential compound of all organic life on this planet. Both plants and animals use carbohydrates as a primary source of energy, which keeps the plant functioning at the most basic level. Carbohydrates also fulfill other needs by helping the plant synthesize many complex carbon compounds.
Plants use simple sugars signal chains like fructose, glucose, and lactose to perform many tasks within the plant. These simple sugars break down quickly, providing a quick source of energy for the plant. The quick breakdown of these sugars releases carbon atoms used in every biochemical process in the plant and organic process in the soil.
Polysaccharides fulfill other functions in organic life, one of which is to serve as antigens, substances that trigger the creation of antibodies for the immune system.
Long complex chains of many simple single-chain sugars are stored in the plant as starch. Starch becomes a usable reserve for plants when photosynthesis is reduced by cloud cover and at night without photosynthesis. Other complex sugars, known as polysaccharides, chitin, pectin, and cellulose, give a steady supply of energy, while simpler sugars supply a quicker burst of energy before dissolving. Complex sugars are responsible for more compound plant functions, such as building cellular structures.
Cellulose is a polysaccharide that creates a solid wall around the plant cells, giving the plant its structure. Since plants have no skeleton or other weight-bearing form, these cell walls provide the framework by which plants can stand and extend.
Pectin is a polysaccharide that acts as an adhesive to hold plant cells together and prevent water seepage between individual cells. It is a natural component responsible for cell hydration.
Chitin is a polysaccharide that promotes plant growth and aids a plant’s resistance against biotic and abiotic stress and activating symbiotic signaling between plants and beneficial microorganisms. Plant cells high in chitin have the ability to protect the plant from freezing conditions, as well as protect the plant from leaf pathogens and chewing insects.
Simple sugars play a more significant role in respiration than complex sugars. The plant’s phloem transports the dissolved sugars from the leaves and takes them to various storage sites throughout the plants, like roots or tubers. The phloem offloads its sugary plant food to the roots and across cell membranes through a process known as active transport. As much as 80 percent of the sugars created through photosynthesis are delivered to the plant’s roots. These sugars and compounds linked to the sugars are then pushed out into the soil to become food and energy for the microbiome. It is like ringing the dinner bell to all hungry microbes.
Sugars are transported through the plant through the function of transpiration. Water that is absorbed through the plant’s roots is mixed with the sugars within the plant and then delivered throughout the plant to provide energy to every cell in a plant’s body. Excess water exits through a plant’s stomata, and the excess water evaporates while the sugar dries on the outer surface of the plant leaf. This exposed sugar attracts airborne microbes and insects. Many insects that are attracted, like bees and herbivores, are responsible for seed germination and spreading.
Translocation of sugars (photo assimilates) in plants.
Plant health, sugar content, and carbon content can be checked with a simple tool called a Brix meter. However, the Brix meter measures not only total sugars but also includes amino acids, lipids, and other carbon-produced molecules. Although the Brix meter can be a valuable tool to measure plant health, it does not measure individual sugars and their levels in the plant. Turf Dietitian hopes to do this with our plant tissue testing data.
Plants with higher sugar levels show greater resistance to disease and insect attack. However, current research shows that disease resistance is more a function of increased microbial populations than natural plant immunity.
As photosynthesis increases, more significant amounts of plant sugars are transferred out through the roots to feed soil microbes, making minerals available to the plant. This factor alone illuminates why turf growers are forced to use large amounts of chemicals and fertilizers for their plants to survive. A plant not allowed to grow to its natural height will not produce enough microbial food for its caretakers. Therefore, turf growers substitute chemicals and fertilizers to achieve plant health.
Like always, we are sure you are tired of Turf Dietitian talking about microbes, but you can only really speak about carbohydrates if you talk about microbes. Remember the thousands of tasks microbes do in the soil, and adding carbohydrates enhances practically every microbial function.
One 24-hour period produces many generations of microbial communities. Why is this significant? Photosynthesis activity creates a temporary feast for soil microbes, but unfortunately, the Sun only shines for about 12 hours.
Because there can be billions of microbes in a cup of soil, the sugars produced by photosynthesis are depleted quickly. This depletion of sugar reduces microbial populations. Fortunately, the plant has already figured out how to compensate for the lack of sunlight; it stores carbohydrates in the form of starch. However, at night respiration is slower and not as much sugar is being pushed out of the plant, and microbial levels can quickly decline before the Sun rises. Many things can go wrong in just those few hours. Supplying supplemental sugar can help to bridge this gap.
Here is another interesting fact about carbohydrates. Soil organic matter contains over 50 percent carbon. Globally, soil contains more carbon than plants and the atmosphere combined. Due to plowing soil on farms and erosion from fields left void of vegetation between plantings, much of the topsoil in the world is depleted of carbon. Low-carbon soils release more carbon dioxide, which can accelerate climate change. Refurbishing carbon in the soil will increase the levels and enhance the soil’s natural ability to sequester carbon dioxide.
For many years, we believed that decaying plants replenished a large portion of the carbon removed from the soil. However, recent studies have shown that most of the sustainable carbon in the soil comes mostly from dead microbial bodies.
Microbes consume simple and complex sugars and convert them into many compound molecules found in soil. The carbon in the sugars and other compounds is significant in enhancing soil microbes quickly and efficiently. This enhancement of the soil microbes, especially digestors and plant stress reducers, turns dead plant materials into soil organic matter quickly and protects the plant from pathogens and parasitic nematodes.
Chemical interactions are constantly taking place between plants and microbes. It is how they communicate. Plants send chemical signals and release molecular compounds like sugar, amino acids, and proteins through the root to exude and attract specific microbes to address a plant’s needs.
We do not have a universal translator like in Star Trek, so we are just theorizing about how sophisticated this brilliant communication is. Our theory is that anything as complex as a plant can effectively communicate at a much higher level than scientists have discovered. Since carbohydrates are involved in every process in the plant and soil, they play a significant role in plant and microbial communications.
Sugars will feed every organism on the plant leaf or in the soil if the soil has sufficient oxygen and the plant is healthy. The more sugar in the soil, the larger the microbial community will be and the healthier the plants will be.
However, turf green growers are constantly stressing the plant. The plants are grown on sandy soils that are naturally low in microbes and high in oxygen. The plants are cut so low that they are not producing enough sugar to feed a single amoeba. Also, the greens often grow in reduced sunlight and have other abiotic stressors. So, how do you get enough carbon and sugar into the soil to reduce the stress on the plant and yourself? Could you work with us at Turf Dietitian? We work with qualified microbiologists who analyze the soil’s DNA. With their help, we build microbial and soil food programs that plug all the weaknesses in your specific soil to make your soil healthier over time.
DNA testing is a newer science. It allows microbiologists to learn more about soil health and how to fix it acceleratedly. What once took a microbiologist a lifetime to learn is now achieved in a few years.
Building efficient and effective microbial programs will be different for every crop. Mycorrhizal fungi and higher plant health microbes feed mainly on polysaccharides and other complex carbohydrates. Short-lived beneficial bacteria, scavenger microbes, pathogens, anaerobic microbes, and parasitic nematodes will rarely exhaust the energy needed to break down complex sugars. They thrive on simple sugars. Higher-level microbes also feed on simple sugars, but feeding simple sugars alone can be dangerous due to the predator’s population growing at an equal rate. How do you compensate and ensure you apply the suitable types and amounts of sugars? Take a DNA soil sample and have us prescribe a balanced food source for your unique soil biology.
Also, every type of plant and maybe even every turf species will have different requirements. In general, sandy soil typically has higher populations of bacteria than fungi. Recent research has shown that grasses, annuals, succulents, and short-lived plants prefer slightly higher bacteria levels to fungi. Fems and mushrooms prefer high fungi ratios to bacteria, long-lived plant specimens, and forest plants, like large trees.
If you made it this far, thank you. Turfgrass cut at less than 2 inches cannot produce enough sugar to feed the microbes that keep it alive. Therefore, using artificial means to keep the plant alive becomes necessary. These artificial means continue to diminish the natural soil biology. However, by adding natural plant-produced sugars, you can improve soil biology and reduce the usage of chemicals and synthetic fertilizers. Because the practices that provide superior playing conditions are so stressful to the turf, turf growers will likely always need to use some artificial stimulus to grow the turf. However, any reduction in the use of chemicals and synthetic fertilizers is a positive response from turf growers and a benefit to all living organisms on the Earth.
On another note, do not confuse synthetic fertilizers with liquid composted fertilizers. What are liquid composted fertilizers? They are nutrients that are chelated with carbon carriers like sugar, amino acids, humic, or other organic carbon compounds.
If Turf Dietitian has cultivated your interest in learning more about carbohydrates, or if you would like to learn how to incorporate complex sugars and other organic carbon products into your soil programs, call Turf Dietitian. We would love to share our knowledge with you.
With Much Respect,
Mike Hamilton, CCA
239-707-9974
Turf Dietitian
The Healthy Turf Experts
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