|
|
|
MailTribune.com
  • The secret life of dirt

  • In our gardens, we tend to focus on the plants because that's what we can see and, in the case of vegetables, eat. But it is the life in the soil that makes it possible for those plants to grow and feed us.
    • email print
  • In our gardens, we tend to focus on the plants because that's what we can see and, in the case of vegetables, eat. But it is the life in the soil that makes it possible for those plants to grow and feed us.
    Let's take an imaginary trip into our garden soil and see who is at home. For example, the weight of all the ants in the world is roughly the same as the weight of 6.8 billion people. Nematodes of various kinds account for about 80 percent of all animals on earth.
    And if you pick up just 1 gram of soil, you will be holding about ten billion individual bacteria, representing more than 6,000 species. Just a cubic inch of soil can contain more than a mile of fungal threads, called mycelia.
    The largest group of microorganisms is the bacteria, accounting for nearly half of the life forms found in the soil. They are located most abundantly around the roots of plants, because they, through the process of decomposing organic materials, make nutrients available for the plants. They help decompose animal tissue as well as plant material.
    Fungi are another important recycler of plant nutrients. In addition to breaking down organic materials, they help protect the plants from being consumed by some of the insects and other organisms that like to eat plant roots for lunch.
    We often think of algae as being present in ponds and streams, but they are also in the soil. Many algae "fix" nitrogen, making it available for plant growth, and contributing to soil-building. Algae, working together with fungi, make trace minerals more available to the plant roots, too.
    So far, we've just talked about microscopic-sized organisms, but larger fellows get in on the act of making healthy soil, too. A variety of worms play an important role in this task, while also recycling nutrients. Earthworms help to improve soil quality by loosening and aerating the soil (all those microorganisms need air, remember), while consuming plant and other organic matter. The product of their digestion, called castings, or worm poop, if you prefer, are rich in nutrients such as calcium, nitrogen, phosphate and potassium.
    Burrowing animals, such as mice, squirrels, rabbits and even those pesky gophers and moles, make their contributions, too. Because they live at least part of the time underground, they are great soil mixers and aerators. Moles, for example, eat only animals, including insects, not plants. The burrowing animals also are important when it comes to mixing oxygen into the soil, and making it easier for water to enter. Try to remember those positive factors as you go to war with them!
    This information is not only interesting, I think, but is another reminder of why it's important to continually add organic matter to our garden soils. We do it to feed all those organisms and build healthy soil. So chop up those leaves and spread them on your garden beds instead of bagging them and setting them at the curb.
    Coming up: Master Gardener Tresa Jarel will explore the idea of creating a community committed to sustainable local living. The class, at the Southern Oregon Research and Extension Center, 569 Hanley Road in Central Point, will run from 7 to 9 p.m. on Wednesday, Nov. 13. Cost is $5. Call 541-776-7371 to register.
    Carol Oneal is a past president of the OSU Jackson County Master Gardeners Association. Email her at diggit1225@gmail.com.
Reader Reaction
      • calendar