Particle Size Distribution

To illustrate some of my previous comments about growing media specifications for playing field construction, I drew this to-scale diagram showing the enormous range in particle size that occurs in a soil or media. (Right click the image and open in a new tab to enlarge and see the tiny dot that is the clay.)

Looking at the particle-size diagram, consider how close in size the fine and very fine sand is to silt, compared to the medium and coarse sand. Often times a soil will classify as a sandy loam or a loam and will be chosen for a playing field project with no consideration given to the fact that almost the entire sand portion of the material is made up of fines.

A growing media that resists compaction and degradation and maintains porosity will hold up best against wear and tear. That media includes a good amount of coarse and medium sand.

Mix specifications for turf playing surfaces should always include particle size distribution beyond sand, silt and clay. Specifications vary depending on budget, expectations and intended use, but are important for every project and should be accompanied by a plan for quality control.

Below are two extremely different sets of real-life physical analysis data from Brookside Labs reports. Both of these medias support natural turfgrass on busy playing fields, one successfully and one unsuccessfully.

For more information, see past posts: Growing Medium Specifications, Simplified and Construction: Planning for Success.

Good Physical Analysis


Poor Phys 1


To draw this diagram, I multiplied the sand particles to 500x the smallest size of their class range, and the silt and clay to 500x the largest size in their class range (so we could actually see the clay, drawn at a diameter of 1mm.) Therefore, the coarse sand is represented at its smallest proportional size and would reach twice this diameter at its largest.


Construction: Planning for Success

At DCS we provide consultation on a range of matters related to soil, turfgrass and horticulture. We develop custom recommendations for soil nutrition and analyze physical characteristics of growing media.  We help in the diagnoses of diseases and pests and the remediation of injured areas. We aid in setting and reaching goals for surface firmness, smoothness, safety and ultimate playability. We conduct careful environmental monitoring to help protect waterways and natural habitats.

We often provide advice and expertise in the complete construction of a new park or athletic facility, including in the development of custom specifications, quality control and project oversight. We have ample experience in the field of agronomy and enjoy digging in (often literally) to every step of a project, whether that means crunching numbers in Excel, climbing stockpiles at a mix plant, pulling soil cores from parks, farm fields or greens, writing RFPs or conducting research.

From time to time, however, we find ourselves providing expert witness services and professional opinion in litigation cases. While it is undoubtedly interesting and a change from the usual goings-on here at DCS & Associates, we would much rather be involved in the groundwork and quality control measures that prevent massive legal fees and costly do-overs. Due diligence… we can help with that!

Turfgrass and soils are both so often taken for granted and misunderstood. Massive, fantastic parks and facilities are dreamed up and brought into being, but then the natural turf playing areas fail. Within larger projects that encompass jungle gyms, hardscaping, buildings and other eye-catching infrastructure, soil and turf planning is often put on the backburner.

Half-baked specs are passed around nonchalantly, a growing media that kinda-sorta meets the spec is found and purchased, promises and guarantees are made (or not made) over the telephone and ultimately, the grass dies. The rootzone material purchased is unable to support roots in a high-traffic area, or there isn’t enough sunlight for turf recuperation, or flooding occurs due to poor drainage, or sod isn’t carefully selected to match the soil or site…. And who is at fault? Was the spec followed? Was there a spec in the first place? Was it clear? Were quality control measures in place? Was quality control completed by the appropriate party? Was the person in charge of quality control experienced with growing media specs?

Who done it?

For a large construction project, there are generally several organizations and individuals involved. When something goes wrong, the number of characters that come out of the woodwork and the amount of finger pointing and blame shifting can equate to a melodrama of epic proportions. This can all be avoided with clear and concise contracts, memorandums of understanding, foolproof specifications, and QC to make sure those specs are being met.

When you aim to grow turfgrass under stressed conditions – which are what you’ve got in a busy park, athletic field or golf course – it is so important to develop strong, super-clear growing media specifications that are suited to the environment, early in the construction planning stages. After that, it is crucial to provide everyone involved in construction with the information and education they will need to meet the specs. Clarity and cooperation are vital. Quality control testing is a must. It should be performed regularly and diligently overseen by the person or entity with the greatest vested interest in the success of the project. Material should be tested before it is delivered to the site.  This way, issues can be uncovered, and decisions and adjustments can be made as necessary, before it’s too late to make changes.

A good spec lays out expectations for particle size distribution and behaviours such as hydraulic conductivity and abrasion resistance, for the final growing media blend. A good spec is not a recipe or a ratio of topsoil to sand to compost. Topsoil is sometimes full of sand, and sometimes it has next to no sand at all. Topsoil is generally sourced from nature and can vary throughout a fairly small geographical area. Sands vary drastically depending on the location from which they are sourced. Compost can be produced from a myriad of materials and can offer both pros and cons depending on several factors.

OLYMPUS DIGITAL CAMERA“Sandy Loam” is not an appropriate spec. If a growing media contains a large amount of fine sand, it will classify as a sandy loam, but it won’t perform much better than a silt-loam. Coarse and medium sand content is important, as is aggregate abrasion testing to be sure that the coarse and medium sand won’t break down into fine sand ten years down the road.

There are so many factors to consider when building a natural turf playing surface. A proper site evaluation matched with great specifications and a solid strategy for quality control are super important. Budgeting some time and money for planning and quality control will lead to massive savings in the long run. Cutting corners just isn’t worth the risk.  Plan, plan, plan, plan, plan for success.

But my neighbour’s grass grows just fine in the shade…

The importance of sunlight is fundamental to the growth and survival of turfgrass. It is such old news that we often forget all about it when we’re trying to figure out why the grass won’t grow.  In a busy park, on an athletic field or on a golf green, an ample amount of available sunlight is even more crucial, as turf managers push that turf to grow and recover faster from heavy wear and tear.

Plants require at least seventeen essential nutrients (also called elements). Most of these nutrients are pulled into the plants from the soil, through the roots. If in short supply, most of these nutrients can be provided to the plant by way of a hose and a bag of fertilizer. Oxygen is available through respiration, the same way it is available to us.

Then there is carbon. Carbon makes up about half of the dry weight of a plant – so if you took out all the water, you’d be left with more carbon than any other element. That makes carbon the most “macro” of the macronutrients. And the only way a plant can get the carbon it needs to grow and thrive is to pull carbon out of the air and store it through the process of photosynthesis. Photosynthesis is how we have plants at all and is the reason we’re alive.

Think of plant leaves as solar panels. Light energy is taken in and used to convert atmospheric carbon to useable energy and mass.  More sunlight access = more power = more stored energy and mass.  So when we reduce the size of our leaves, or we limit the amount of light that reaches those leaves, we reduce the plant’s access to the light energy needed to absorb and store carbon; to recover and regenerate.

But, your neighbour’s yard is in the shade! And it’s doing just fine, right?

That may be true, but how often is your neighbour’s yard being trampled by soccer teams, torn by cleats and rolled on by children and furry beasts? How often does your neighbour mow his grass down to one inch… or one-tenth of an inch? Your neighbour’s yard doesn’t have to recover from the abuse that occurs on a busy turf playing surface. It doesn’t have to regenerate itself very quickly, and it is allowed to grow a little longer between meetings with the lawn mower, so it has plenty of leaf surface to access what little sunlight is available.  Therefore, yes it’s doing ok in the shade. Undisturbed and allowed to grow out its sunlight-capturing leaves, it thrives.

Sunlight is a major part of the equation when attempting to grow vigorous and resilient turf. The more wear and tear we put on that turf, the more carbon it’s going to need to recover – to build itself back up. We can provide nitrogen and other fertilizers to help it grow, but to limit exposure to sunlight is to limit the plant’s ability to absorb and store carbon through photosynthesis. And without carbon, there is no turf.

Presentations from the Ontario Turfgrass Symposium

Woodbine track under const

Last week at the Ontario Turfgrass Symposium, Sean Gault of Woodbine Entertainment Group and Dave Smith of DCS & Associates presented their overview of a large project at Woodbine Racetrack: the development of a new natural turf horse-racing surface.  If you missed the presentation, or would like another look at the slides, you can access the slideshow here:

Woodbine Turf Track

In addition to that, Dave also presented on soil testing and interpretation in the Lawn Care room. That presentation is available here:

Soil Testing OTS

If you’re interested in a training workshop or presentation for your organization, please don’t hesitate to reach out to us. Email:

The Consequences of Excess Phosphorus

A healthy aquatic ecosystem is an amazing thing to observe. If watched closely one can see hundreds of small interactions going on constantly between the plants, insects, fish, and other creatures that make up the ecosystem. They exist in a state of relative balance with each other as they each live within their ecological niche and contribute to the community. What is harder to observe (impossible actually) with the eyes alone is how the water chemistry is playing the greatest role of all.

At the chemical level, aquatic ecosystems run on a different nutrient than their terrestrial counterparts. Turfgrass is fertilized with a nitrogen rich compound to create a sustainable ground cover.  A fresh water aquatic environment will largely ignore inputs of nitrogen, instead responding to phosphorus as the factor for plant growth.

Purposely adding phosphorus to a water body to promote plant growth would be considered the height of folly. When phosphorus is introduced to an aquatic system it is immediately taken up by algae. The algae population increases tremendously, creating mighty clouds of unpleasant green muck. Floating colonies of algae group together and can be seen floating on the surface as unsightly green rafts. The algae bloom can’t survive long and all at once begins to die. But the huge blooms don’t have the courtesy to die peacefully and sink to the bottom of the pond. They remain a part of the ecosystem as they decompose.

The microscopic creatures responsible for decomposition require a prodigious amount of oxygen to handle such a large amount of biomass. The huge bloom of algae caused by an over abundance of phosphorus eventually leads to all the oxygen being depleted from the ecosystem as it dies. Many species of decomposing bacteria are perfectly happy to live in an oxygen poor environment, but most aquatic life is uncompromisingly dependent on oxygen. When the algae dies and decomposes, other aquatic life can’t help but follow suit and die as well. The moral of this story is that restricting phosphorus’s entry into a water body can avoid creating an aquatic catastrophe.



Continue reading “The Consequences of Excess Phosphorus”

Soil Science Simplified:  What Is Good Soil?

pexels-photo-296230.jpegMost soil consists primarily of mineral particles derived from rock. The particles range in size from small bits of gravel and large fragments of sand, to microscopic clay particles that look and feel like fine dust, the individual grains indiscernible from one another through the naked eye.

The other solid constituent of soil is organic matter, which consists of raw and decomposing plant and animal material, microbial life and humus: a nutrient-rich compound that is the end result of a long process of digestion and re-digestion by a series of soil microbes.

A productive soil also contains a balanced ratio of air and water, both necessary for the survival and proliferation of plant and microbial life.

The function of soil is to provide a fertile bed and rooting ground to anchor and sustain microbial and plant life – two types of living matter that are dependent on one another. Physically, a soil of good tilth (structure) contains aggregates (particles that are stuck together) which make for good porosity, (space for air and moisture between aggregates) encouraging water and oxygen movement, root growth and moisture retention. Nutritionally, the most productive soils contain an adequate amount of each individual mineral element required for good microbial function and plant growth.

Nutrients are predominantly held in the soil by means of the soil’s “colloidal complex.” A soil colloid is a tiny particle of (usually) negatively charged clay or humus, that is surrounded by positively charged mineral ions which have adsorbed (attached) to the particle’s surface. Tiny clay and humus particles have a huge amount of charged surface area in respect to their overall mass, when compared to larger particles.  Their tiny particle sizes, in combination with other physical characteristics, make clay and humus excellent gatherers of nutrients. (Imagine spreading peanut butter over the crusty surface area of a whole loaf of bread. Then imagine how much more peanut butter you would use to cover every surface if the bread were cut into thin slices.) Colloids are responsible for holding positively charged nutrients (cations) in the soil, (mainly calcium, magnesium and potassium) until the plant root takes up one of these nutrients by exchanging a hydrogen ion for one of the soil’s cations. (More on this at another time.)

Negatively charged elements (anions), namely Nitrogen, Phosphorus and Sulphur are, for the most part, held in the soil solution and kept available for plant uptake within the digestive systems, corpses, and excrement of soil microbes. Billions upon billions of microbes live in the soil. These microbes are living organisms, feeding off of decomposing plant material, and the remains and waste of one another. Soil microbes turn raw plant material and atmospheric gasses into plant-available nutrients, and without their presence, most essential nutrients would escape from the soil’s rootzone before plants could take them up.

Of course, there are exceptions and additions to this basic description of the soil’s methods for retaining nutrients, but I think this provides a decent basis for understanding what’s going on underfoot. (Please walk lightly.)

In the next blog post, I’ll attempt to provide a basic explanation of water and air movement in the soil, and the importance of maintaining a good balance of moisture and air-filled pore space.  Following that, I’ll discuss, in a simplified manner, the method by which plants take up and use nutrients.

The Blogs I Read


The Internet can be a dangerous place for an inquisitive mind. I have to restrain myself sometimes or risk wasting a lot of time chasing information. I’ll go online to look something up and an hour later I’m watching funny cat videos.

That said, the Internet is a rich source of information and inspiration. There are a number of great turf blogs including those by superintendents Jason Haines and Chris Tritabaugh as well as turf scientists Micah Woods and Frank Rossi – the latter actually an audio blog or podcast. I’d invite you to use the comment section or send to me directly any other turf blogs you write or follow and I’ll create a compilation in a future blog posting.

For this article I’d like to share a few blogs that I follow related to my interest in personal and intellectual development with an example article from each.  I hope you find something that is of value to you.

Seth Godin

Seth Godin is an influential business thinker who writes about a broad range of subjects with a focus on self improvement through change, marketing and customer service. He blogs daily but most of his posts are short, thought stimulating articles. Here is a recent example of one of his brief but insightful posts – Beginning is underrated.

James Altucher

James Altucher is one of the more interesting and some would say unusual bloggers out there. He has a background in hedge fund management and you’ll receive a lot of information and offers about investing if you subscribe to his blog but you can sift out many insightful articles written in a uniquely vulnerable yet confident style. His best work pushes the boundaries and challenges conformity – read this for an example – What Happens When You Decide to Change.

Benjamin Hardy

Hardy is a student pursuing a Ph.D. in organization psychology. He writes articles based on current psychological and behavioral science that drill to the very core of what we should be doing to get the most out of our careers and lives. His work is full of practical advice and techniques to embrace positive change. A good example is 30 Behaviors That Will Make You Unstoppable.

Maria Popova

This one is a little different and may not be for everyone. Popova’s blog Brain Pickings is a wide ranging collection of articles on “what matters in the world and why.” I subscribe to the weekly newsletter which arrives in my email early every Sunday morning. Popova provides insightful commentaries on the work of many of the world’s greatest thinkers past and present making their work more accessible for those of us lacking the time and stamina to read as deeply and broadly as we might like. A good introduction to her work is 9 Learnings from 9 Years of Brain Pickings.

It can be overwhelming to save and recall everything of value you come across on the Internet. Keeping a personal journal to make note of ideas and actions is helpful. When I find an article or web page that I want to be able to recall in its entirety, I use Pocket to save it for future reference. It works with your browser or through an app on your smartphone or tablet to allow you to create your own tags so you can organize by subject and easily access for future reading.

Please share in the comments any turf management or other blogs you have created or read regularly. I’ll make a list to share in a future blog posting.

Thanks for reading!

Are You a Professional or an Amateur?

How do you define being a professional? Is it simply that a professional gets paid or is there more to it?

A professional is someone who is fully committed to their craft. Pros don’t wait to be told what to do by others, their inspiration comes from within. They don’t fear failure and criticism but embrace it and use it strategically to hone their skills. Professionals accept in advance that there will be times when they want to quit and do something else but they maintain the discipline and commitment to keep going. Amateurs make excuses, professionals make plans.

Professionals decide what they want to get good at and understand why they are doing it. They develop and commit to a plan, make a schedule and stick to it. They assume a professional mindset. They aren’t trying to be a professional in their chosen field, they are a professional. It permeates their total being and informs their every action.

Are you a professional or an amateur?

Countering Criticism

Criticism is something we can avoid easily by saying nothing, doing nothing, and being nothing.
  – Aristotle

It is inevitable that if you are a creator of any sort, you will encounter criticism. The reality is that we all face criticism in our lives in some form from family, friends, neighbours, employers, clients… even a cat will give you a critical look once in a while, usually around food delivery or attention. What’s the best way to respond to criticism?

Our natural response is usually to go on the defensive with arguments rationalizing our behaviour or work. Perhaps a more effective initial response would be to pause and create the time and space to evaluate criticism in a more detached manner. Is the criticism valid? Can the comments be used in a constructive manner to improve or change?

Direct criticism opens up a pathway of communication. We should be thankful that someone is watching, reading, listening – paying attention to what we are doing. Take advantage of the opportunity to communicate and seek clarification. What can be done to better serve their needs? They may not always respond, but seeking clarity and addressing their concerns shows respect for their perspective and can turn a critic into an ally.

There will be situations when criticism is simply destructive and hurtful. Consider the source. It may arise from a condition of stress, bullying, self doubt or lack of self compassion. Responding in kind is never effective. A compassionate response thanking them for their comments and seeking clarification may help but if the criticism continues or escalates it may be best to just avoid or ignore the source.

The most pervasive criticism comes from our internal, self critic. That voice in our head that raises doubt about our worth, abilities and appearance. Self criticism can be the most difficult to deal with as it is deeply rooted in past experience. However, self criticism also opens a pathway to greater self awareness. Reflect on where critical thoughts originate and what you can do to counter them. This is hard work that takes commitment, time and may benefit from outside professional help, but it is well worth the effort.

Responding to critics of all types is an ongoing challenge but as Aristotle so wisely observed, the only way to avoid criticism is to say, do and be nothing.

Originally published on my personal blog The Rob Log where I post more frequently on a wider range of topics. 

Conference Optimization


As we move into the conference season, I thought it would be valuable to write about how to get the most out of conference attendance. Attending a conference is a significant expense for you or your business so what can you do to optimize the experience?

Advance planning is the first step. Ask yourself what you want to get out of the conference? Are there specific challenges or projects you are facing in the coming year? Review the list of speakers and suppliers and plan to talk to the ones who have information or products you require. Does the conference have concurrent sessions? Read the program and put the schedule and locations into your daily calendar. If the conference has a trade show, make a checklist of the suppliers you want to meet with at the event. If you are planning a large project that requires detailed planning and material procurement, consider scheduling these meetings in advance.

At the conference active participation is the key to getting the most out of the event. Take notes during presentations. Handwritten notes are more effective than using a phone or tablet as you can make diagrams and modify your notes quickly. Draw a line down the middle of the page. On the left side, write down the key points of interest from the presentation. Try to avoid just copying the information from slides but actively focus on what the speaker is saying and extract the information that is most important to you and your operation. On the right side of the page, make your own notes. Jot down ideas that come to mind regarding how you can apply the information you are hearing. If you don’t understand a concept, or need more detailed information, write down questions you can ask the speaker after the presentation. It can be challenging to get up and ask a question at a conference but realize that there are probably other people there who have the same question. If you don’t have the opportunity to ask your questions, try to corner the speaker after the presentation or find their email address or telephone number and contact them as soon as you can.

Conference social events and casual gatherings are both fun and essential networking events. If you are new the industry, or even if you’ve been around for a while, commit to introduce yourself to new people at the event. Seek out industry professionals you may know only by reputation or social media and make a personal connection. Success is a product of the people you surround yourself with so build a network of other successful industry professionals. Sometimes the greatest challenge at conferences is avoiding overindulgence – try to pace yourself so you maintain your professionalism throughout the evening and get some sleep so you can get up and attend the early morning sessions the next day.

In these challenging economic times, many industry professionals do not have the resources to attend conferences, particularly the larger national and international events. If you are able to attend, consider sharing what you learn with others in your region through newsletters, social media or direct communication. Write a summary highlighting your key findings that relate to the challenges faced in your area. This provides a valuable service to others as well as helping you develop your communication skills while reinforcing the new information you gained at the conference.