Glossaries
Soil
Biologist
Scientist who studies living organisms.
Clay
Tiny rock particle that is smaller than a grain of sand and a silt particle. It can be observed only with an electronic microscope.
Humus
Result of decayed organic matter (plants and animals) in the soil. Humus is an airy substance that retains water well.
Inorganic matter
Non-living matter that has never been living. Inorganic matter includes rocks and minerals. Sand, silt and clay come under this category; they are particles of rocks that have been broken into fragments by the wind and water.
Nutrients
Matter that plants need to grow. They are produced by the decomposition of plants and animals.
Organic matter
Organic matter includes living organisms (e.g. earthworms, insects, microscopic organisms, plants) and dead organisms (e.g. earthworms and other dead organisms, decomposing plants).
Sand
Small rock particle. A grain of sand is larger than a silt particle and a clay particle. It can be observed with the naked eye.
Silt
Tiny rock particle that is smaller than a grain of sand, but larger than a clay particle. It can be observed under a magnifying glass or a microscope.
Texture
Proportion of sand, silt and clay in the soil. Of the three types of grains, sand is the largest. Grains of silt are smaller and grains of clay are even smaller.