Rhizosphere describes the plant-root interface (soil or hydro).
The rhizosphere is the area around a plant root that is inhabited by a unique population of microorganisms influenced by the chemicals released from plant roots. Except for carbon fixation by photosynthesis, plants obtain all other elements primarily from soil through roots.
Scientists are just beginning to understand how communications at the rhizosphere with soil organisms and other plant species, affect root exudates and nutrient uptake (Rhizosphere Journal).
The rhizosphere definition has been refined to include three zones which are defined based on their relative proximity to, and thus influence from, the root (See Figure 1). The endorhizosphere includes portions of the cortex and endodermis in which microbes and cations can occupy the “free space” between cells (apoplastic space).
The rhizoplane is the medial zone directly adjacent to the root including the root epidermis and mucilage. The outermost zone is the ectorhizosphere which extends from the rhizoplane out into the bulk soil. As might be expected because of the inherent complexity and diversity of plant root systems the rhizosphere is not a region of definable size or shape, but instead, consists of a gradient in chemical, biological and physical properties which change both radially and longitudinally along the root.
Healthy soils high in organic matter and with a biologically diverse food web support plant health and nutrition better than soils low in organic matter and soil microbial diversity. In addition to supporting vigorous growth of plants better able to tolerate pest damage healthy soils also contain many natural enemies of insect pests, including insect predators, pathogenic fungi, and insect-parasitic nematodes.
The Diverse population of the Organisms in Fish Sh!t are what sets it apart from other products. Fish Sh!t contains the following organisms:
SOIL MICROORGANISMS SUCH AS…
Bacteria are single-celled organisms about 0.5 to 2 mm in length or diameter and they occur in several main shapes. Rod-shaped bacteria are particularly common in soil. Spherical shaped bacteria and spirals are also present. Some species of bacteria form resistant endospores that survive in very severe conditions. The common groups of bacteria are cyanobacteria, eubacteria, gram-negative bacteria, gram-positive bacteria and archaeobacteria.
Common genera of soil bacteria include:
Arthrobacter, Streptomyces, Pseudomonas, Bacillus, Clostridium, Azomonas, Azospirillum, Azotobacter, Beijerinckia, Rhizobium, Bradyrhizobium, Agrobacterium, Nitrosomonas and Nitrobacter.
Single-celled eukaryotes include: diatoms, heliozoans, yeasts (fungi), ciliates, amoebae and dinoflagellates.
Actinobacteria is a phylum of gram-positive bacteria. They can be terrestrial or aquatic. They are of great economic importance to humans because agriculture and forests depend on their contributions to soil systems. In soil, they behave much like fungi, helping to decompose the organic matter of dead organisms so that the molecules can be taken up anew by plants.
In this role the colonies often grow extensive mycelia, like a fungus would, and the name of an important order of the phylum, actinomycetales (the actinomycetes), reflects that they were long believed to be fungi. Some soil actinobacteria (such as frankia) live symbiotically with the plants whose roots pervade the soil, fixing nitrogen for the plants in exchange for access to some of the plant’s saccharides.
There are many shapes and sizes of fungal structures that contain spores, but most are not visible without a microscope.
Some of the major groups of fungi that occur in soil include:
Common Name [Genus] Slime Molds [e.g. Dictylostelium, Physarum]
Zygomycetes [e.g. Mucor, Rhizopus, Glomus]
Ascomycetes [e.g. Claviceps, Saccharomyces]
Basidiomycetes [e.g. Agaricus, Boletus]
Fungi Imperfecti [e.g. Aspergillus, Trichoderma, Penicillium, Rhizoctonia]
Lichens, although not a kingdom, form another important biological component of soils. Lichens are highly specific symbiotic associations between fungi & algae or between fungi & cyanobacteria. Cyanobacteria are bacteria that can fix atmospheric nitrogen, and therefore, they supply nitrogen to the fungal partner in the lichen. A characteristic feature of the association between the two organisms that form a lichen is that the lichen does not resemble either of the partners.
Many types of animals live in soil. Their sizes range from several micrometres to more than a metre. The list includes protozoa (flagellates, amoebae, ciliates), nematodes, mites, collembolans, molluscs, enchytraeid worms, earthworms, millipedes, centipedes, isopods, ants, termites, beetles, dipterous larvae (fly maggots) and spiders.