Santiago Spineless Burr Medic
Early to mid-maturing hard seeded Medic. It is an autumn-to-spring growing annual pasture legume which has good waterlogging tolerance, germinating after autumn rains, ﬂowering in spring and setting seed in late spring. It is a semi-prostrate annual, 15-40 cm high, with multiple lateral branches starting from near the base.
Once established it will maintain a bank of seed reserves in the soil and will self-regenerate from that seed bank. It has some tolerance of false breaks as seed softening tends to occur later in the summer/autumn period.
It is more productive and persistent in low rainfall areas than sub clover.
Santiago is relatively tolerant of transient waterlogging and moderate salinity compared to other medics.
It is palatable at all growth stages with high nutritive value and high protein content making it an outstanding complementary legume component for summer growing grass pastures in the subtropics. It is very tolerant of heavy grazing and produces excellent green feed for growing and ﬁnishing livestock. Digestibility ranges from 55-75% DMD, (equates to ME energy of 8-10 MJ/kg DM) and crude protein from 17-23% depending on growth stage. In general animals make better live weight gains and wool production on legumes than grasses, because of higher intake and more eﬃcient utilisation of high protein, high energy feed
Santiago ﬂowers 80 days following seeding, which are yellow, pea-like and typically in clusters of 2-5. It has a smooth burr pod and is a proliﬁc seeder providing good persistence in a wide range of situations.
Adapted to a range of soil types from sandy loams to clays of moderate fertility. Optimal pH Ca range is 4.8-8.5 (pH water 5.6-9). Prefers mildly acid to alkaline soils (pH water > 5.6, pHCa > 4.8). Tolerant of waterlogging and moderate salinity (ECe up to 8 dS/m).
It has a greater tolerance of acidity in loamy soils but is not productive on deep sandy soils with pHwater < 5.6 (pHCa < 4.8).
Santiago is a good feed for sheep, beef cattle and horses. Can be grown in mixtures with grasses including annual ryegrass, volunteer cereals or sown cereals for grass/legume hay production, and with a range of summer growing grasses in the subtropics.
It is persistent, even under heavy grazing
It is sown between April-June. Relatively small seed, so Shallow sowing (1-2 cm) is essential with press wheels, harrows or prickle chains to improve soil-seed contact and establishment. It is suited to areas with mild growing seasons 15-25°C
On infertile soils Medics are likely to require topdressing with superphosphate and potassium. Soil testing is required to determine the need, timing and appropriate application rates.
It is better to defer grazing in the ﬁrst year until plants are well established and then only graze lightly until ﬂowering. Remove stock until medic has ﬁnished ﬂowering and producing pods, to maximise seed-set for subsequent regeneration. Paddocks should not be "crash" grazed or cut for hay in the ﬁrst year if the stand is expected to regenerate.
Major diseases are Phoma black-stem, rhizoctonia bare-patch and powdery mildew.
Santiago is sensitive as seedlings to red legged earth mite. Sensitive as mature plants to lucerne ﬂea, spotted alfalfa aphid and cowpea aphid. Sensitive to boron toxicity
You can get photosensitisation in horses, occasionally red gut in sheep, bloat in cattle.
- Recommended pH Rate: CaCl2 4.8-8.5
- Recommended Rainfall Rate: 250mm+
- Growing season rainfall 175 - 350mm
- Recommended Sow Rate:
Single species: 4 to 6kg/ha in sub tropics
Mixes : 3 to 4kg
- Days to flowering: 80 days