SOIL BACTERIAWhat bacteria lack in size, they make up in numbers. They are tiny, one-celled organisms. A teaspoon of productive soil generally contains between 100 million and 1 billion bacteria.
Has four functional groups. 2. A second group are the mutualists that form partnerships with plants. The most well-known of these are the nitrogen-fixing bacteria. 3. The third group is the pathogens. 4. A fourth group, called lithotrophs(literally meaning rock eaters) or chemoautotrophs(which are able to synthesize all of the organic compounds they need from inorganic raw materials in the absence of sunlight.), obtains its energy from compounds of nitrogen, sulfur, iron or hydrogen instead of from carbon compounds.
Functions
Important Bacteria Nitrifying change ammonium to nitrite then to nitrate – a preferred form of nitrogen for grasses and most row crops. Nitrate is leached more easily from the soil, so some farmers use nitrification inhibitors to reduce the activity of one type of nitrifying(scavenging potentially toxic nitrogen compounds from their surroundings, including: ammonia and nitrite). Nitrifying it are suppressed in forest soils, so that most of the nitrogen remains as ammonium. Denitrifying convert nitrate to nitrogen (N2) or nitrous oxide (N2O) gas. Denitrifiers are anaerobic, meaning they are active where oxygen is absent, such as in saturated soils or inside soil aggregates. Actinomycetes are a large group of bacteria that grow as hyphae like fungi . They are responsible for the characteristically “earthy” smell of freshly turned, healthy soil. Actinomycetes decompose a wide array of hard-to-decompose compounds and are active at high pH levels. Fungi are more important in degrading these compounds at low pH. A number of antibiotics are produced by actinomycetes such as Streptomyces.
They are found where?
One celled organisms that encourage plant growth Certain strains of the soil bacteria have anti-fungal activity that inhibits some plant pathogens(A disease-causing organism). Those strains can increase plant growth in several ways. They may produce a compound that inhibits the growth of pathogens or reduces invasion of the plant by a pathogen. They may also produce growth factors that directly increase plant growth. The plant growth-enhancing organism occur naturally in soils, but may not be in high enough numbers to have a great effect. Soon, gardners may be able to coat seeds with this anti-fungal to ensure that the bacteria reduce pathogens around the seed and root of the crop. Return from one celled organisms ( bacteria ) page to Organic Fertilizers
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