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

Appendix 2. Classifying land use of observed erosion sites (Evans’ data) into broad land use types.

A simplification of the land use at the sites with observed erosion was made, depending on the way the soil is managed and disturbed (and thus at risk of erosion).

Land Use
LU_categories

Apple_Orchard
Woodland

Asparagus
Intensive arable

Bare_Soil
Extensive arable

Bare_Soil
Intensive arable

Beetroot
Intensive arable

Black_Current
Horticulture

Brassica
Intensive arable

Brussell_Sprout
Intensive arable

Cabbage
Intensive arable

Carrots
Intensive arable

Cauliflower
Intensive arable

Daffodil
Horticulture

Fallow
Extensive arable

Field_Bean
Extensive arable

Field_Vegetable
Horticulture

Fodder_Crop
Extensive arable

French_Bean
Horticulture

Fruit_Bush
Horticulture

Garlic
Horticulture

Grass
Improved grassland

Hops
Extensive arable

Kale
Extensive arable

Ley_Grass
Improved grassland

Linseed
Extensive arable

Lucerne
Extensive arable

Maize
Intensive arable

Maize / Carrots
Intensive arable

Market_Garden
Horticulture

Mustard
Extensive arable

Oats
Extensive arable

Onions
Horticulture

OSR
Extensive arable

Parsley
Intensive arable

Parsnips
Intensive arable

Peas
Extensive arable

Permanent_Grass
Improved grassland

Potatoes
Intensive arable

Potatoes_Parsnips
Intensive arable

Root_Crop
Intensive arable

Rose_Bush
Horticulture

Rye
Extensive arable

Soft_Fruit
Horticulture

Spring_Barley
Extensive arable

Spring_Beans
Extensive arable

Spring_Cereals
Extensive arable

Spring_Crop
Extensive arable

Spring_Oats
Extensive arable

Spring_Wheat
Extensive arable

Strawberry
Horticulture

Sugarbeet
Intensive arable

Swede
Intensive arable

Turnips
Intensive arable

Wheat
Extensive arable

Winter_Barley
Extensive arable

Winter_beans
Extensive arable

Winter_Cabbage
Intensive arable

Winter_Cereals
Extensive arable

Winter_Oats
Extensive arable

Winter_Wheat
Extensive arable

Winter_Wheat_Barley
Extensive arable

Notes: Combinable crops, with soil disturbance only during land preparation, and relatively few field operations, were classified as “extensive”. Other crops that are managed in a similar way (e.g. peas) were classified as “extensive arable”. Whereas root crops, such as potatoes and similar, which require digging up with huge machines and cause a lot of soil disturbance, were classified as “intensive”.

‘Horticulture’ was used for those crops that would be much more based on labour inputs than on machinery, and which were smaller scale, more like market gardening. These include very highly managed land with polytunnels, soft fruit, flowers etc….

Maize was originally classified as extensive rather than intensive, to reflect the operational management of the systems and in particular, the degree to which soil is disturbed during land preparation and harvest. However, the consensus was that maize is associated with high erosion risk due to: high % bare soil; slow / delayed establishment in cold springs; row crop (often up / down slope orientation); often grown on marginal / sloping ground; late planted; late harvested (often on wet soils, liable to compaction and with no time for overwinter cover crop etc.). Although the area of maize production in Scotland is small, it is generally seen as the most risky crop in terms of erosion vulnerability (see p18 of the Valuing your soils booklet: https://www.farmingforabetterclimate.org/wpcontent/uploads/2018/02/Valuing_Your_Soils_PG.pdf). As a result and for the purposes of this current project, maize is classified as ‘Intensive arable’.