13 August 2026 ยท Field Guide
5 steps to a soil erosion risk assessment
Erosion risk is one of the few things on a farm that can be assessed properly with nothing more than a pair of boots, a spade, and half an hour after a decent rain shower, and it is worth doing on any field before deciding it needs no attention, because the visible evidence is often further downslope than people expect. This is not a substitute for a full catchment sensitive farming assessment, but it is a reasonable starting point that most farmers and consultants can carry out themselves.
What you need
- A spade
- Wellingtons, ideally after rainfall rather than during a dry spell
- A notebook, or a phone, for photos and notes
The steps
- Walk the field after rain, not before it. Evidence of erosion is easiest to see within a day or two of significant rainfall: look for rills (small channels cut into the surface), gullies, sediment fans at the base of slopes, muddy water pooling in low points, and sediment or discolouration in field drains, ditches, or at gateways.
- Assess slope and slope length. Longer, steeper slopes generate more runoff energy, and the direction of any cultivation, tramlines, or livestock tracks relative to the slope matters as much as the gradient itself: lines running up and down a slope concentrate water and accelerate erosion, whereas lines that follow the contour slow it down.
- Check how much of the soil surface is covered. Bare soil, thin or poorly established crop, heavily poached gateways, and compacted livestock tracks are all high risk points, since raindrop impact on bare soil is one of the main drivers of surface sealing and subsequent runoff.
- Dig a spade square and check the structure beneath the surface. A compacted layer a few centimetres down, visible as flattened, platy aggregates rather than a crumbly structure, reduces infiltration significantly and pushes water sideways across the surface instead of down through the profile. This step overlaps directly with a VESS assessment, covered in the next post in this series.
- Score and prioritise. Combine what has been found on slope, cover, and structure into a simple low, medium, or high rating for each part of the field, and focus attention on the highest risk points first, typically gateways, tramlines, and margins next to watercourses, where measures such as buffer strips, cover cropping, or reduced cultivation intensity make the most difference.
None of these five steps require laboratory analysis, and that is deliberate: an erosion risk assessment is meant to be something that gets repeated regularly, not something that happens once and is filed away. Fields change from season to season as cropping, stocking, and weather change, and the fastest way to catch a developing problem is to already know what the field looked like the last time someone walked it after rain.