Types of soil

Healthy soil is made up of four main components: rock or mineral particles, organic matter, air and water.

The organic matter in soil is generally referred to as Humus and is created by a process of living organisms breaking down the organic matter into a form which can be absorbed by plants. This process of decomposition is essential in making the nutrients available to plants as they can only absorb them is a gaseous or liquid form. A healthy soil, therefore, is teaming with living organisms from worms and beetles to bacteria, protozoa and fungi.

‘Good soil’ should also have a balance of the major elements known as NPK (Nitrogen, Phosphorus, and Potassium) sometimes referred to as Macronutrients. As micro-organisms break down organic material they also release other elements needed for healthy plant growth like copper, iron, zinc, iodine and cobalt also carbon-dioxide which is released into the air. Artificial fertilizers provide a quick fix but won’t build soil fertility in the long run.

Rock and mineral content make up about 90 percent of total volume and the remaining 10 percent is the organic matter (humus)

The rock and mineral content in the soil is made up of three main mineral types; sand, clay and silt. All types of soil have these in varying quantise and affect the soils ability to retain water, nutrients and air.

‘Sandy soils’ are easy to work but drain quickly so need lots of organic matter adding to them. ‘Clay soils’ hold moisture and fertility well but can be heavy and hard to work with. ‘Loam’ has a good balance of clay, sand and silt. In Loamy soil, these are grouped together with humus to form larger particles called aggregates. This type of soil is said to have a good ‘crumb structure’.

A quick way (although not always 100% accurate) to check what type of soil you have is to roll some up into a ball. If it doesn’t stick to your fingers, it’s probably a sandy soil. A gritty ball means Loam and a sticky ball usually means clay or silt soil.

A slower but more accurate way to check what type of soil you have is to take a jam-jar; half fill it with soil and then top up with water. Put the lid on the jam jar and shake the jar until all the soils is well mixed in with the water. Leave to stand and after about a day or so the soil should have separated into layers at the bottom of the jam-jar. This will allow you to see the proportions of sand, silt and clay (sand at the bottom being the heaviest, silt next and then the clay being the smallest particles as the top layer)

How to check acidity the acidity of your soil

The only real accurate way is to buy a soil testing kits from garden shop. The ideal PH is 6 to 7 for most soils, however, you can create a soils microclimate with a different PH for some edible plants.