A Guide to Common Soil Types in Australia

From the sandy soils along Australia’s coastline to the clay and silt soils of its valleys and everything in between, soil type affects everything from water retention to nutrient requirements, and can have a huge impact on the success you have cultivating a lush, home lawn.

Let’s take a look at the most common soil types in Australia, where you’re likely to find them and the benefits and drawbacks of each type:

Sand Soils

Sand soils are common along Australia’s coastline, and can be found all across the country. The way the sand particles compact together in the soil profile allows plenty of tiny gaps due to the large grit size, which is why you might hear lawn lovers complain about sandy soils inability to hold on to nutrients as effectively as other soil types.

 Sandy soils are extremely common along the coast but can also be found inland around freshwater river networks or old water courses, as well as much further inland as towards the interior of the country as the colour starts to shift towards the iconic rouge hues of Australia’s Red Centre.

On a positive note, they’re known for their outstanding drainage and they’re very easy to work with – far easier to excavate than the back-breaking task of tilling up a clay soil!

Sandy soils will need slightly more nutrients than other soil types due to their issues with retention, and they lack the natural organic profile of clay or silt soils so a supplement regime that backfills these deficiencies will see your lawn thrive in sandy soil.

Clay Soils

Clay soils are far more common away from the coast, but that’s not to say that those with ocean views are immune from a clay base! Clay soils are excellent at holding nutrients and especially good at holding water, but this is also one of their great downfalls.

Unlike sand particles, clay particles are much finer allowing them to compact much more tightly, meaning that water doesn’t move through as efficiently which can cause flooding issues, in turn cultivating disease and leading to issues around compaction.

They’re also exceptionally dense, making them difficult to work with, but on the bright side this makes them very stable soils to plant in.

 Clay soils are best managed by frequent core aeration and backfilling the cores with sand, which allows you to highlight all the great features of a clay soil like the nutrient retention, while alleviating the drainage issues. This change to the profile is best done over time, and products like gypsum or liquid clay breakers on the market can assist with managing the profile of your clay soil.

Slit Soils

Silt soils are more common around river systems and old water courses, where sediment has settled along the base of the river, leaving beautiful fertile soil once the river changes course. Structurally, Silt soils are between Sand and Clay types in terms of particle size which makes them some of the most desirable to plant in.

Silt soils do a better job of holding water and nutrients than Sandy soils, but they’re not as prone to waterlogging or compaction which makes them an easy soil type to manage.

 From a cultivation perspective, they still benefit from core aeration like Clay soils and don’t mind a top up of organic matter like Sandy soils.

If you’re unsure about the soil type in your area, you can easily identify it using one of the following methods:

The Texture Text

One of the simplest ways to identify your soil type is to dig up a small patch, and to a decent depth – the top layer of soil is likely topsoil blown in or deposited from elsewhere combined with other organic matter, and won’t accurately depict the soil type at the root layer.

Put the soil into a jar with water and shake well, then leave it to settle. This will separate all the different soil types and particles in your sample and tell you which soil type your sample is biased towards.

Clay and silty soils will leave the water cloudy with sediment at the bottom of the container, while sandy soils will leave the water mostly clear.

Soil Colour and Moisture

It’s also possible to visually gauge which soil type you’re working with. Soil samples with heavy clay content will feature the dense, coloured ripple of clay throughout them, and will be sticky to touch and have no issues holding their form.

Sandy soils will be coarse to the touch and won’t hold their form if you squeeze them tightly into a ball in the palm of your hand, while Silty soils will hold their form better than Sand, but not quite as well as Clay.

You can also try a drainage test by pouring water on to the soil and gauging how long the water takes to drain from the surface, but this method isn’t exceptionally reliable.

The health of your lawn depends heavily on the structure and composition of your soil, and working with the confines or optimizing your soil composition will go a long way to improving your lawn health, and can even save you money on excess nutrients or watering in the long run.

Nutrient availability is heavily impacted by soil type, so it’s important to construct your supplement program accordingly, as Sand soils will require more nutrition than a Clay soil which holds on to nutrients better.

How to Improve Your Soil Quality

The good news is that you can improve almost any soil type over time to create the best environment for your lawn. Regular aeration is key for compacted soils like clay and silt, as it helps break up the soil and allows air, water, and nutrients to reach the roots. Top dressing with organic matter can boost both nutrient content and soil structure, enhancing sandy and loam soils as well.

Although aeration and top-dressing won’t entirely change your soil type, they can make a dramatic improvement in its quality, helping your lawn thrive in any Australian soil.

Soil Amendments

Soil amendments add exogenous nutrition to your soil and they can be as simple as a slow release fertiliser, a supplement focussed on overall soil and root health like LawnPride’s Rootmaxx or Kelp-ER or something that’s as granular as their Tracemaxx product, which adds vital trace elements to assist with making key nutrition more bioavailable.

Mulching

Mulching your grass clippings back into your lawn can be a way of keeping exogenous nutrition in the lawn, as the grass clippings release pent up nutrients as they break down, not dissimilar to composting in a garden. Contrary to popular belief, mulching your clippings back into your lawn does not contribute to thatch.

Care for Your Lawn with myhomeTURF

Mulching your grass clippings back into your lawn can be a way of keeping exogenous nutrition in the lawn, as the grass clippings release pent up nutrients as they break down, not dissimilar to composting in a garden. Contrary to popular belief, mulching your clippings back into your lawn does not contribute to thatch.

Visit the myhomeTURF online store for everything you need to care for your soil and your lawn.