Small Oat/Shetland Oat & Common Oat

Small Oat or Shetland Oat (Avena strigosa Schreb.)

Small, black or bristle oat (Avena strigosa) is a historical crop of marginal soils that has largely disappeared from Northern Europe (Weibull et al. 2001). Formerly widely grown on the poorer soils in the UK, and included in plant breeding programmes in Wales, cultivation of the small oat has now almost ceased (Chater 1993, Scholten et al 2004).

The major remaining area of cultivation in the UK are on the Uists and Benbecula in the Outer Hebrides where over 300 hectares are planted every year with mixtures of small oat, rye and bere barley. Smaller areas of cultivation are scattered over Lewis and Harris, Tiree and Islay. The use of mixtures is an ancient agricultural strategy to safeguard crop yields in a highly risky growing environment.

On the Hebrides A. strigosa it is known as small oat, black oat or, in Gaelic, Corce beag, in contrast to Avena sativa (common oat) which is called big, mainland or white oat.

Its cultivation on the Hebrides is for the production of winter feed for animals and is restricted to very light, highly alkaline machair soils. The alkalinity and nutrient deficiencies, such as manganese, make it difficult to grow common oat without additional nutrients. In contrast, the small oat yields well under these conditions without the need for additional nutrient. The small oat has survived thanks to its adaptation to very marginal growing conditions.

Cultivation of low input local cereal varieties (landraces) make an important contribution to biodiversity conservation of the machair, a man-made habitat unique to the British Isles. A large part of the machair is protected with a Western Isles Local Biodiversity Action Plan (LBAP) which advocates support for the local cereal varieties.

On the Northern Isles, A. strigosa is called Shetland oats or aets.  On both island groups it is used as winter feed.  In Shetland, the oat straw is primarily used for making traditional straw baskets called “kishies”, thatching and for the straw backs of Fair Isle chairs.  The Heritage Crafts Association has recently “red listed” Fair Isle strawback chair making and Kishie making as critically endangered crafts. This is in part due to a severe shortage of Shetland Aets being grown in the isles - in recent years, poor weather conditions and devastation by birds has led to the loss of seed and eventual retirement of some growers. There is an urgent need to multiply existing seed stocks before new and experienced growers can be encouraged take up growing.

On Orkney its occurrence is associated with the traditional Orkney chairs for which the black oats provide strong straw of a beautiful color.

References

Chater, A.O. (1993) "Avena strigosa Schreb., Bristle Oat and other cereals as crops and casuals in Cardiganshire, V.C. 46", Welsh Bulletin of the Botanical Society of the British Isles (BSBI), no 55, 7-14.

Scholten, M., Maxted, N., Ford-Lloyd, B. (2004) UK Inventory of Plant Genetic Resources for Food and Agriculture, University of Birmingham available from: http://www.brockwell-bake.org.uk/pics/UK_inventory.pdf

Scholten, M. (2007) "Uist cereals attract research interest. Part 1: Small oat", Am Pàipear, March.

Scholten, M., Maxted, N., Ford-Lloyd, B., and Green, N. (2008) "Hebridean and Shetland Oat (Avena strigosa Schreb.), and Shetland cabbage (Brassica oleracea L.) landraces: occurrence and conservation issues", BIOVERSITY/FAO PGR Newsletter, 154, 1-5, available from: http://www.bioversityinternational.org/fileadmin/PGR/article-issue_154-art_1-lang_en.html.

Weibull, J., Johansen Bojensen, L.L., Rasomavicius, V. (2001) "Avena strigosa Schreb. in Denmark and Lithuania", BIOVERSITY/FAO PGR Newsletter, 131, 1-4, available from: http://www.bioversityinternational.org/fileadmin/PGR/article-issue_131-art_66-lang_en.html.