Know Your Soil

Soils are made up of the following components:

  • Minerals/Sand
  • Silt
  • Clay
  • Water
  • Air
  • Organic matter
  • Living organisms.

Soil Profile & Horizon:

A profile is the vertical section showing make-up. The soil horizon is the horizontal sections –

  • Topsoil
  • Subsoil
  • Parent rock.

Mineral Characteristics:

Rolling a sample of the soil in your hands can tell you a lot about it:

  • Sand: feels gritty, free draining, easy to work.
  • Silt: soapy feel, fair drainage.
  • Clay: feels sticky, poor drainage, negative electrical charge.

Establishing texture:

    Does the soil form a ball?

  • NO → Sand
  • YES ↓
            Does the soil form a ribbon?

          • NO → Loamy Sand
          • YES↓

    How long is the ribbon? (Rolling a sample of the soil in a sausage shape can also indicate what type of soil you have)↓

Less than 2.5cm (1”) long 2.5-5cm (1-2”) long More than 5cm (2” plus) long
Smooth & Slippery Silt loam Silty clay loam Silty clay
Gritty Sandy loam Sandy clay loam Sandy clay
Neither loam Clay loam Clay

pH Value:

A pH of between 6.5 and 6.8 is ideal. Most crops are tolerant of a lower pH value (acidic), except for brassicas which prefer a more alkaline soil.

Composts and Manures:

These come in many forms but basically these are the main forms:

  • John Innes Composts – Traditional mix containing soil and nutrient balance.
  • Multi-purpose Composts – Blend of peat and wood fibres in varying percentages.
  • Peat free / Organic / Composted green waste – made from a range of peat free products, such as Biodegradable waste, coir, wood fibres etc.
  • Manures – Horse/cattle/poultry/Leaf mould.

Homemade composts

Soil Structure: Sand has little structure, whereas Clay structure is good but difficult to maintain. Organic matter helps bind soils and helps them warm up quicker. Lime can aid clay structure. Sand has a longer cultivation window than Clay.

Remember – plant roots require a warm, moist, friable and porous environment in which to thrive.

To see a full list of all our handy fact sheets click here