Wind and water erosion of soil

Heavy storms, strong winds and prolonged rainfall can cause surface run-off and soil erosion, particularly if not protected by cover. Find out what to look out for and how to prevent soil erosion.

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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