About gardening soil

To create good gardening soil, you need to understand what factors make soil a good medium for plant growth.

A good soil needs to provide anchorage, nutrients, moisture air and a range of biological interactions. These things all contribute to plant health and productivity; there is on single thing that will work like a "Silver Bullet". So, it is the ways in which soil does all these things that we need to understand - ie. the underlying 'System'.

Several factors contribute to how well a soil functions. The first one to look at in any gardening soil is its texture, which is mainly determined by the range of particle sizes that make up the soil.

However, it is the extent to which these particles clump together into aggregates that has the greatest impact on the character of the soil, we call this "Soil Structure".

Soil Structure

This is the tendency for soil particles to form aggregates gives the soil structure. This is most important in clay soils as the larger spaces between the aggregates allow for better drainage and easier cultivation, while the smaller spaces within the aggregate retain moisture and available nutrients for plants.

These pore spaces affect how water moves through the soil. This process has implications from the surface to deep within the sub-soil. It can affect the soil's vulnerability to leaching, the presence of impervious layers in the sub-soil that increase the tendency for the soil to become waterlogged and whether or not subsurface drains are required.

A strongly structured gardening soil also allows good root penetration and encourages the development of an active and diverse microbiological community within the soil. There are several factors contributing to soil structure, but what can we do to improve it?

In fact, this component of soil balance is the essential first step in the Mikhail System.

Soil Balance and the Mikhail System

Ted Mikhail is a soil scientist who did something few others ever considered. Instead of beginning with the assumption that soil fertility was based on a balance of Nutrients he started by looking at the physics of soil - its structure and friability.

What he discovered was that elements people had previously only thought of as Plant Nutrients also had another significant role in determining the physical nature of the soil.

Of course, the traditional view was that the soil particle sizes affect not just texture, but the entire physical character of the soil and, as such, it is not practical to try and fix problems in gardening soils.

However, the most important thing that Ted Mikhail's research has shown is that you are not stuck with the soil you have. It is possible - and in fact relatively easy - to improve any soil.

The Mikhail System provides a detailed understanding of both what causes soil problems and how they can be fixed.

Soil Problems

So what sort of problems do we see in soils and what does it take to make a "Good soil"?

Physical problems in gardening soil limit root access, nutrient uptake, moisture retention, drainage and biological activity. All these things are important for healthy plant growth, but they are often easily fixed.

But remember that we are managing a Living System. Unlike the process of overhauling worn out machinery, soil management takes time, patience and persistence. In fact it is probably better to think of "Growing Good Gardening Soil", rather than just fixing a problem.

Use the links below to find more detailed information on specific gardening soil situations:

1. Clay soil
2. Sandy soil
3. Soil acidity
4. Alkaline soil

Further Reading

Calcium Magnesium Ratio
This is an important but largely mis-understood measure in soils.

Using Lime, Dolomite and Gypsum
An important requirement for healthy gardening soil is to make appropriate applications of materials like lime, dolomite and gypsum.

What is the Cation Exchange Capacity (CEC)?
This is an important characteristic of any soil, but one that many people have trouble with - largely due to the technical jargon involved.

Soil Biology
Recent research has shown how soil biology can now be fully integrated into the soil balance relationship.

Reading soil test reports
To properly balance the soil according to the Mikhail System requires a fairly detailed soil test. This information will help you make the most of this valuable information.