Grazing vetch and annual medics
Vetch can be grazed by livestock either early in the season as a green pasture or late as a dry forage. Vetches do not recover well from grazing so it is best to grow them as one large feed wedge then graze once. Like vetch hay, grazing vetch provides high quality feed for livestock. However, it is important to note that vetch infected with rust should not be grazed or cut for hay/silage as if consumed, may cause abortions in pregnant livestock.
In low rainfall areas annual medics are a valuable species in pasture mixes, especially with lucerne and in more recent times the inclusion of Uplands Hispanic cocksfoot. Medics provide high quality forage during autumn, winter and spring for grazing livestock. They are self-regenerating plants and persist in pastures even in tough seasons due to their hard seed levels. Blue green and spotted alfalfa aphids can kill or seriously reduce the production of medics, hence selecting an aphid tolerant variety is advised. Because livestock readily eat medic seed pods, medic pastures should be managed to allow seed set in their first year.
Green manuring benefits of medics and vetches
Vetch and annual medics are also commonly grown as a green manure crop. Forage vetch types and medics can produce large amounts of dry matter, which fix high levels of nitrogen and improve the soil profile when manured. Green manuring improves soil physical, chemical and biological properties which results in improved yields of following crops (Fageria, 2007). It is recommended that green manure crops are sprayed out in the middle of spring. Spraying out the crop with a non-selective herbicide also doubles as an opportunity to kill weeds before they set seed. This reduces the weed seed bank and problem weeds in following crops and is a valuable tool in managing herbicide resistance. Green manuring provides the most cost effective benefits if used once in every five to six years in intensive cropping rotations.