Soil Life - Page 2
© Deborah Turton
Fungus are common micro-organisms in soil. Most people think of fungus as only "bad." But that's just not true. Fungus do not use sunlight to make energy. Instead they use chemical reactions to create their energy. They get material for these chemical reactions from dead organic matter, including cellulose, the stuff that makes plants woody. Cellulose is tough stuff, but fungus can break it down making those nutrients available for other organisms. Without fungus, a lot of nutrients would be tied up in undecomposed woody matter.
Nematodes are microscopic "worms." They eat live organic matter. They eat bacteria, algae, fungi, and protozoa. Some eat plant juices by piercing the roots of plants. They even eat each other. They don't eat dead organic matter; therefore, they're not important in the decay of litter. However, they help regulate the numbers of other soil organisms.
Bacteria and protozoa are other great micro-organisms in your soil. Bacteria break down dead organic matter. Certain types fix nitrogen (converting nitrogen from the air into a form plants can use). Protozoa are one celled organisms that feed on bacteria. They release soil nutrients by eating and digesting bacteria. Because they are single celled, they can attack bacteria in small pores that nematodes can't get to. They can also be used as indicators of soil conditions. The more abundant and the more species of protozoa found in your soil, the better the condition of the soil is. Increasing organic fertilizers and decreasing synthetic insecticides will increase the richness of protozoa in the soil.
Macro-organism, or those you can see with your naked eye, are common in and on top of healthy soil. These include worms, snails, slugs, wood lice, beetles, termites, ants, millipedes, and centipedes. Some stay near the surface and eat the litter that drops to the ground. Some, like worms, can be found quite deep (3 m). Some of these soil creatures eat litter, but don't absorb a lot of the material. What comes out is politely called casings and is rich in biological activity. By grinding and chewing the plant litter, these insects increase the surface area available for bacteria and other micro-organisms to break down the material. These macro-organisms also provide food for predators such as birds, toads, lizards, and spiders. These predators in turn will also eat pest insects.
Worms are great for the fertility of soil. Worms traveling through the soil are the delivery trucks of the underworld. They distribute organic matter, bacteria, slime molds, fungus, nematodes, spores, pollen and seeds. When worms move through the soil, they increase the amount of water that can percolate through it. Their casings increase the pH of the soil. Their urine and mucus release nitrogen in to the soil. When they die, their bodies release more nitrogen in to the soil. You definitely want to encourage these creatures to live in your soil.
