Wind and water erosion of soil

Heavy storms, strong winds or prolonged rainfall can cause surface run-off and soil erosion, particularly if not protected by cover.

Soil erosion by water

Soil erosion by water is seen where rainfall exceeds the soil’s infiltration rate. Run-off and soil loss is particularly common where there is little crop cover, or the soil is compacted.

Surface run-off usually occurs during heavy storms or following prolonged rainfall.

It can happen on all soil types and slopes, but especially on sandy and chalky soils on moderate-to-steep slopes.

Gentle slopes are at a lower risk of rapid run-off and erosion, but can still see water flow quickly, particularly on long slopes where infiltration is slow.

Symptoms

Signs to look out for include:

• Overland flow after rainfall, which washes soil particles from the field
• Muddy run-off in the field, on adjacent roads or in watercourses
• Ponding in depressions in the field
• Waterlogged fields
• Rills or deeper gullying in the field, caused by extreme run-off

How to prevent soil erosion by water

Run-off and soil loss can be prevented by:

• Identifying paths for run-off
• Creating buffer zones (e.g. permanent strips of grass or rough vegetation) to slow down run-off and promote infiltration
• Planting hedges or building new ditches to restrict and control run-off
• Identifying and removing any existing compaction by looking at your soil structure
• Maintaining a good soil structure with continuous pores to depth so that water can infiltrate
• Avoiding fine seedbeds, especially in light soils
• Maintaining soil cover, wherever possible
• Cultivating across the slope, wherever possible, but be aware of complex slope patterns that may channel run-off

Soil erosion by wind

Wind erosion (wind-blow) is seen where dry seedbeds, in light sandy and peaty soils, are unprotected by cover (e.g., mulch or stubble).

Symptoms

Signs of soil erosion by wind include:

• Sand deposits on roads
• Airborne dust cloud − the finest particles (organic matter and clay) can travel great distances

How to prevent soil erosion by wind

To prevent wind erosion:

• If planting is delayed, leave seedbeds in a wet or cloddy state, or with ridges perpendicular to the prevailing wind direction
• Grow rows of trees or hedges to provide protection for soil and grow crops on the sheltered side
• Use cover crops to minimise the presence of bare soil
• Add organic materials (especially well-composted additions) regularly to improve soil aggregate stability

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