Written by Mike Hamilton, CCA & President of Turf Dietitian
With an array of designer products and new chemistries on the market, making decisions on what products to apply to turf can be intimidating. We have identified the main reasons for these concerns through years of experience working with golf courses and superintendents. Superintendents want their products to work for the unique conditions and environments and must take into account several factors such as:
- Shrinking budgets
- Plant and soil health
- Regulations
- Product efficiency
Without a doubt, most of our conversations around product selection will go something like this:
Client: “I am using product X. Is it a good product to use?”
Turf Dietitian: “Why are you using the product?”
90% of the time, the client’s answer is: “My salesman convinced me I needed it.”
We get it because we used to do the same as superintendents. Who has the time to research every new product, right? In reality, if a salesman has not carefully analyzed the unique factors on the golf course, such as:
- Water
- Soil
- Physical properties
- Environmental factors
- Plant tissue
He or she is just crossing fingers and hoping for the best. A product may be significant in general, but it may not work specifically for a superintendent’s situation.
PRODUCT COMPARISONS
We are increasingly receiving calls from Superintendents asking, “Which company’s designer products are better?”
We have found that many products we compare are practically identical because they contain the same chemical compounds.
When asked which company’s products are the best, we will research them to find an answer. However, 95% of the time, we recommend using a trusted company to provide excellent service. Occasionally we will discover a new technology from one of our customers or manufacturers.
We never immediately refer the science for two simple reasons: Firstly, it does not mean it will work for all even though it works at one golf course. Secondly, we like to run trials to decide for ourselves based on the results. We set up trials to collect data for 3 to 4 months to identify the product’s efficiency. If we see consistent positive data, we will start recommending the science to our customers who would benefit from the technology.
Most of the confusion concerning product comparison comes from the many chemistries introduced to the market by dozens of companies claiming their product is the best.
The science behind all the products discussed below is sound, but it does not mean a superintendent needs to use all of them. When budgets are tight, it gets hard to determine which of the sciences will be most rewarding for the golf course. Detailed data is the only way to know which products will benefit a club the most.
What type of data is needed?
- Irrigation water
- Physical soil structure
- Soil reserve
- Soil solution
- Nutrient consumption (Plant tissue)
- Physical factors
Upon collecting and interpreting the data for each factor, a logical determination of which sciences to implement will become evident. Alternatively, the easier route is to call Turf Dietitian to do the legwork instead.
Here are the chemistries I will review
- Organic Acids (humic, fulvic, amino)
- Mineral Acids (citric, sulfuric, hydrochloric)
- Plant growth hormones
- Carbon
- Sugar
- Microbial
- Oxygen
Organic Acids
Organic acids are used in the turf industry to chelate and hold nutrients in the root zone longer, build CEC, supply nutrients to the plant root, and add carbon to the soil. The primary organic acids available to the turf industry are fulvic, humic, and amino acids.
Organic Acids (OA) are weak acids that do not entirely break down in the water (slightly insoluble). Most OA form as microbes and plant material decompose. The amount and type of acid produced strongly depends on factors like the type of organic matter, oxygen content, soil structure, water infiltration rates, and product pH.
The higher the pH of an acid, the weaker it is.
Fulvic and Humic Acids
Both fulvic and humic acids function as to be expected. However, fulvic acid has a higher pH, making it the weaker of the two. Fulvic products tend to occupy the rootzone for about two weeks. Humic products, on the other hand, will stay in the rootzone for about one month. Combining the two acids provides a slower to medium rate of release of nutrients to the soil solution. The concern with fulvic and humic is the insoluble fraction of the molecule and where it goes. Insoluble compounds cause soil deterioration.
Not all OA’s have a low pH which can cause future issues by inhabiting the soil for years and causing layering, obstructing water infiltration. Most higher potent organic acids are sold as granulars and commonly used during aerification. Regular use of a granular OA product requires soil testing frequently (a minimum of 4 times per year) and regularly inspecting the entire soil profile. Weaker acids also need frequent monitoring because too much OA in the soil becomes counterproductive.
When are organic acids a better product to use? Use organic acid in sandy soils with low organic levels and CEC but have high-water infiltration. Once soils develop enough organic matter, the rate should exponentially lower. At some point, it is simply not necessary to use organic acids. We would not recommend OA when the organic matter is 2.5 or higher, CEC above 6, or when the saturation index is above 50%.
To determine which company has the best organic acid product, look at the active ingredients for the percentage of acid and the cost per gallon.
Amino Acids
Amino acid, in my opinion, is nature’s perfect acid, despite its complexity.
As we all know, amino acids are building blocks for proteins inside the plant. Amino acids in soil are excellent natural chelators because of their near-neutral pH and low molecular weight (a small molecule that can quickly enter the plant). However, in the soil, they are unstable and quickly leachable. It is also challenging to determine how to use them for plant health efficiently.
When a plant takes in an amino acid chelate, it uses both the amino acid and the nutrient. Some soil product chelating agents (EDTA) are waste material once inside the plant, and the plant needs to use energy to dispose of the waste.
Here is where amino acids get complicated. Amino acids are a perfect balance of acid and primary amino groups in their natural form. The balance gives it a neutral charge. As soil pH changes due to either acids or alkalis inputs, the acid changes from a neutral charge to a positive or negative charge. When we increase the pH of a solution, the amino acid will take on a positive charge. When we decrease the pH of a solution, the amino acid will take on a negative charge.
In the soil, amino acids can rapidly change their charge with any input. Due to the continual change in the soil’s environment, it is difficult to predict the characteristic of the amino compound. Before using amino acids in your program, note this to obtain maximum application efficiency.
I believe every golf course would benefit from using amino acids. However, remember that the science behind using amino acids as a supplement is still relatively new. The science has not advanced enough to know the essential amino acid, what balances are most optimum for plant health, the target ranges for each amino acid, and if there is a level that is counterproductive to plant health.
There are three ways to use amino acids in your programs:
- As a soil product
- As a foliar chelate
- As a straight amino acid blend
I believe that using an amino acid product as a soil amendment is the least effective method due to the instability in the soil. Furthermore, amino acids return to the soil as dead plant material and microbes decompose. The best results come from spraying the leaf with the amino acid. Amino acids are tiny molecules; therefore, they free flow into the plant when applied to the plant tissue. Spraying them on the plant allows for more control over the molecule’s charge.
Cutting the turf at less than 1/2″ tall will not produce enough internal amino acids. For that reason, I believe that every golf course would benefit from the use of amino acids. However, it will take more effort to prepare the product to spray.
We can change the charge of the amino to favor cation or anion uptake by buffering the spray water. To get maximum efficiency from amino acids, we must know the pH of the product applied. If we apply straight amino acids with other nutritional products in the tank, we can adjust the pH of the water to favor either cation or anion uptake. Before we put the product in the plant, w need to adjust the water supply and then pour the product in at the end. Let us say the plant needs potassium and magnesium, and the pH of the product used is 6.8 – buffer the water down to 6, and we will get a better uptake of cations.
If we spray a nutrient chelated with an amino acid, keeping the tank water pH identical to the product sprayed is imperative. Amino acids chelated with an individual nutrient will have the correct charge already. If the pH of the tank water moves in the wrong direction, the nutrient applied may never end up in the plant. If the acid’s charge changes, it will push the nutrient attached off. The free nutrient will connect with another charged molecule that may be too large to go through the cell walls.
When applying a straight amino acid product to supplement the plant deficiency, consider what else needs to be accomplished and adjust the water. If the concern is getting more amino acids into the plant, match the water with the pH of the product.
When comparing two different amino acids side by side, check the number of amino acids in the product. The best product is the one that contains all 20 of the amino acids that the plant needs. Sources of information may show that a number is slightly lower or higher. Always ask the sales rep how many types of aminos are in the product if not on the label. If they do not know, it is simple, do not buy the product until they can answer that question.
Trying to cover all these bases when spraying aminos goes against the Turf Dietitian’s principle of only applying what the plant needs. Unfortunately, without proper scientific measurement of the exact amount of each amino needed in the plant, we have to rely on the manufacturer and the scientist who developed the product. Perhaps in time, scientists will narrow down some target ranges. However, it will take many years before they zero in and completely understand them due to the instability of the aminos and how rapidly they move within the plant.
Mineral Acids
The most popular mineral acids (MA) used in the turf industry are sulfuric, hydrochloric (muriatic), citric, and proprietary mixtures of a combination of acids. Most Superintendents who use MA are using them to reduce soil pH. Nevertheless, MA’s do much more than reduce pH. Reducing ph is probably the least important thing they do.
Mineral acids are powerfully corrosive solutions, with pH that can go down to zero. The lower the pH, the stronger the acid, and the most potent acid wins the pH challenge. The most muscular guy in the gym wins all the competitions but not if he breaks his leg. Overuse and long-term use of MA can lead to severe problems that may break the soil.
As with organic acids, we have to worry about what is not getting solubilized and where it is going. We are seeing some severe soil layering and cementation on drainage systems. So, to reiterate, DO NOT OVER APPLY mineral acids! Monitor the soil structure and inspect the gravel layer on the problematic green once a year. Once these problems occur, the solution to them is usually a bulldozer.
MA also frees up nutrients for plant uptake by solubilizing the insoluble compounds. That may sound contradictory; if a compound is insoluble, how can anything make it soluble? The reality is that there is no such thing as an insoluble compound. Every solid on Earth can be converted into a solution when exposed to strong enough acid or heat for a long enough time.
Some MA deposit insoluble compounds into soil macropores, while others solubilize the compound locked up in the air space. The MA products that can clean clogged air pores and improve water infiltration are the best on the market.
Some new MA chemistries are showing great promise in eliminating clogging and layering problems. However, because they are new, there is long-term uncertainty.
If we look at the same type of acid, there is no difference when comparing products from different distributors. Before introducing an MA acid into a program, research them all. The wrong choice has the potential to cause serious soil structure problems.
Like I have said above, when using MA, monitor the changes frequently.
PLANT GROWTH HORMONES
We know plant growth hormones (PGH) regulate plant growth. Nevertheless, are they good for plant health? If used correctly, I believe PGH can be beneficial to the plant. However, if overused, they can be detrimental to plant health. Please do not go over the label recommendations when using PGH as they are not one of those products where a little is good, so more will be better. More can cause abnormal growth and mutated cell division.
When it comes to PGH, there are a few things that I am unsure of, like knowing an affordable way to check the PGH balance in a plant. I am also unsure if anyone knows a perfect balance with how rapidly they move through the plant. I know that cutting a grass plant at less than ¼” daily will affect the PGH levels.
When looking for a PGH maintenance product, I suggest looking for one with a balanced package of the essential hormones: Cytokinins, Auxins, and Gibberellins. If you are going to use them to fix a temporary challenge, look for the one group of PGH that will be most effective in achieving your goal. Knowing a bit about these hormones can help to select the right product. So, let us break it down:
Auxin
- Bending toward a light source (phototropism).
- Downward root growth in response to gravity (geotropism).
- Flower formation.
Gibberellins
- Stimulate cell division and elongation of leaf and stem
- Seed Germination
- Dormancy
Cytokinins
- Promote cell division in plant roots and shoots.
- Enhance cell growth and differentiation
- Affect and leaf senescence.
Supplement auxins or cytokinin products (mainly in seaweed extracts) to enhance root growth. To move turf laterally or increase the density of the canopy, use a gibberellin product.
CARBON
All living organisms are carbon-based. Carbon atoms adhere with other atoms, which help to structure proteins, fats, and carbohydrates, all of which supply other living organisms with nutrition.
“Carbon” is a nutrient that begins and ends the life cycle of a plant. Plants use carbon dioxide during photosynthesis and convert the energy from the sun into a carbohydrate molecule. Once photosynthesis is completed, the life cycle starts. When a plant or plant material dies and decomposes, carbon dioxide returns to the atmosphere and starts the cycle again.
Practically all sandy or well-drained soils are deficient in carbon because of low levels of organic matter, reduced populations of microbes, clippings removal, and organic matter removal from aerification practices.
Thousands of products exist that must contain carbon, organic acids, sugars, microbial, organic fertilizers, and straight carbon products. When choosing a product, remember this: all carbon is good, but not all carbon products are good.
Many carbon products are derived from humalite and/or leonardite. Both by-products are designated as Humate Products and comprise the same substances: active soluble compounds (Humic and Fulvic Acids), insoluble ash, and heavy metals. Humalite has a much more significant percentage of humic and fulvic than leonardite. Leonardite has a more significant percentage of ash and heavy metals. Another difference is that humalite derives from fresh water, while leonardite derives from saltwater. Naturally, you would want to use the products derived from humalite. However, many of the granular products used in the 20th century originated from leonardite. As proven by our data, overusing leonardite products leaves large deposits of insoluble waste in the soil, causing plugged and layered soil.
There may be some legitimacy behind the minimal use of granular leonardite. However, if you use it, you should monitor the soil structure closely.
Textbooks say the ideal target range for the carbon-nitrogen ratio is 35-40 to 1. However, on sandy greens or other well-drained soil, it is more realistic to expect 20 to 1. We do much testing for C to N ratio, and a large majority of sand-based greens are less than 10 to 1. When soil testing, I recommend your lab test for the C to N ratio to monitor the product efficiency and know when to slow down or stop the applications.
SUGAR (Carbohydrates)
A “carbohydrate” is a biomolecule containing carbon, hydrogen, and oxygen atoms. Carbs are either simple sugars or complex polymers such as starch and cellulose.
Saccharides sugars divide into four chemical groups:
- Monosaccharides
- Disaccharides
- Oligosaccharides
- Polysaccharides
Monosaccharides and disaccharides are simple carbs such as fructose, glucose, sucrose, and lactose. In comparison, oligosaccharides and polysaccharides are complex carbs like starch, glycogen, cellulose, glucose, and glycosidic.
Simple sugars will enhance all organisms in the soil. Therefore if you use them, you’ll need to monitor plant disease. If you get a disease outbreak, stop using the sugar product until the plant overcomes the disease.
Complex sugars consist of several thousands of monosaccharides arranged in chains, so keep in mind that fungi cannot break down complex sugars while bacteria can. The advantage of using complex sugars is that only bacteria get fed, becoming much more potent because they must work hard to consume the food. Think of this as the health impact difference between eating at McDonald’s daily verse eating healthy food regularly.
Monosaccharides’ large particle size causes a portion of the chain to leach through the root zone before being consumed. Sugar waste can cause solid and insoluble compounds (polysaccharides) and layer deep in the soil profile. Therefore, monitor soil structure and water infiltration frequently when using complex sugars.
There are many sugar products on the market. Some are soil products designed to enhance and build microbial populations. Others are chelates for foliar nutrition uptake, and others supplement natural sugars for the plant’s anatomy. I believe every golf course, farm, or landscape operation should feed the soil sugar to expand and enhance microbial populations. The levels of beneficial microbes in the soil strictly depend on the amount of food in the soil. Feed them, and they multiply, starve them, and they die.
In deciding which science to use, research both methods and determine which concept is best for your club’s situation. The jury is still out for us when using newer refined sugar products. We have not seen any plant nutrient levels change from our tissue date. However, we do not test for sugar levels, and I’ve never seen research that shows ideal sugar ranges in turfgrass. That number would fluctuate drastically depending on the height of the cut.
Our concern is overuse. Plant and human anatomy are amazingly similar. What happens to humans when they overeat sugar? They get diabetes. What does too much sugar do to a plant?
My theory is not based only on conjecture: sugars in the plant form in the very early stages of plant life development. Sugar production gets heavily influenced by sunlight, photosynthesis, and leaf density. Before a plant’s first cell develops, there must be a sufficient sugar supply to support the growth. Does the plant need more sugar than it is naturally producing?
In short, we do not know the answer yet, but we are working on it. If you use straight sugar and are witnessing a consistently healthier plant, then, by all means, keep using it and let us know what benefits you see. Inputs are the most valuable part of our success.
Microbes
My knowledge of microbes is relatively strong. I sold one of the original “Bug in a Jug” products in the mid-’90s. Most of the early products had a handful of species common to practically every soil in the world. The secret of the early products was the food used to increase the native populations. The current-day microbial products have hundreds of species of indigenous and non-indigenous species. They are designed to introduce an entire community of organisms that work together to achieve maximum soil health, but do they work? My opinion is absolutely yes, but it may take time to reap the benefits.
Can the theory be proven? Yes, it can, but the expense associated with the testing procedure to identify and count hundreds of species is prohibitive for most golf courses. Because testing is impractical, you must rely on results and soil data to prove that the products are viable. Regrettably, it can take a few years before the colony of microbes in the product begins to dominate the population.
It is world war 3 in the soil every minute of every day. When you add non-indigenous species into an indigenous species, they have to fight to survive. In the beginning, they face impractical odds of survival. Many organisms live 20 minutes but produce 20,000 offspring in that time. If only two organisms endure, you have started the community. In war, if you reinforce the troops every 20 minutes, you will eventually win that war.
My belief is stronger than most because I’ve spent time with microbiologists that have developed products and studied the task of each species. I’ve also watched root colonization and predator attacks under a microscope. That is some cool stuff!
Many manufacturers claim their products’ efficacy, including disease suppression, nematode suppression, nutrient mineralization, improvement in soil texture and structure, and improvement in plant health.
If you are using a diverse community of microbial organisms, you will eventually experience all those things. Other than visually witnessing the suppression, there is no way to prove many of those claims. However, I could frequently prove a reduction in organic matter and improvement in the saturation index after six months.
If you’re a believer in microbial products, you should only consider the number of microbes in the mixture. Very few companies will show you the names of all the species in the mix because they all have their own secret brew. However, you can trust that if a product has large communities of bacteria, much research went into creating it.
It is possible that, eventually, every grower will have their own unique blend of organisms that are ideal for their property. That won’t happen in my life, but perhaps some of the younger generations will see that theory come true.
OXYGEN
I don’t have to give anyone an explanation of oxygen’s impact on life; you’re reminded about 15 times every minute. But, are oxygen products effective? Yes, if you are using the right chemistry.
Can you have too much oxygen in the soil? Perhaps. Think about brand new USGA greens and the challenges of holding water and nutrients in those conditions. I don’t believe you should use oxygen products until the physical condition of the greens naturally worsens, but I would much rather be on the side of caution when it comes to oxygen.
Unless you’re supplying oxygen mechanically, the only option to get oxygen in the soil is using hydrogen peroxide (HP). The original HP products work great, but for only about 2 minutes. HP is highly unstable and will volatilize immediately into the atmosphere when sprayed on the surface.
The newer generation of HP products is chemically enhanced to stabilize them to provide a controlled release of oxygen. These products are much more effective than the old HP products and show great promise. The secret of efficiency with the stabilized products is to water them down to the root zone and apply them as frequently as possible.
SUMMARY
There are many new technologies used and introduced into the industry. These technologies have created much confusion for superintendents, as it is now difficult to discern which solution is best for their programs.
How do you determine which products fit your challenges? Educate yourself on the science behind the products. Most of the products in each category are identical or very similar, so buy from the companies you trust the most.
Finally, test the soil and plant tissue to conclude the efficiency of the products, and do not over-apply just because you can, because overapplying could cause more harm than good.
