Characteristics of different soils

Whether it warms quickly, is prone to erosion or holds moisture, your soil will dictate the methods you use from cultivation to harvest and the yields you achieve. Learn the key properties of the six main soil types.

• Largest soil particle at 0.06–2 mm
• Large air spaces between particles
• Free circulation of air and good drainage (refer to Figure 1)
• Warms up quickly in spring and has a long growing season
• Drought-sensitive, often acidic
• Weak structure, so may slump or cap
• Prone to compaction by deep cultivation or harvesting in wet weather
• Can suffer from runoff and erosion by water and wind

Figure 1. Air space and water movement in sandy soils

Figure 1 shows a cross-section of sandy soil made up of large, loosely packed sand particles. The wide gaps between the particles create large spaces that allow air and water to move easily through the soil. Three arrows indicate water moving downward and through the gaps between particles, showing that water drains freely.

• Smaller than sand, but bigger than clay, at 0.002–0.06 mm
• Air spaces and water channels are more restricted than in sandy soils (refer to Figure 2)
• Fertile, fairly well-drained and holds more moisture than sandy soils
• Easy to cultivate, except in dry conditions, but easily compacted
• Prone to capping, so needs careful management
• Damaged when worked or grazed in wet conditions

Figure 2. Air space and water movement in silty soils

Figure 2 shows a cross-section of silty soil consisting of medium-sized particles. Three arrows indicate water moving downward through the soil, but movement is restricted forcing water to pool as gaps and channels are narrow.

• Smallest particle at less than 0.002 mm
• Restricted air and water movement, so can lie wet for long periods (refer to Figure 3)
• Contains high levels of nutrients if drainage is adequate
• Easily compacted if poached while wet
• Bakes hard in dry conditions
• Unsuited to ploughing in spring if subsoil remains wet
• May crack in dry or frosty conditions, which can alleviate compaction

Figure 3. Air space and water movement in clay soils

Figure 3 shows a cross-section of clay soil made up of very small particles. The particles are tightly packed together, leaving only narrow, irregular channels between them. Three arrows indicate water attempting to move downward through the soil, the water channels show restricted flow that does not drain freely.

• A mixture of sand, silt, and clay particles
• Good water retention and nutrient holding capacity
• Generally easy to work

• High in organic matter
• Wet and often acidic
• Easily compacted when wet
• Prone to drying and erosion if drained
• Unimproved peat has high biodiversity value, stores carbon dioxide and should be preserved

• Also classed as alkaline soil
• Often shallow and free-draining
• Not all nutrients are available to plants because of high soil pH