Types of Soil and How to Improve it Naturally!

In Australia our soils are generally very poor, but for the home gardener they come in a variety due to imported/bought soils, builder ‘fill’, the soil type that was originally layered upon and any improvements made by previous gardeners. Below we’ve listed some common soil types that you might expect to find in your garden as well as some technical questions that are sometimes asked.

Read on to find out how to fix some of the problems that these soils present and how to enrich your soil into a thriving place of live microbial action so your garden can be glorious in its abundance!

What Is Loam or Loamy Soil?
Loam soil is made from a balanced mix of three main types of soil: sand, silt and clay soil . This combination makes it the most desirable soil for plant growth, it is easy to dig, stays moist and has a good amount of nutrients.

What is Humus Soil?
Humus is dark soil built up of many layers of decomposed matter, typically leaf litter, plant roots, insects, grass clippings, bark and compost. It has good structure, drains well and holds moisture well. For example, the soil in my vege patches would be considered largely humus soil and they need to be topped up yearly with organic matter and compost to keep them full as they further breakdown and plants and macro organisms consume the available nutrients.

What is Peaty Soil?
Peat soil is decomposed matter mostly from Sphagnum moss, so it is something we don’t really have in Australia. It is something that occurs in countries that typically have rich layering in their soil rather than small amounts of topsoil.

What is Sandy Soil?
Sandy soil has enough sand in it that it feels gritty to the touch. It drains well and is easy to cultivate. However, because it drains well it can dry out rapidly and lack nutrients as they run freely through the soil, for this reason, it is often called ‘hungry’ soil.

What is Silty soil?
Silty soil is soil that is made up of fine minerals particles, it will feel a little gritty. This can drain well if mixed with organic matter but can also form a bit of a sludgy soil that doesn’t have many air pockets which is not good for growth of plants in wet weather.
It dries out quickly in hot conditions and when fully dried out it can also form a bit of a ‘brick’ like consistency which is hard to grow in and hard to re-hydrate.
Many bought ‘soils’ are in fact silty soil and can be problematic to the gardener.

What is clay soil?
Clay soil is made up of fine mineral particles that bond to form a sticky, malleable ball when moist, they also have a low amount of organic matter present. When clay soil is dry it is solid and difficult to break up. As a result it drains poorly and can be hard to grow plants in.

What Is P Class Soil?
Is the classification given to soil on a block of land, to determine the soil movement prior to building and to indicate any additional engineering issues and costs. P stands for Problem – where the soil is soft clay or silt, has a risk of collapsing, is subject to erosion or landslip and/or has abnormal moisture conditions. An engineer is required to solve the issues prior to starting a build

What Is the Friction Angle of Soil?
To be technical, soil friction angle is a shear strength parameter of soils, it is used to describe the friction shear resistance of soils together with the normal effective stress. At its most basic level it’s a property that helps to quantify a soil’s shear strength.

How to improve your soil NATURALLY!
Below we have combined our ‘brains trust’ to outline some of the best ways to improve your soil naturally because at Food2Soil, we believe that natural and organic is best for you, your garden and the planet!

How to Enrich Poor Soil and Improve Soil Quality?
The answer to this is complex as it involves understanding why the soil is poor. For example, is it poor because it is lacking nutrients, drainage, and structure, lacking microbial life and is biologically dead, has an extreme pH, is battling super harsh conditions, or is maybe contaminated by builders’ waste? All these things and more can be contributing to poor soil.

It is probably better to understand that good soil should contain structure from organic matter, holes made by macro-organisms such as worms and grubs, particles of different size, a range of nutrients and bountiful amounts of live good bacteria and fungi. It should also have protection from the elements in the form of plants and/or mulch. So, the best thing to do is to make sure you have all these elements covered and you are well on your way to enriching your soil.

If you are after a short term fix, try adding a biologically live fertiliser like Food2Soil to get the ball rolling. By adding nutrients and biology to the soil it will recover a lot quicker.

To re-cap, check your soils deficits and decide whether you need to add: organic matter -(hay, leaf litter, compost, dead weeds, wood chip mulch) sand, gravel, blood and bone, chicken manure, wood ash, lime, fertilizer?

How to Break Down Clay Soil Fast/A-How to Improve Clay Soil?
The quickest way to break down clay soil is to get in there with a mattock, churn it all up, add plenty of organic matter (hay, leaf litter, compost, dead weeds, wood chip mulch) some sand, gravel, toss in a handfuls of gypsum and a biologically live fertiliser such as Food2Soil to increase microbial activity. Mix this all up and you will have well-draining, healthy soil in no time.

What Does Gypsum Do for Soil?
Gypsum is a naturally occurring mineral that helps break up clay soils which can make them more suitable for planting by allowing air and water into the soil. It is also a source of calcium and sulfur. It is a mined non-renewable resource.

How to Aerate Soil?
If soil is compact it is less fertile than it needs to be, so we need to aerate it. Best practice is to use a multi-pronged approach, this involves;

  • Breaking it up – use a pitchfork, mattock or shovel
  • If it is clay use gypsum or lime
  • Add organic matter- hay, leaf litter, compost, dead weeds, wood chip mulch
  • Add minerals of different particle size that won’t break down-sand, gravel, pebbles
  • Introduce biology – good bacterias and fungi that plants need to grow and thrive, try Food2Soil!

NB-if you are needing to aerate a grass lawn use a pitchfork and wiggle it back and forth, use ‘aeration sandals’ or you can buy or hire an aeration machine

How to Improve Sandy Soil?
Sandy soil leaks water, nutrients and becomes water repellant when thoroughly dried out so is a HUGE problem for gardeners. The best way to improve it is to add organic matter (compost, leaf litter, grass clippings, weeds, bark chips, hay) which will break down and hold moisture. If possible take clay from another area of the garden and add it to the mix. Make sure your soil is alive with good bacterias and fungi as this will promote good growth of plants, which will in turn increase the organic matter in your soil, to achieve this add good compost, worm castings or a biologically active fertiliser such as Food2Soil.

How to Add Nitrogen to Soil?
There are many ways to add nitrogen to soil, the easiest way is probably to add animal manure. Of most readily available manures, poultry manure has one of the highest nitrogen content, then comes horse and lastly cow manure. Be aware that uncomposted horse manure carries a very high weed seed burden as they are undigested in the horses gut.

Plant a ‘green manure’, or ‘cover crop’. Basically, you plant anything that will grow quickly covering the area which is then dug back into the soil to return nitrogen from the green, sappy growth and provide structure to the soil.

Plant nitrogen fixing plants that will deliver nitrogen back into the earth through nodes in their roots. These include all legumes, for example beans and peas.

Another great source of nitrogen that can be readily sourced is used coffee grounds! Ask your local cafe to put some aside for you and dig them into your garden. Beware though, you don’t want to end up with more coffee grounds than soil!

Use composts or products like Food2Soil to give an instant boost to nitrogen levels.

Weeds (without ripe seed heads) and grass clippings turned back into the earth can be a great and natural way of adding nitrogen back to the soil. Basically the same principle as the green manure concept.

Avoid using chemistry alone in the form of urea and other straight nitrogen sources, as this can burn plants and mostly evaporate into the atmosphere. They also pollute waterways and provide harsh conditions for the biology in our soil to flourish.

Is Leaf Litter Good for Soil?
Leaf litter is great for soil, it provides nutrients, structure and organic mass which holds moisture and provides food for macro-organisms such as worms and grubs. When introducing leaf litter to your soil you are also introducing a heap of invisible micro-organisms that exist throughout it which is fabulous for soil health.

What Influences Soil Colour?
Soil colour is influenced by its mineral composition as well as water and organic contents. Organic matter and iron oxides contribute most to soil colour, with organic matter making soil darker, while iron oxides produce a range of colours dependent on the oxidation state of the iron.

How Much Does a Soil Test Cost?
If you’re really keen to achieve gardening/ag production success, it’s a good idea to first investigate the type of soil you have. The cost of a soil test can vary greatly, but a standard soil test in Australia will cost around $390-$490.

However, for most backyard enthusiasts, following the above advice to remedy your garden’s soil is probably the simplest and most cost effective solution on your journey to a thriving garden!

Happy Gardening!

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