Improving Your Soil

Soil is incredilby valuable to a gardener; it can determine what you can and can't grow. It is the beating heart of everything, whether your passion is lawns, edibles, natives or flowers, soil is where it all begins. 

What is soil? 

Soil is "the upper layer of earth in which plants grow, a black or dark brown material typically consisting of a mixture of organic remains, clay and rock particles." - Oxford Language. 

It consists of air, water, organic matter and mineral matter. 

Lots of people get confused with soil and dir, thinking they are both the same, but wherer soil sustains life, encourages and nurtures growth, dirt does not. Dirt is that lifeless substance you find under your fingernails or that's on those pawprints your dog just put on your doona! It is usually compacted, hard and difficult to grow anything in. Soil has dirt in it, but dirt does not mean soil. Dirt is quite literally sand, silt, and clay, and if water is added it doesn't clump together well. It lacks microbes, fungi, bacteria, insects and the organic matter of soil, which is a self-sustaining ecosystem. 

Soil structure is highly important, good soil structure allows water to pass and drain whilst being absorbed, it allows aeration around plant roots and gases to be exchanged. 

"Soil structure refers to the way soil particles group together to form aggregates (peds)." - qld.gov.au Aggregates vary hugely in size from small crumbs to large blocks. 

DID YOU KNOW: A ped consists of mineral particles and is held together by electrical charges on the surfaces of minerals and organic matter. 

 

What's what though? 

Sand - is "a loose granular substance, typically a pale yellowish brown, resulting from the erosion of siliceous and other rocks." - Oxford Language. Sand consists of rock and mineral fragments, usually quartzanywhere from 0.05 to 2mm in diameter. 

 Clay - "high percentage of fine particles and colloidal substances and becomes very sticky when wet." - Merriam Webster. 

Silt - "Fine sand, clay and other materialcarried by running water and deposited as a sediment." - Oxford Language. 

Soil textures vary massively also, depending on the composition, for example, a sandy soil have have an extremely different texture to that of a silt soil. Sand will feel coarse and 'chunky', whereas silt will feel more like flour. The percentage of sand, silt and clay determine this texture. These are the inorganic compounds which form our aggregates, aggregates are bonded together by the organic materials. 

DID YOU KNOW: In Western Australia the Department of Agriculture and Food states most of the state's soils can be classified into one of the 60 defined soil groups! You can read more about this at http://library.dpird.wa.gov.au/cgi/viewcontent.cgi?article=1347&content=rmtr 

 

The basic groups/ types of soil are: 

. Sand 

. Sandy Loam 

. Loam 

. Clay Loam 

. Clay 

. Silt 

. Silty Loam 

Most gardens will fall somewhere very briefly in these groups. Apologies to those who have rock or gravel, I've been there, it's horrible! 

In most cases, rarely does anyone have the perfect loam soil, so inevitably we will have to improve our structure slightly, or greatly, depending on where you are, so we can grow what we desire. Personally speaking, and for example, I have hydrophobic sand - meaning it repels water. This comes with small pockets of silty clay, but in very specific areas, mostly around the foundation of the house, and about 10 inches down, in areas I have rock. This is not ideal at all! So I'm starting the long process of improving my soil structure. 

Neutrog

How do we improve clay soils. Clay is excellent at holding water, probably too excellent, it leads quickly to waterlogging and lack of aeration, which can cause it's own problems. You really need to try and break apart that clay. Gypsum, commonly called clay breaker, does just that. It helps break up the clay particles, it does this by encouraging the clay particles to clump together, forming bigger clumps, and allowing better aeration and water penetration. 

Just like anything else, organic matter is key. Digging in plenty of manures and composts disrupts those fine clay particles. As with clay, organic matter is key in sandy soils. Regularly add organic matter to the ground, and instead of gypsum clay, we use bentonite. 

Soil wetters are also a very good idea, as sands tend to be hydrophobic. 

If you have silt-based soils, lots of compost, mushroom compost and composted horse manure and cow manure can be added to assist. 

Humus is what's left overonce plants and animals have been decomposed by organisms such asworms, fungi, acteria and micro-organisms. It is usually beautiful, spongey, rich and full of goodies to improve that undesirable soil you currently have. When it comes to humic substances, humates occur naturally in many soils. They aid in binding nutrients together and breaking down organic matter, which in turn provides more nutrients for the soil and plants in it. They also aid in improving soil structure, retaining water, and improve nutrient availability and pH. 

There are several productsavailable  on the market to help you with that undesired soil: 

. Baileys Soil Improver 

. Eco-humate 

. Humate 400 

. Gypsum - Clay Breaker 

. Bentonite - Sand to Soil 

. Richgro Rock Minerals 

. Dynamic Lifter Soil Improver 

. Compost - Many different brands, please 

  don't just buy the cheapest. 

. Richgro Mushroom Compost 

. Seasol Biochar 

. Manure - composted 

Any nursery or home improvement store will have some variation, even if you're not sure what type of soil you have, you can always add organic matter! 

Now you remember I have that horrible hydrophobic sand, well this is my plan of conquering it. 

Firstly I need to try and break the oil layer that is causing my sand to be hydrophobic, as I need the water to penetrate the ground, rather than runningoff or flooding. For this I'm using a soil wetting agent, and lots of (1,012m2 block). Out the front of my property I'm using Scott's Every Drop, I chose this one, as it has a large portion of coir present which will eventually break down and add organic matter to my soil. Out the back of my property, I am using the Scott's Every Drop and Richgro Ezi-wet, which is an aquatic friendly wetting agent but it's more synthetic. I will likely have to do this a few more times, due to severity of the hydrophobia. 

I am also ordering some bentonite clay, commonly known as 'Sand to Soil'. Bentonite is a naturally occurring mineral which essentially encourages sand particles to clump together, providing better drainage and nutrient holding capacity, and gives them back to the plants. It also means when I add more organic matter it will hold better, rather than disappearing through my sand. 

I will then start to add my organic matter and beneficial microbes back into the soil. 

There are several different products I can use, and this depends on what I want to achieve. In the back portion of garden, I would love to create an edible oasis, lots of fruit trees, herbs and veggies, whilst my partner wants a patch of lush lawn. So, I need to create something that is going to hold nutrients and water nicely. Whereas my front garden will be lots of natives, with the odd 'exotic/traditional' shrub. In this case, my soil doesn't have to be so rich as most Australian natives are used to sandier environments.

Ways and products to improve my sandy soil:

. Compost - bagged and liquid

. Mushroom compost

. Leaf litter

. Grass cuttings

. Humus, humic acid and humates

. Peat moss

. Course

. Cover crops and green manure crops

. Manures

. Clay - Bentonite (not gypsum)

. Soil conditioner

I will be using a combination over time. I am a big fan of composts, especially mushroom compost, it's lovely and rich, full of beneficial microbes and holds water beautifully. Like I mentioned above, bentonite clay will be added by the bag load, and I will have to do at least another two rounds of soil wetter, I think. Luckily for me, I know a few people with sheep and horses, so I can compost down manure and add that frequently to the soil. At the very back portion of my yard, I will be adding chickens for manure, they will also scratch it around the soil and dig it in for me. I will also plant a chicken friendly cover crop consisting of:

. Buckwheat

. Purslane

. Subclover and clover

. Chicory

. Bok choy

. Cocksfoot

. Endive

. Kale

. Millet

. Plantain

. Sunflower

I might add a bit of a green manure crop too, which will also include oats, brocolli, fenugreek and pod vetch. This will assist in enriching and protecting the soil.

It will then be a case of repeatedly adding organic matter of different varieties, soil conditioners, and wetting agents. It will be a long process, but well worth it.