Humus Part 2: You Need Fungus, Brother!

When the word Fungus is mentioned, Turfheads often run for the spray rig. Regardless if you want to talk pesticide free turf or not, there has to be a better discussion on Fungi and the resulting role in Humus development by being as key in decompositional shredding as strings on James Hetfield’s guitar.

The first stage in the development of Humus is called Catabolism. It isn’t the warm up act, it is part of a multi-billing. This process should be initiated by fungi and fungal bodies. In their special way, they take the sticks, twigs and debris of various inputs and in the way only they can, they pre-digest materials so that Macro and Meso fauna (Millipedes, Earthworms, etc.) can get to work. Many of those animals lack the digestive enzymes required to get the decomposition process started. In their cool way, fungi make key changes to the soil food system, allowing the breakup of cellulose, chitin and other sticky and twiggy debris forms.

This system process is fueled by fungi that are contained in all plant parts. Like a good tour bus full of roadies and tee shirt guys, plant seeds, leafs and stems are all fungal carriers of the gang that is going to start the process. Nature has this way of getting what it needs and a system that is void of the fungi that support soil life will look for food. Where? From the plant. Now, think about it…what happens if that process starts too early. That’s right. The death band takes over and either the plant is sucked under before it really should be or nature tries to make something happen by calling in the bacterial scabs. See the show must go on. There will be music, but as you are going to see, it can quickly turn ugly.

The liquid portion of the life of the soil, called Soil Plasma becomes a wonderful blend of Proteins, Carbohydrates, Salts, Degraded Organic Compounds and Water. Life. Hot chicks at the after party. No warm mayo sandwiches.

Remember we talked about the powerful bacteria? If they initiate this process bad things happen and instead of Catabolization taking the stage which is who everyone came to hear, the scab band Putrefaction crashes the gig. Putrefaction defined is the decomposition of plant and animal proteins especially by anaerobic microorganisms, described as putrefying bacteria. One of the most common reasons that this imbalance takes place is the presence of excess moisture. Putrefaction tours with its friends Rancidification, Maceration and Fermentation. Putrefaction usually plays songs that result in amines such as putrescine and cadaverine, which have a putrid odor and all kinds of toxic substances are produced like Methane and Formaldehyde and Hydrogen Sulfide.These are not the hot groupie chicks and they are easy to detect because they smell. One of the most common reasons that this imbalance takes place is the presence of excess moisture. And now you know why I’m always harping on having a dry rootzone.

At the end of all this, when it goes right, there is development. When it goes wrong there is a different kind of development. In the show that is supposed to be played, fungal decomposition leads to breaking down food sources for decomposers which eat, digest, pass wastes and sometimes die themselves to be food for the system. It’s neat and clean and it sounds good and smells good and that’s the fresh live smell that we have all committed to our memories as healthy soil. The liquid portion of the life of the soil, called Soil Plasma becomes a wonderful blend of Proteins, Carbohydrates, Salts, Degraded Organic Compounds and Water. Life. Hot chicks at the after party. No warm mayo sandwiches.

Without the fungi, the wrong party begins and when that happens, that soil plasma resembles infection. Toxic compounds, smelly amines, drunken fermented drummers, overdosed earthworms. Skanky groupies. Harmful to soil and deadly to plants. Death. Write your resume. Not a chance that Humus will develop. Death once more. Nothing applied works as it should. Hassled by The Man.

For years, superintendents, green chairmen and others have made fun of me when I am pulling soil samples. As a routine part of my sampling, I use my nose. I smell and often that act is almost as good as a soil test or a pathology report. There is so much information to be had in this kind of observation. That’s why I just sort of chuckle along at being made fun of and take very close notes in my head as to what I smell. It’s fieldwork.

“I’d rather regret trying to do something than not doing something”

–James Hetfield, Metallica

10 Responses to “Humus Part 2: You Need Fungus, Brother!”

  • Whew, I’m glad I’m not the only one who sniffs dirt. I used to do it for fun but now I get paid for it! (Growing up in North Dakota a person develops some strange hobbies.)

  • Dave,

    Doesn’t everyone smell their “dirt?”

  • Chris Rather:

    Taste good too!

  • Dave Wilber:

    Dirt? Gents…have you learned nothing?? Smell Soil. Fine. Dirt? I hope you all have NONE of that.

  • Dave,
    What kind of effect might the fungicides most of us regularly apply to our courses have on desired fungal counts? I have always been curious by this thought. If the regular spraying of fungicides has a negative effect on counts of positive fungi in the soil, than how much could one benefit from reduced fungicide applications? Don’t get me wrong I am not saying it is possible for everyone to reduce or eliminate-I just wonder.

  • Rick Tegtmeier:

    I guess that is why I have worn out a couple of soil probes in my career. I pull samples every day as I drive around and smell them, roll them in my fingers trying to figure out if everything is good and “fresh” smelling as it should be. Nice article.

  • Dave Wilber:


    I think I (we) are going to get to that answer as we go along.
    But, when putrifucation is the most common biological process happening, my experience is denial of fungal development leads to more of the same. While often necessary, perhaps they aren’t always a BMP.

  • bruce nelson:

    Ashes to ashes, dust to dust, organic debris to soil, eh? What happens to those skanky anerobes when the power (H2O) goes out? Do they get drowned out by acoustic aerobes playing the classics?

  • Robert Jenkins:

    When I 1st started in the golf business my mentor told me you have to get down and smell the turf I thought that was a no brainer

  • Matt Strader:


    on a side note I had always heard that dirt is what you get on your clothes and soil is what you grow with…but you can soil your shorts!

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