The Benefits of Microbes in Soil

By Mary H. Dyer | May 23, 2017
Image by tortoon
by Mary H. Dyer
May 23, 2017

Healthy soil is a rich, living environment with millions of busy microbes competing for available water, food and space. Sometimes the microbes eat each other and sometimes they get along just fine. Either way, it’s difficult to grow a viable crop without an active population of microscopic soil dwellers.

Microbes, consisting primarily of bacteria, fungi and a few other tiny organisms, are often thought of as invaders that pose a threat to crops, animal and people. While it’s true that some microbes are bad, most are essential elements of a healthy growing environment.

Here is a quick rundown on a few of the most common microbes found in healthy soil:

  • Bacteria

    are an amazingly diverse group of microscopic, single-celled organisms. They are plentiful and multiply rapidly. In fact, one teaspoon of healthy soil contains at least a million bacteria, and maybe up to a billion.

  • Fungi

    may be primitive plants, but most are the underappreciated good guys of the plant world, working hard to break down plant matter, decompose soil pollutants, discourage pests, fight pathogens and improve uptake of nutrients. A teaspoon of soil usually holds many yards of fine, multi-shaped fungal filaments.

  • Algae

    reside primarily on the surface and upper layer of healthy soil and produce their own food via photosynthesis. These tiny plants hold soil together and help process plant matter.

  • Nematodes

    are microscopic, worm-like organisms. It’s true that some are harmful, but they are greatly outnumbered by good nematodes that eat decomposing plant matter, distribute beneficial fungi and bacteria through the soil, and eat harmful root-feeding nematodes. One square foot of soil contains millions of the little guys.

  • Actinomycetes

    look much like fungi, but they’re actually a unique type of bacteria with a number of important roles in healthy soil, including production of natural antibiotics that detoxify soil and help fight root diseases. If your soil smells rich and earthy, you can be sure that actinomycetes are hard at work.

  • Protozoa

    are single-celled organisms that release critical nutrients like sulfur, phosphorus and nitrogen, thus making them more available to plants. Protozoa are also a good food source for beneficial types of nematodes. How many protozoa in a teaspoon of soil? Thousands!

Microbes work hard and tirelessly to keep soil healthy. Exactly what do those millions of amazing microbes do? For starters, here are a few of their many jobs:

  • Enhance moisture availability and improve water absorption and retention, even in sandy soil.
  • Increase resistance to pests and disease by suppressing harmful pathogens.
  • Reduce erosion and prevent runoff.
  • Prevent compaction by keeping soil loose and arable.
  • Improve soil structure by decomposing organic matter.
  • Retain nutrients around plant roots.

If anyone knows the importance of microbes in the soil, it’s the folks at PittMoss. Their growing media products are not only great for enhancing plant growth but they also provide outstanding air exchange, water availability and distribution of food for microbes, creating an excellent microbial environment. And any gardener knows that great soil means healthy, happy plants.

The above article was sponsored by PittMoss. The information contained in this article may contain ads or advertorial opinions.
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  • stormy
    Comment added May 25, 2017Reply

    Both macro and micro organisms are critical in soils. They are part of this wonderful process we gardeners have to understand.

    Anyone who uses landscape fabric or plastic just is not getting it! Stops the entire process and does not stop weeds!

    A live soil in the garden will always have controls for 'bad' organisms. That is not a worry unless one has used a pesticide to kill animal life in the soil. Dumb.

    The soil from the garden is never to be used in pots! Potting soil in bags is critical. There is actually very very little actual soil in potting soil. All the rest of the media is just for a fluffy medium. Peat moss is a precious commodity and please do not chose potting soil that incorporates peat moss.

    Potting soil is sterilized! If you've ever tried this in your oven or microwave I swear you'll not try it again. Potting soil is cheap! Making it is expensive and takes a lot of experience and although I know how to do this I will always purchase ready made potting soil.

    I will never purchase potting soil with fertilizer or moisture holding gels/sponges! I like to be in control of drainage, watering and knowing exactly what I need to add for fertilizer.

    By the way, fertilizer is NOT nutrients or food! Let's get that very clear. Plants make their own food through photosynthesis and to do that work they need certain chemicals with which to make their own food, converting the light/energy of the sun into carbohydrates. Just a little bit too much and you will kill your plants.

    Using mulches, manures, blood meal, fish emulsion are not meant to be used willy nilly. They all have chemicals that need to be added to the amount of fertilizer or you just might overdo and kill your plants.

    I never add anything but a balanced fertilizer to my potting soil! No mulch, no sand and certainly no rocks at the bottom of my pots. That causes very bad drainage. Actually makes a perched water table where all the small pore spaces of the soil/mix have to become saturated before the water can even begin to drain into the gravel/rock to get out that drain hole!

    Raising the bottom of the pot off the surface of a patio or its saucer using pot 'feet' or pieces of tile truly enhances drainage.

    Water deeply and allow to dry out before watering again is an almost universal truth for growing plants. Germinating seed is a different thing.

    Never plant little baby plants in a huge pot. You have to slowly start with small pots and transplant up to large pots.

    Never take plants from indoors into the sun without acclimatization. They'll fry.

    And viseversa. Going from out doors to indoors needs acclimatization as well.

    It is critical to know how to encourage and feed your micro and macro organisms in your garden soil. They are able to eat ONLY decomposed organic matter. Non decomposed organic matter needs to be decomposed before being useful to the organisms in the soil. Any thing that was once living, now dead will be instantly invaded by decomposers. To 'hurry' this process up, you need to add nitrogen. I hate 'bark' for mulch. If this is all that is available to you, get the finest grind you can find.

    And stop worrying so much about weeds! They are the least of all problems in the garden, I kid you not! Thought I'd throw out some tidbits, I've got my own garden to work on right now!!

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