Soils
and soil ammendments
This page is intended to provide information primarily about the physical composition and structure of soils, pH and salinity.
Mineral nutrients and fertilisers are covered more extensively on Plant nutrition and mulches and mulching practice are covered on Mulches. Other related subjects include Compost and Composting and Worms.
However, soil fertility, soil structure and soil chemistry can't be separated completely because many fertilisers and mulches contribute both plant nutrients and add organic matter. On the other hand, some materials added to correct pH problems can also contribute plant nurients. Furthermore, issues like pH and aeration can have an effect on the availablility and uptake of plant nutrients present in the soil.
As the basics are covered extensively in other gardening publications, the aim here will be to concentrate on information from Qld, covering issues relevant to Qld, or other potentially useful information that may be hard to find otherwise.
More about soils and growing media for containers here: Potting Mixes
Note that commercial products, regulations, plants and soil types vary from place to place, so some information in links may not apply where you live.
Links
Queensland Soil Types
Look for regional gardening and environmental groups (who might be able to supply information on local soils) on the Regional pages.
General Information
Understanding soils A number of factsheets can be downloaded from this page. Queensland Dept Environment & Resource Management
What is Soil? Basic overview. Department of Primary Industries Victoria
Soil biology basics factsheets on a variety of topics available from this page. NSW department of Primary Industries
Water penetration and retention
Does gypsum improve clay soils?
There's a widespread misconception, even amongst horticulture professionals, that gypsum can improve the structure of every clay soil. Check out the following links:
pH
Soil pH Colorado State University Extension
Lawn and Tree Myths (do pines make soil acidic?) Washington State University Clark County Extension
Cation exchange capacity
Organic Matter, Carbon
Salinity
Soil testing
Other
The Myth of Soil Amendments Part II Will adding sand improve the texture of a clay soil? Washington State University (PDF)
Manufacturers and distributors of soil conditioners and amendments available in Qld are invited to advertise on this page. For example: composts including treated wastes, wetting agents, pH adjustment, water storage additives (granules, gels), additives for drainage and porosity, flocculation agents. More information about advertising.
More about mulches and mulching practice here: Mulches | 
