Australia
March 16, 2020
DAFWA team with SF Rouse at Manjimup, Western Australia
A five-year joint venture between the Department of Agriculture and Food WA (DAFWA) and Seed Force via a $700K investment, has delivered eight new sub-clover varieties to Australian livestock producers.
The new varieties cover all three sub-species, catering for differing soil types and annual average rainfall ranges from 325-1000mm. Most are now commercial with some in limited supply at this stage.
Varietal gains include improved seed yield and resistance to major sub-clover pests and diseases, to deliver higher forage yields and longer persistence.
Ultimately, sub-clover performance is a numbers game. Put simply, if sown seed can deliver plants that produce more seed, this can then produce more seedlings. If those seedlings have improved resistance to pests and disease, more plants will survive to produce greater feed, especially in the autumn/winter period.
Manjimup sub-clover trial site
The new varieties from the Seed Force/DAFWA Joint Venture have all been bred with this in mind. They have been selected after thorough multi-location, three-year replicated trials to evaluate a final selection of 20-24 improved breeding lines of each sub-species compared with existing commercial varieties.
Subterranean clover (sub-clover) is a pasture legume native to the Mediterranean basin, the western Atlantic coast of Europe and west Asia. This makes it well adapted to other areas of the world with similar climates, such as southern Australia, where it is now a key part of our sustainable mixed grass and legume-based pasture systems.
Plant features
- Annual life cycle: Sub-clover is an annual legume, which germinates in autumn and completes seed production in spring/early summer (timing depends on the cultivar).
- Natural re-seeding: Sub-clover regenerates naturally each year from seed set in previous years, without the need for re-sowing.
- Easy-care grazing: Sub-clover is very grazing tolerant, due to its prostrate growth habit, flowers close to the ground and burial of its seed-containing burrs.
- Persistence over seasons: Sub-clover is a reliable seed producer. Most seeds germinate the following autumn, however some seeds remain dormant as ‘hard seeds’ (the proportion depends on cultivar), which ‘soften’ over subsequent summers for germination. This results in natural re-seeding even after poor seasons for seed production.
- High feed quality: Green sub-clover has similar feed quality characteristics to lucerne and white clover. It has high energy and provides protein to meet all livestock minimum requirements.
- Improved soil fertility: Sub-clover fixes nitrogen, with the aid of Rhizobium bacteria, for its own growth and supplies N to other grasses and herbs in the pasture. It also provides N in the soil for crops and other plants in following years. In general, it will produce around 20kg N per tonne of dry matter produced.
Subspecies and soil type suitability
Sub-clover consists of three subspecies, adapted to different soils.
- ssp. subterraneum is adapted to well-drained, moderately acid (pHCa 4.5 – 6.5) soils. Most cultivars belong to this group. This type actively buries its burrs. Seed Force has released four new subterraneums, each with seedling resistance to red-legged earth mite and suited to varying growing season length with SF Tammin (88 days to flower), SF Forbes (101 DTF), SF Narrikup (126 DTF), and SF Rosabrook (140 DTF).
- ssp. yanninicum is also suited to moderately acid (pHCa 4.5 – 6.5) soils, and is well adapted to waterlogged or poorly drained soils and to soils that hold their moisture. This type also actively buries its burrs.Seed Force has released two new yanninicums with improved seed yield and resistance to clover scorch. They are suited to mid to late growing season lengths with SF Yanco (121 DTF), and SF Rouse (131 DTF).
- ssp. brachycalycinum is best suited to well-drained, neutral-alkaline (pHCa 6.0 – 8.0) soils. This type has long, thin burr stalks and seeks out cracks or stones to develop its burrs, rather than actively burying them.Seed Force has released two new brachycalycinums with improved seed yield and resistance to mildew. They are suited to mid to late growing season lengths with SF Tarlee (130 DTF) and SF Antillo (138 DTF).
Sub-clover PBR trial at Shenton Park, Western Australia
Use of sub-clovers in southern Australia
Sub-clover is well adapted to the Mediterranean-type climate (mild, wet winters and hot, dry summers) of southern Australia, where it has been sown over an estimated 29 million hectares. A range of cultivars with differing flowering times, enables sub-clovers to be grown in environments with annual average rainfall ranging from 275 mm to 1,200 mm.
In high rainfall areas sub-clover is generally sown in permanent pastures, often with perennial grasses, while in low and medium rainfall areas it is often grown in rotation with crops. It is grazed by both sheep and cattle. Its prostrate growth habit makes it particularly well suited to prolonged heavy grazing by sheep. Excess pasture in spring is often cut for conserved fodder (hay or silage), although more erect species are better suited to this. Dry pasture residues over summer are grazed.
You should select the correct sub-species (subterranean, yanninicum, brachycalycinum or a mix) for the different soil types in your paddock, then select the most appropriate variety for your rainfall.
It is often advisable to mix 2-3 varieties to cover the fact that seasons and rainfall can vary by year.
For example, a mix of SF Narrikup and SF Rosabrook could be used in 600-650 mm rainfall to cover higher or lower rainfall years, or a mix of SF Rouse and SF Rosabrook could be used where parts of a paddock can become waterlogged in some years but rainfall is reliable.
Seed Force has a sub-clover selection chart available showing all varieties (past and current) in Australia, allowing for easy comparison and suitability for specific rainfall, season length and soil types.
For more information contact your local Seed Force territory manager.
Topics
Species
