More shots at a moving target
The recent spectacular adoption of one new pasture variety by Australian farmers illustrates broad-scale changes occurring in pasture development for contemporary farming systems, according to Mike Ewing. Pasture breeding and selection in Australia are expanding from the subclovers and annual medics to meet new farming systems and agronomic problems.
Speaking at the Australian Plant Breeding Conference in Adelaide, Dr Ewing said Cadiz serradella had been released for seed production only in 1996 but this year an estimated 250,000 hectares would be sown to it across four states.
Dr Ewing, whose work at the Cooperative Research Centre for Legumes in Mediterranean Agriculture is supported by growers through the GRDC, said Cadiz would have been poorly suited to past farming systems which were characterised by the pasture 'ley' approach, which favoured regenerating clovers and medics.
Suited to phase farming
Now, however, many graingrowers were phase farming and needed a pasture which was soft-seeded and easily sown at high densities. (Phase farming is rotation of crops and pastures in blocks of years.)
He said Cadiz had these attributes and was an important new tool for producers with phase rotations, particularly those farming sandy and often infertile soils.
Other trendsDr Ewing said examples of changing pasture use in cropping areas included:
- Persian and balansa clovers which were being widely grown in waterlogged and mildly saline conditions
- serradella cultivars for acid and infertile soils
- newly commercialised species such as Biserrula from the Mediterranean region which could be sown as mixtures with older subclover and medic varieties
- Caprera crimson clover, suited to phase-farming systems in areas of moderate to high fertility and higher rainfall. Because it was an erect, aerial seeding species, its seed was also easy to harvest.