Aeration

The exchange of air in the pore spaces of the soil with the air in the atmosphere.

Aerobic

Describes organisms living or occurring only when oxygen is present.

Clay Soil

Soil made up of very fine particles. Holds water and nutrients but does not drain well and can be hard to work.

Fertilizer

A natural or manufactured material added to the soil that supplies one or more of the major nutrients - nitrogen, phosphorus and potassium - to growing plants.

Humus

A dark coloured, stable form of organic matter that remains after most of the plant and animal residues in it have decomposed.

Loam

The best texture for soil to have; it contains a balance of fine clay, medium sized silt and coarse sand particles.

Micronutrient

A nutrient plants need in very small quantities. Micronutrients include copper, chlorine, zinc, iron, manganese, boron, and molybdenum.

Organic

Materials that are derived directly from plants or animals.

Organic Matter

An organic soil substance that contains valuable nutrients.

PH

A measure of how acid or alkaline a substance is. The pH scale ranges from 1.0 to 14.0 with 7.0 indicating neutrality, below 7.0 acidity and above 7.0 alkalinity. Most soils fall in the range from 5 to 8.

Sand Soil

Soil that contains 50%-70% Sand, 0–30% Silt, 15–20% Clay.

Silt

Refers to a soil particle of moderate size – larger than clay but not as large as sand.

Soil Amendment

A material added to the soil to make more productive by improving its structure, drainage, microbial activity, moisture retention or aeration.

Soil Structure

The physical arrangement of soil particles and interconnected pore spaces. The ease with which soil crumbles apart or stays together – friability.

Soil Texture

The measure of percent sand, silt and clay particles in soil. Determines the class name of the soil - Loam, Sandy Loam, Clay.

Top-dress

The action of applying soil material evenly over lawn areas or a bed of flowers.

Tilth

The structure and friability of the soil; the ease of producing a desirable seedbed from the soil.