Glossary

AEROBIC:
occurring in the presence of oxygen. For successful composting, sufficient oxygen should be provided to keep the system aerobic. This ensures that the composting proceeds rapidly and with minimal odor.

AERATION:
bringing about the contact of the compost with air through turning, or ventilating, to allow microbial aerobic metabolism.

ANAEROBIC:
occurring in the absence of oxygen. Anaerobic composting proceeds slowly and is odiferous.

AMBIENT TEMPERATURE:
temperature outside the compost pile.

CARBON-TO-NITROGEN RATIO:
the relative amount of carbon to nitrogen, e.g., a 2:1 ratio means that there is twice as much carbon as nitrogen. Bacteria, like all living organisms, require quite a bit of carbon and comparatively less nitrogen. By providing them with materials that provide these elements in the correct proportion, they thrive, grow, and multiply. Therefore, they can decompose your compost pile at their highest speed. Achieving a carbon-to-nitrogen ratio of about 3:1 is one factor in creating favorable conditions for backyard pile composting.

CARBON:
the basic building block of organic molecules needed for plant and animal life. During decomposition, carbon is released to be reused by plants and animals.

COLD COMPOSTING, COLD PILE:
when less attention is given to providing and maintaining optimum conditions for compost piles, the resulting environment that will attract psychrophilic bacteria, possibly mesophyllic bacteria, but not thermophilic bacteria. As the psychrophilic bacteria work, the compost pile will reach about 55 degrees F. This is the slow method of creating compost from a backyard pile and can take as long as six months to two years to create compost. However, there is little maintenance other than occasionally turning the pile. This type of compost piles requires the least effort.

COMPOST:
completely decayed organic matter. It is dark, odorless, and rich in nutrients.

CONTAMINANT:
unwanted material. Physical contaminants of compost include glass, plastic, and stones, and chemical contaminants include trace heavy metals and toxic compounds.

DECAY, DECOMPOSITION:
the breaking down of organic materials into smaller particles until the original material is no longer recognizable.

INORGANIC:
substances in which carbon-tocarbon bonds are absent. Mineral matter.

HARVESTING:
removing compost from the composting environment for use in the landscape, lawn, or garden.

HOT COMPOSTING, HOT PILE:
optimum conditions for compost piles, with a 3:1 carbonto- nitrogen ratio. Smaller particles of various sizes and textures, moisture, air, and a volume of three cubic feet produce an environment that will attract psychrophilic, mesophyllic, and then thermophilic bacteria. As the thermophilic bacteria work, the compost pile temperature will reach as high as 170 degrees F. This is the fastest method of creating compost from a backyard pile and can take as little as three weeks if the pile is monitored and turned each time the temperature starts to fall.

HUMUS:
a complex aggregate made during the decomposition of plant and animal residues; mainly derivatives of lignin, proteins, and cellulose combined with inorganic soil parts.

MATURE COMPOST:
the stabilized and sanitized product of composting; it has undergone decomposition and is in the process of stabilization. It is characterized as containing readily available forms of plant nutrients; it is low in phytotoxic acids.

METABOLISM:
exchange of matter and energy between an organism and its environment, and the transformation of this matter and energy within the organism.

MICROORGANISM:
microscopic plants and animals. They exist in soil for the purpose of breaking down organic matter into basic mineral elements. They include bacteria, fungi, actinomycetes, algae, protozoa, yeast, germs, ground pearls, and nematodes.

MOISTURE CONTENT:
weight of water in material divided by weight of solids in material.

MULCH:
covering for soil. Mulch should not generally be mixed into the soil; it is not a fertilizer or soil amendment. There are many types of mulch, including partially decomposed compost, bark, wood chips, hay, nutshells, pine needles, and others. The point is to cover bare ground so that topsoil is not washed away, soil temperature is buffered, and weeds are reduced from lack of light. A good organic mulch will also supply nutrients to the earth as it decomposes.

NITROGEN:
a chemical element that makes up 78% of our atmosphere by volume. After nitrogen is released into the soil during the process of decomposition, plants absorb it and use it to further the compost process.

ORGANIC:
belonging to a family of compounds characterized by chains or rings of carbon atoms that are linked to atoms of hydrogen and sometimes oxygen, nitrogen, and other elements.

RECYCLING PROGRAMS:
systems that may be run by private enterprise or local government to gather recyclable materials and remake them into similar or dissimilar products for market. Common products are newspapers, glass, plastic, steel, and aluminum.

SOIL AMENDMENT:
matter, when added to the land, that will make the soil healthier by such means as balancing and adding nutrients, balancing the pH, and encouraging the presence of microorganisms. From a legal standpoint, this is different than "fertilizer" and is not governed by the laws that regulate fertilizers.

STABILITY:
the degree to which the composted material can be stored or used without giving rise to nuisance.

VERMICOMPOSTING, VERMICULTURE:
using red worms to compost food scraps, newspapers, and cardboard, yielding nutrient-rich castings.

WORM CASTINGS:
digested and excreted food products from worms. Castings are five times richer than most fertile soil and are full of helpful microorganisms.

YARD CLIPPINGS:
grass trimmings, leaves, weeds, and shrub and tree prunings six inches or less in diameter from a residence or business.