Some things old are new again — and, according to Bob Thompson, three oldies are set to change the productivity of western NSW sub-clover pastures.
Mr Thompson, District Agronomist with NSW Agriculture at West Wyalong, is talking about three exotic forage clover species, Arrowleaf, Berseem and Persian clovers, which have been around for 30 years or more but which, until recently, remained untested in his district.
"They previously had labels put on them — like only being useful for saline or acid soils or as dairy pastures," he said.
"However, in 1995 they were included in GRDC-supported trials of forage clover species, and three of the exotics have proven surprisingly productive, long-lived and persistent on the red-brown earth soil at Weethalle and on the grey clay at Bardeman."
Forage clovers extend grazing phase
Mr Thompson said quick-maturing sub-clovers had been the backbone of western pastures.
However, they generally dried off during the first week in October, denying weaned lambs and about-to-be-mated ewes access to green feed.
Consequently farmers were looking for additional species to extend the grazing phase of sub-clover pastures, particularly where lucerne was not a suitable pasture companion.
"The key to the exotics' local success is in producing high levels of hard seed and an extensive root system, and they do not appear to compete directly with sub-clover," Mr Thompson said.
"Sub-clovers provide the autumn and early spring grazing and the three exotics late spring and early summer grazing.
"They have also greatly reduced summer weed growth and this saves cultivations and herbicides, and reduces livestock health problems."
He says features of the three exotics include:
- Arrowleaf clover — Zulu appears to be the outstanding companion species to date. About 9 tonnes of seed was sown in 1998 and 25 tonnes this year; it has established well on most soil types and is providing an additional grazing period of 6-15 weeks over pure sub-clover pastures.
- Berseem clover has given the best early growth and best growth for hay production on the grey clays
and will augment long-term sub-clover pastures that are frequently flooded and waterlogged. It responds to high levels of molybdenum and provides a lower risk of cattle becoming bloated. • Persian clovers have grown and persisted well on red and grey soils, provided extended grazing over pure sub-clover swards and have produced extra feed in wet years. Persians are very tolerant of clover scorch and root rot, and of waterlogging. They have replaced Trikkala in Clare sub-clover mixes on grey clay soils.
The Prolific variety is the most widely sown although it is hoped that local farmers will also evaluate Nitro, Laser and Leeton Persian clovers. This year about 10 tonnes of Prolific and Nitro seed (combined) have been sown.
Resowing best bet
When resowing pastures, Mr Thompson advises farmers to add 1 kg/ha of their newly chosen exotic clover to a 5 kg/ha mix of two sub-clover varieties.
"Too often farmers sow a little bit of a lot of species and varieties and end up with a thin pasture containing few useful plants, a lot of weeds and, due to the species mix, probably no herbicide options," he said.
Contact: Mr Bob Thompson 02 6972 2244