Zeolite in the Soil
Natural zeolite has an open box work crystal structure which is occupied by cations and water molecules. These ions and water molecules can move within the large cavities in the structure allowing ionic exchange and reversible rehydration plus they have a very high micro-porosity. These special features enable zeolite the ability to attract and absorb cationic materials such as plant nutrients for slow release.
Luckily for us in Australia, we have the best zeolites in the world for this purpose. When zeolite is added to soil it should be looked at as an asset as it is there permanently. The solid structure of Australian zeolite is very stable, it will not break down in the soil. Another important benefit of Australian zeolite is that it does not contain dissolved salts.
Much of the soil research carried out over the years has examined soft, geologically young (5 million years old) United States zeolites which have high levels of dissolved salts contained within their structure. In many cases these salts have to be leached out before the zeolite can be added to the soil. Also, under compression (vehicles driving over them and other mechanical activity), these soft zeolites can break down and lose their structure, basically destroying the porosity of the soil they are supposed to ameliorate.
Australian zeolites are hard (mohs hardness of 5-6), stable, geologically old (305 million years old) and have no dissolved salts. They also have a very high cation exchange capacity and high water holding capacity.
Click these links to go to our Landscaping page which gives more detailed information about zeolite's use in Soil Management and Turf.
Australian Organic Certified Zeolite
Zeolite Grades and Suppliers
Grade 3 Zeolite: A slightly coarser zeolite powder used in cattle feed, chicken feed, worm farms, turf, gardening, broadacre cropping and to absorb odours.
Grade 4 Zeolite: A blend of different sizes of zeolite from fine powder to small chips, a perfect blend for gardens, lawns and crops.
Contact details for suppliers:
Zeolite + Nutrients + Water
A move towards ecologically sustainable technologies has increased the importance of zeolite, a natural mineral with no known environmental downside.
Zeolite is now recognised as playing a vital part in ecologically sound soil management:
Zeolite is particularly beneficial in acid sandy or loamy soils with naturally poor nutrient and water retention abilities and where water is not reliably available.
Zeolite itself is not a nutrient; it is simply a nutrient carrier or facilitator. When the plant requires these nutrients they are released from the zeolite.
Positive molecules (cations) are attracted and become attched to the negative charge of the zeolite crystals. Molecules smaller than four angstroms enter inside the crystal, taking advantage of the enormous surface area. Thus, much less fertiliser is used as compared to application without zeolite and excess fertiliser components do not enter the local water supply during runoff.
The water trapped inside the zeolite structure remains available awaiting plant demand. Zeolite reduces watering frequency and helps with drought resistance.
Zeolite is an asset rather than a consumable. The structure of zeolite is insoluble, therefore once zeolite is applied to soils it lasts literally for centuries.
Zeolite Improves Soil
In an American article, Zeolites in the Landscape, Mark Whitelaw describes how zeolite improves soil. The link to the original site no longer works so here is a .pdf copy:
Zeolites in the Landscape by Mark Whitelaw