The main constraint to the continued growth of smallholder wool producers in South Africa’s Eastern Cape is pasture quantity and quality. Pastures are generally small and do not adequately support animal production. Grazing lands have also been used for other purposes such as maize production. These practices, which involve repeated deep tillage, have led to erosion and a loss of soil structure, and ultimately abandonment of the land as non-arable.
ACIAR’s Eastern Cape Arable Lands Project (ECCAL), was born out of the need for cropped arable lands to be returned to permanent grazing. A collaboration between Murdoch University in Perth, the Western Australian state government and the South African Government, ECCAL sought to improve the food base, with legumes considered the most likely solution. The challenge was to match legume species to soil type.
Following the evaluation of both native and non-native legumes, including the potential for application in Australia to combat salinity, the perennial South African legume Lebeckia was identified as a salt-tolerant fodder for livestock. Introducing this legume to the Eastern Cape assisted in the rehabilitation of ploughed lands and increased soil fertility, along with large improvements in sheep health and production. Now grown on several Western Australian sheep farms, it is also hoped that the first Lebeckia seeds will soon be harvested commercially, ready for more widespread adoption across the marginal fringes of Australia’s pastoral belts.
Legume identification
It was initially difficult to see an obvious fit for the commercially available grazing legumes to the climate and soils of the Eastern Cape. Uncertainty surrounded whether the area was in a temperate environment with appreciable summer rain, or a cooler subtropical environment with significant winter rainfall. Local experience told the researchers that global staple legumes from temperate regions and the sub tropics were likely unsuited.
The team’s first experiments in 2006 were a series of legume explorations at three research stations spread over a 500 km north-south range. It soon became evident that several hardy, acid-tolerant species were well suited, but there was significant variation across the latitudes and altitudes. The project moved to small plot trials on community lands in 2008, where grazing was also imposed, and evolved to sites as large as 10 hectares by 2010.
The team observed some spectacular successes, with some legumes beginning to colonise and even dominate some sites despite relatively uncontrolled grazing. Lespedeza cuneata was an outstanding success in the northern mountains, while a mixture of arrowleaf clover, biserrula and common vetch produced in excess of six tonnes of biomass over winter, which provided high-value stock feed during a traditional time of animal starvation. Controlled experiments showed a doubling of weight gain for sheep grazing on legumes compared to those feeding on unimproved grassland.
Local benefits
Given that South Africa and southern Australia share a similar climate and soil composition, the ECCAL project is being shown to have local benefits. This is through the discovery of perennial legumes such as Lebeckia, which has proven adaptable to the deep and infertile sands of Western Australia. Trials have shown that Lebeckia is palatable and non-toxic to Australian sheep, will not spread like a weed, fixes nitrogen, and is not vulnerable to existing local pests or diseases. ‘Lebeckia has the potential to turn five million hectares of Australia’s marginal pastoral zone into much more productive country by providing grazing and shelter for sheep,’ said project leader Professor John Howieson. A semi-commercial harvest of seed from farms with Lebeckia trial crops began in December 2017.
Through both helping farmers in developing nations and also delivering spinoff benefits for their Australian counterparts increasingly affected by climate change, ACIAR’s ECCAL project represents a major success for Australia’s foreign aid program. Given the success of the project, Botswana has approached ACIAR to assist in developing their own proposal based around forage legumes in mixed animal-cropping systems.
