Joomla Templates Mobile by About Justhost

Glossary - Soil

Beneficial microbes: when discussing soils, beneficial microbes are chiefly microscopic organisms that help build healthy soil. They have a mutually beneficial and supportive relationship with plants and with other organisms that help plants. They may break down nutrients into plant available form, whether in compost or by connecting to plant roots; they can eat or replace disease bearing microbes or fungi in the soil and in the plant. Beneficial microbes can also remove or neutralize toxins from the environment such as petroleum in the ocean, heavy metals, chemical solvents, or uranium in soil. Beneficial soil bacteria have been found to help alleviate anxiety and depression. In permaculture we handle soils so as to increase the number and activity of beneficial soil microbes in our gardens.

Biodiversity: the diverse range and variety of life in a region. In permaculture, we focus on increasing diversity of the beneficial connections between all the elements in the system.

Biomass: the weight or mass produced by plants, animals, or other living things; bio “life”, mass “matter”. Biomass can be considered to be stored energy from organic sources. An example would be cover crop (like rye) used to create organic matter in the field, or crops used to create biofuels or burned to create electricity.

Bioremediation: repairing damage to an ecosystem to the point where it is stable and fertile.

Brown vs green biomass: Brown biomass includes dead leaves, bark and other organic matter that contains mainly carbon and little or no nitrogen. Green organic matter contains enough nitrogen to heat up a pile (the matter provides food for microorganisms that create heat). These heat loving microorganisms facilitate rapid breakdown of organic matter into compost. Examples of items with nitrogen include discarded food, grass, hay, fresh manure.

Clay vs sand: two types of soil. Clay is moist sticky earth that hardens when heated, widely used in making bricks, tiles, and pottery. When you squeeze clay in your hand it will cling to itself, making a ball that sticks together. The grains are smaller than sand. Sand is small loose gritty grains of worn or disintegrated rock with grains larger than clay. You will not be able to make sand into a ball in your hand, unless it is mixed with clay.

Compost - a mixture of decomposed organic material that is stable (resists further decomposition), made with dead plants or plant waste such as leaves or bush and tree trimmings, or animal manure. Compost is the material that is left once these have decomposed. Compost is added to soil to improve its soil structure, like making clay more porous and making it easier for the soil to hold onto water and nutrients. Compost also will make soil disease resistant and make plant nutrients available to plants.

Compost tea: made by steeping compost in water (in a variety of ways). The “tea” is then sprayed or spread on leaves or soil to suppress fungal diseases. Also used as a fertilizer.

Compost vs soil vs mulch: Compost is stable, decomposed organic material teeming with microbial life. Soil is the particles of the Earth’s surface, which contain both inorganic and organic living matter as well as living organisms. Mulch is natural or artificially applied protective covering to the soil. Material used as mulch includes chipped tree prunings, leaves, seedless hay and straw, hugelkultur, etc.

Green manure: Plants or plant material that is grown for the sole purpose of being incorporated with soil to increase organic matter and nutrients. An example would be planting cowpeas that will be chopped down and used as soil mulch. They fix nitrogen from the air into the soil, and thus provide extra nutrients.

Humus: When organic material has broken down into a stable substance that resists further decomposition it is called humus. Humus holds water and nutrients better than inorganic soil, allows beneficial soil life to thrive, stimulates plant growth, helps neutralize pH, and can aid in the prevention of harmful plant pathogens, fungi or bacteria.

Inorganic: not composed of organic matter, not from a life source; examples: rocks, lava, clay, sand.

Leachate: A product or solution formed by leaching, especially a solution containing contaminants picked up through the leaching of soil.

Legume: a certain type of nitrogen fixing plant such as a pea, bean, or acacia.

Loam: High quality soil composed of a mixture of sand, clay, silt, and organic matter.

Mycorrhizae: Symbiotic combination (dual organism) of fungi with the roots of plants. The roots of almost all higher plants exhibit this mutually beneficial relationship, whereby the fungus supplies water and mineral salts to the plant, and the plant supplies carbohydrates to the fungus.

No-till: A method of gardening that does not disturb or till the soil. This helps keep beneficial soil life intact and productive. Tilling and soil disturbance disrupts beneficial soil food webs (see below definition) and kills beneficial soil organisms.

Nitrogen: More than 90% of air is made up of nitrogen but most plants can’t access it in that form. It takes soil microorganisms to convert it to a form that is available to plants.

Nitrogen fixers: Plants that host microorganisms in nodules on their roots, which can take nitrogen from the air and convert it to a form that plants can use. Includes most members of the pea and bean families, clover, plus other species. It’s important to have these species in a balanced system, to ensure that nitrogen remains available in the system.

Organic matter: the partially decomposed remains of soil organisms and plant life including lichens and mosses, grasses and leaves, trees, and all other kinds of vegetative matter. Although it only makes up a small fraction of the soil (normally 5 to 10 percent), organic matter is absolutely essential. It binds together soil particles into porous crumbs or granules which allow air and water to move through the soil. Organic matter also retains moisture (humus holds up to 90 percent of its weight in water), and is able to absorb and store nutrients. Most importantly, organic matter is food for microorganisms and other forms of soil life.

Silt: material consisting of very fine particles intermediate in size between sand and clay. Another definition of silt is any fine sand, clay or silt carried by moving or running water and deposited as a sediment.

Soil: the particles of the Earth’s surface, which contain both inorganic and organic living matter as well as living organisms.

Soil food web: The soil food web is the community of organisms living all or part of their lives in the soil. It describes a complex living system in the soil and how it interacts with the environment, plants, and animals. (Wikepedia) Food webs describe transfer of energies in complex relationships in ecosystems. Much of this transferred energy comes from the sun in the form of photosynthesis, which plants use to turn inorganic compounds into energy-rich, organic compounds that provide food for other organisms.

Soil horizon: A soil horizon is a layer parallel to the soil surface, whose physical characteristics differ from the layers above and beneath. Each soil type has at least one, usually three or four horizons. Horizons are defined in most cases by obvious physical features, chiefly colour and texture. These may be described both in absolute terms (particle size distribution for texture, for instance) and in terms relative to the surrounding material, i.e. ‘coarser’ or ‘sandier’ than the horizons above and below. Water dissolves and removes nutrients as it passes through the soil. (Wikipedia)

Soil life: Soil organisms include the bacteria and fungi, protozoa and nematodes, mites, earthworms and other tiny creatures found in healthy soil. These organisms are essential for plant growth. They help convert organic matter and soil minerals into the vitamins, hormones, disease-suppressing compounds and nutrients that plants need to grow. Their excretions also help to bind soil particles into the small aggregates that make a soil loose and crumbly. As a gardener, you can create the ideal conditions for these soil organisms to do their work. This means providing them with an abundant source of food (the carbohydrates in organic matter), oxygen (present in a well-aerated soil), and water (an adequate but not excessive amount). (

Soil/plant exchanges: Living soils with good structure create many channels and energies capable of exchanging beneficial energies with plants. Electricity flows from soil life to plants and vice versa, changing the chemistry of nutrients to make them more available to plants. Nutrients flow from soil organisms to plants and from plants to organisms in a mutually benefical manner. Live soils have significantly more beneficial interaction and connection with plants than soils without a healthy microbial soil life.

Vermicomposting: using worms to compost material. Worms add their own beneficial bacteria as well as mucus which adds many benefits to soil structure, health and nutrition availability. When compared to normal soil, earthworm castings contain 5 to 11 times more of the major nutrients that plants need to grow.

Worm tea: Worm castings soaked in oxygenated water can be used as a foliar spray for insects or disease, as fertilizer, and as a general tonic for plants. It is full of vitamins, minerals and beneficial microorganisms.

 * * *