Chris Dalzell
Without topsoil we do not exist. I spend a lot of time on the road and the one thing that always concerns me is how we generally have not taken care on the soil below us.
Soil erosion is a result of over grazing and ploughing which both have a direct result on the plant material that holds the soil in place.
Topsoil is the upper layer of soil which contains the highest concentration of organic matter and micro-organisms essential for healthy plant life. It is composed of water, air, mineral particles, and organic matter. Once topsoil is gone it is gone forever: it takes between 500 and one million years to produce 3cm of topsoil.
When we start a new garden we first look at the quality of the soil.
Check the pH levels which will determine whether the soil is neutral, alkaline, or acidic. Desired pH levels would be between 5.0 to 6.2
Analyse nutrient levels of the soil. Once you know these, you can plan what you would like to plant because many plants require a particular pH or soil type to grow.
The two main ingredients for plants to grow are carbon and nitrogen. Nitrogen provides the energy and the carbon a tissue builder, both being necessary for suitable growth.
How to improve your soil
Composting
In simple terms, composting is the reduction of organic waste to humus. Fallen leaves sprinkled into a garden decompose over time and improve the soil quality. Animal manure, in particular chicken manure, plays a major role in providing nutrients to the soil.
Compost is more than a fertiliser and a soil conditioner. It is a continuation of life through leaves that fall from the trees, turn to compost, and return their nutrients to the trees that bore them.
Compost builds good soil texture and structure, enabling the soil to retain nutrients, moisture, and air for the support of healthy plants. It provides and releases plant nutrients, protects against drought, controls pH, supports essential bacteria and a healthy earthworm population, stops nutrient loss through leaching, acts as a buffer against toxins, controls weeds and retains moisture.
Recycling has become the new buzz word. If you took all your food and garden waste and turned it into compost, you would reduce your garden refuse by 100%. Composting is the greatest form of recycling and conservation.
Building soil structure
Compost builds good soil structure. If you have good garden soil it is because the individual particles of sand, clay, and silt group together to form granules which help to form a soil that is well drained and aerated. In sandy soils, the particles are too coarse. Clay soils are too compacted when wet thus not good for plant growth. Through composting you can change this soil profile. What you put into the soil is what you get out of the soil. Poor soil, unhappy plants. The higher the humus content of the soil the more moisture the soil can absorb and retain.
A well composted garden will also prevent plants suffering from lack of water during a drought. The soil particles are like a sponge that holds water which is absorbed by the tiny hairs on the roots of plants.
Composting improves the aeration of the soil, which is vital. Without air, soils become alkaline, organic matter content decreases, active humus becomes deactivated, nitrogen content is reduced, and the carbon/nitrogen ratio is lowered. Well aerated soils increase the amount of potassium taken up by plants which is a major macro-nutrient responsible for plant growth. All forms of plant growth through its macro and micro elements require oxygen for a healthy soil.
Compost also carries nutrients to your soil and plants that if done correctly, will require no other form of fertiliser and it’s free. As the organic matter begins to decompose it is like a slow-release fertiliser that feeds your plants.
How to make compost
Mother nature will do most of it for you but there are certain steps you need to follow. It can be done under the ground, above the ground, in bins, boxes or barrels. The basic requirements are for the heap to heat up which requires air, moisture, nitrogen, bacteria, heat, sufficient size, and plenty of organic matter.
Air: For the heap to get enough air is to keep turning it every week which also speeds up the decomposition process. Use chicken wire and poles to keep this just off the ground to allow air movement from the bottom. Lay plastic under the pile to catch liquids that drain out and can be put back to speed up the process.
Moisture: This is important but must not be too wet as it will drive out the air, drown the pile and wash away nutrients. The pile should be wet enough that if you take a handful and squeeze it, no drops of moisture should come out. Too dry slows the decomposition.
Nitrogen: Lack of nitrogen will prevent the pile from decomposing. Add about a fifth of chicken manure to the pile as it is very high in nitrogen and will work well with the garden waste, creating the heat to decompose the pile.
Bacteria: This exists in most raw ingredients but it’s best to add a thin layer of garden soil which provides micro-organisms and improves the texture.
Heat: Make compost in summer. You can cover the pile in winter with either hay or plastic.
Size: The larger the pile the easier it is to heat up. It should be at least 1metre by 3 metres in size.
Shredding: If you can buy a cheap shredding machine, shred all the leaves before putting them on the pile. It speeds up the process.
If you have fallen leaves and do not have space to make a compost pile, then take those leaves and spread them in your garden, especially on exposed soil areas. Happy Gardening.
- This article is sponsored by Chris Dalzell Landscapes, specialising in landscaping, consultation, plant broking and botanical tours. Send questions to [email protected] or visit www.chrisdalzellinternational.com
The Independent on Saturday