Composition
South Africas soil mantle consists of a large number of soil bodies. There are 5 topsoil horizons-
- 1. Organic O
- 2. Humic A
- 3. Vertic A
- 4. Melanic A
- 5. Orthic A
There are 25 subsoil horizons.
The most common topsoil type in our specific area is the Humic A and Orthic A. Humic A is a freely drained topsoil which has accumulated organic matter. This topsoil is a well weathered soil not displaying the very dark properties of the Vertic and Melanic topsoils. Orthic A does not have a distinct character as the other 4 topsoils and is therefore considered ordinary or normal.The colours of the Orthic A will vary widely. JUST BECAUSE A SOIL IS RED IN IN COLOUR DOES NOT MEAN ITS CLAY OR A SUBSOIL.
At Viewpoint Farming we want to guarantee all the soils sold are the top 150-300mm soil, not subsoils passed on as a topsoil.
Uses:
- Topsoils are used to lift and raise or level areas in ones garden. Wherever there any changes on a property due to building alterations or where soil has been washed away by excess rain and when shaping a new garden.
- Topsoil mixed with compost makes an excellent potting soil , it is heavier than your bark based potting soils and preferred by many for large ornamental pots and planters and flower boxes.
- Topsoil is NOT a good lawndressing product on its own. It needs to be mixed with compost in order to nourish the lawn. It should only be used on the lawn whenever levelling of the lawn is required.
The only disadvantage of topsoil is that it is not a quaranteed weed free product. The only way to quarantee such a soil is by methyl bromide which is not environmentally friendly and economical. The most common weed is Nutsedge and the way to counter it is applying agricultural lime which reduces the acidity of the soil which the weeds prefer. Level your area first then plant the lawn on top redces the chances of the weeds growing through.
Topsoil + All Topsoil Products
- The only 100% weed free topsoil is one which has been sterilised (heat > 80c) or fumigated.
- The disadvantage of a 100% weed free topsoil, is that the soil is a living medium and so by sterilising it, you are killing beneficial organisms (helpful fungi & bacteria) that are really needed.
- Topsoil is screened finely eliminating any roots of weeds, but weed seeds can still occur.
- We have recommended using herbicides + weedicides from suppliers, should any weeds germinate.
- In certain instances, over seeding is necessary to keep lawn thick and to discourage weeds. Using Only Lawn Dressing will not be sufficient.