Vetch

Common vetch is a slender annual climber with tendril-tipped leaflets and pink to purple pea-like flowers. The pods are about 3 to 7 centimetres long and contain several small, round, speckled seeds that are roughly 3 to 5 millimetres across. It grows widely in cool temperate regions on a variety of soils and is valued for fixing nitrogen. The seeds taste bitter and slightly beany. Related species such as bitter vetch, Vicia ervilia, have been cultivated for human and animal food around the Mediterranean.

Vicia sativa is native to the Mediterranean region and western Asia and has spread throughout Europe, the Americas, Australia and other temperate regions, where it grows as a cultivated crop, roadside plant and weed. Archaeological finds show that vetches were gathered or grown in the Near East from early farming times, alongside lentils, peas and chickpeas. Today it is widely used as a green manure, a hay crop and a mixed pasture companion for cereals, and is grown in many countries, including Australia, Turkey and Spain.

Remains of vetch seeds are found at many Neolithic and later sites around the Mediterranean and western Asia, often with other pulses and cereals. Whether they were intentionally cultivated or simply harvested with other crops is debated. The Romans knew vetch as a fodder and cover crop, and farm writers such as Columella recommended it, while the seed is recorded as a poor-person's food in times of scarcity.

In the modern era, vetch was important in crop rotation systems before synthetic fertiliser, and it remains common in organic farming and conservation agriculture. Seeds can contaminate lentil or pea shipments, a recurring quality concern. Researchers have studied ways to detoxify the seeds, including soaking, heating and fermenting, because they contain compounds that limit their use for feed and food. In parts of the Middle East and Turkey, bitter vetch is still a local ruminant feed.

Vetch is used mainly as animal feed, as hay, silage and grain, and as a cover crop and green manure to enrich soil. The seeds are sometimes ground into flour or boiled in times of scarcity in parts of the Mediterranean and Middle East, and in some regions soaked and cooked, though vetch is not a normal modern human food. Flowers attract bees, and vetch is grown as a honey plant.

Vetch seeds are rich in protein and starch, comparable to other pulses, along with fibre and minerals, which is why they are valuable as animal feed. However, the seeds also contain antinutritional factors, including cyanogenic compounds and a neurotoxic amino acid derivative, which limit their use. Detoxification by soaking and heat can lower these levels but varies. For these reasons, common vetch is not recommended as a regular food for people, and lentils, peas or other cultivated pulses are far safer choices.