| Actinomycetes |
Microorganisms between bacteria
and fungi. They produce
characteristic branched mycelium and are responsible for the earthy smell of
compost. |
| Activator |
an
addition to the compost pile containing nitrogen or a source of sugars. Its purpose is to increase microbial
activity by providing food. |
| Aerobic |
occuring in the presence of
oxygen |
| Aggregates |
The structures or clumps formed
when soil minerals and organic matter are bound together wuth the help of
organic molecules, plant roots, fungi and clays |
| Anaerobes |
bacteria which do not need
oxygen |
| Auxin |
a substance found in places such
as plant sprouts (especially willows) and human urine which stimulates growth
in plant tissues promoting root formation.
The basis of rooting powders. |
| Available
nutrient |
the form of a nutrient that the
plant is able to use, eg ammonium or nitrate as opposed to free nitrogen or
nitrogen in an organic compound |
| Bacteria |
Single-celled microorganisms
that break down organic materials in the early stages of composting. . The
three types of bacteria are psychrophilic, mesophyllic, and thermophilic. It
is the latter two that generate the heat associated with hot composting |
| Browns |
Carbon rich materials which
provide bulk in the compost pile |
| Buffering |
The slowdown or inhibition of
changes in availability of nutrients due to varying pH. A buffer tends to neutralize both acids
and alkalis through the exchange of Hydrogen ions. |
| C:N
ratio |
The relative amount of total
carbon to total nitrogen in a compostable material |
| CAC |
Cation Exchange Capacity:The
amount of negative charge on humus and clay particles that allows them to
hold on to positively charged ions (cations) |
| Clay |
Soil with extememly fine
particles, less than 0.002mm |
| Compost |
organic material that has been
well decomposed by organisms under conditions of good aeration. |
| Fertility |
the condition of the soil which
best promotes growth |
| Fertilizer |
unless qualified with
"natural" or "organic", this refers to some combination
of nitrogen, phosphorus and potassium added to the soil to promote growth. |
| Friable |
crumbly, falls apart when lifted |
| Greens |
Nitrogen -rich organic
matter.Any matter coming from an animal source, most specifically manures,
Also green plant material, including leaves and small branches cut while
green. Dried grass clippings are
still green. |
| Humus |
The very well decomposed part of
the soil organic matter, made up of long chains of carbon compounds,
including humic and fulvic acids. Has a high CAC |
| Leach |
To
remove soluble minerals from the soil by the action of a percolating liquid,
particularly rainwater |
| Loam |
A mixture of soil types, usually
with organic material incorporated |
| Macro-organisms |
Visible creatures which live in
or on the soil:worms, spiders, mites, daddy longlegs, centipedes, millipedes,
all the insects, sow bugs and pill bugs, slugs and snails |
| Micro-organisms |
bacteria, fungi, protozoa,
actinomycetes and nematodes. Too
small to see with the naked eye |
| Porosity |
the openess of the soil and the
amount of air which can percolate through it. |
| Sand |
The coarsest form of soil with
particles, visible to the human eye |
| Silt |
Soil with fine particles, 0.06mm
or less |
| Tilth |
The physical condition or
structure of the soil as it influences plant growth. A soil with good tilth is very porous and
allows rainfall to infiltrate easily, permits roots to grow without
obstruction, and is easy to work. In
other words, how easily the soil can be tilled or otherwise worked |
Compost International 
