CONSERVATION AGRICULTURE Growing vetches

Vetch has enormous potential as an annual legume species, especially if rotated between two summer-growing grain crops.

Vetches are annual legumes that have either a creeping or ranking growth habit. They are a winter growing species, are thin-stemmed and have predominantly purple flowers.

Currently, the most common vetch types cultivated in South Africa include purple vetch (perswieke or Vicia purpurea/Vicia benghalensis), grazing vetch (weiwieke or V. dasycarpa), common vetch (gewone wieke or Vicia sativa) and hairy vetch (harige wieke or V. villosa).

These vetches can be used for silage, hay and grazing, say Dr Wayne Truter et al in their article on vetches for Grain SA.

Vetches are commonly grown in dryland wheat production areas. These species are well adapted to a variety of soil types, but do not particularly tolerate waterlogged conditions.

The best time to sow vetch is from December to March. This species is particularly sensitive to acid soils, so it is advised that soil be limed properly prior to planting. Purple vetch is mostly grown in winter rainfall conditions and used specifically for silage or hay, and is not suitable for grazing purposes, say Truter et al.

Grazing vetch is more tolerant of cold winters than other vetches and more suited for grazing. It develops quickly and is more adapted to poor and acid soils. It also has the potential to reseed itself.

Common vetch is used for hay and silage too. This vetch produces pods that are grazed by sheep.