Developing a method to estimate the costs of soil erosion in high-risk Scottish catchments: final report

Appendix 11. Soil erosion mitigation measures

Table 78. Options for the mitigation of soil erosion

No mitigation
no mitigation applied

Cover crops- Winter cover
Temporary cover is established in-between main crops in order to protect soil. It can also involve under-sowing whilst the main crop canopy establishes.

Cover crops - Under sown
Temporary cover is established in-between main crops in order to protect soil. It can also involve under-sowing whilst the main crop canopy establishes.

Mulching
Crop residues or stubble from harvested crops are left in place to minimise run-off.

High density planting
Increase in seeding rates ensures maximum cover, reducing exposure. Reduced/ minimum tillage

Soil structure is kept more intact reducing erosion risk. Noninversion techniques also preserve the soil surface by keeping some vegetation in place. Reduces tillage erosion and translocation and prevents water erosion

Zero tillage
Seeds are planted by a drill, avoiding the need for tilling. Previous crop residue is retained and soil structure is maintained. Impact of erosive forces is reduced and no tillage soil translocation occurs

Cultivate across slope
Across slope cultivation reduces run-off erosion.

Tramline management
Cover cropping and physical barriers such as mulch can be used to reduce tramline soil exposure, reducing run-off. Not using tramlines until the spring will also prevent erosion risk.

Loosen compacted soils
Use of shallow spiking, slitting or subsoiling on cultivated compacted or capped soils increases surface roughness and prevents erosion by water run-off by increasing infiltration.

Leave autumn seedbeds rough
Leaving the seedbed rough will increase water infiltration and reduce run-off risk.

Convert arable to grass
Arable land converted to permanent grass, which would reduce wind and water erosion and tillage would no longer occur.

Agro-forestry
Tree planting within arable and grassland systems

Biomass cropping
Arable land converted to biomass cropping, which would reduce wind and water erosion and tillage would no longer occur.

Field layout
Smaller field sizes reduce wind acceleration and slope length reducing erosion. The movement of soil by tillage may also be reduced.

Early harvesting
Crops are harvested in September when the soils are drier rather than October. Reduces compaction, soil structural damage, and surface run-off.

Timeliness
Arable land is cultivated for spring crops rather than autumn, reducing the likelihood of harvesting in wet conditions which increase erosion risk when the soil is bare and increases coextraction.

Crop rotation
Rotation of high erosion risk crops with low erosion risk crops, such as ley grasses, can help to establish organic matter and improve soil structure.

Shelterbelts
Establishing rows of trees or hedgerows to provide shelter from wind and airborne erosion. They also trap sediment and lower surface run-off.

Establish new hedges
Based on new hedge establishment, installing new gateways and back fencing

Reduce the length of the grazing day/grazing season
Requires indoor areas where stock can be kept, increased labour costs of housed animals and due to increase in proportion of grass utilised by cutting.

Reduce field stocking rates when soils are wet
Assumed that no additional slurry storage was needed.

Move feeders at regular intervals
Costs based on moving feeding troughs on a fortnightly basis for dairy/beef cattle during the grazing season and for pigs throughout the year.

Construct troughs with firm but permeable base
Construct firm but permeable base for existing troughs (large round troughs for dairy cattle and conventional troughs for beef, sheep and pigs).

Reduce overall stocking rates on livestock farms
Reduce total number of livestock on the farm

Fence off rivers and streams from livestock
Fence off rivers and streams from livestock.

Construct bridges for livestock crossing rivers/streams
Construct bridges for livestock crossing rivers/streams.

Re-site gateways away from high-risk areas
Move gateways to lower risk areas

Farm track management
Based on digging out a soakaway and installing French drains across farm tracks, plus maintenance and clearing out every four years

In-field buffer strips (6m)
On sloping fields - grass buffer strips are established along the land contour, at the bottom of valleys or on upper slopes to reduce surface water flow.

Riparian buffer strips
Grass or woodland strip act as a natural buffer to reduce the transfer of pollutants from agricultural land to water. They can be used to restrict direct livestock access to watercourses and can trap sediment

Geotextiles/ grassed waterway
Geotextiles are permeable fabrics which can be natural or synthetic. They can be used to protect emerging vegetation, underline swales and waterways to protect bare ground from erosive forces.

Lined waterways or swales
Lining waterways or swales with vegetation (usually grass) increase resistance against overland flow. Geotextiles can be used prior to vegetation establishment. Reduces particle detachment and transport of eroded material.

Earth banks/physical barriers
Earth banks and other physical barriers such as ponding sites may be used to intercept run-off flow. Reduces the impact of overland flow velocity, thus indirectly reducing erosion.

Irrigation
Keeping the soil moist reduces wind erosion.

Establish coarser seedbeds
A coarse seedbed reduces run-off and erosion by maintaining soil structure.

Increase soil organic matter
Increased soil organic matter decreases erosion risk and encourages water infiltration. Fertility is also increased. Cover crops, green manures and mulches can be used.

Furrow press
Light pressing and soil compaction can increase soil cohesion reducing wind erosion.

Addition of clay sized particles
Mixing clay rich soil into the soil improves soil stability reducing erosion by wind and water. Application rates of 4001000t/ha are likely to be needed depending on the soil.

Synthetic stabilisers
Soil stabilisers such as PVA (polyvinyl acetate) emulsions and PAM (polyacrylamides) can be sprayed onto sands after drilling. This provides cohesion and protection against wind and rain erosion.

Establish and
maintain artificial wetlands

Construct wetlands with fences and channels to capture runoff and sediment.