Ground Cover North : Ground Cover 062 June-July 2006 - North
BY TRENT CARSLAKE n The ongoing challenge to turn a dollar from landscapes affected by salinity continues to turn up novel ideas; the latest being a proposal for a wheatbelt seaweed industry. The idea is being promoted in WA by oceanographer Rob Cordover, who believes the state’s two million hectares of salt- affected farmland could support a food- quality seaweed industry, although more needs to be learned about the appropriate agronomy. This will be the focus of planned trials on a northern wheatbelt farm. Mr Cordover became interested in the commercial potential of saline groundwater several years ago and initially raised the idea of growing prawns or fish, but failed to stir much enthusiasm among farmers. “The infrastructure needed was too elaborate and they wanted to stick with what they knew, which is cropping,” Mr Cordover says. This led to him to consider seaweed, which he says could be more manageable, plus there is an established market for seaweed gels and edible seaweeds. Mr Cordover says seaweed also has the attraction of being, in effect, a perennial: “The initial crop is introduced from a cutting that grows into a harvestable crop. At harvest time you simply leave a small portion of seaweed behind, from which the next crop grows.” He says seaweed is comparatively easy to grow and can be harvested and baled like hay. To learn more about the agronomy of seaweed production, the Morawa Farm Improvement Group is planning to run trials on the property of Rod Madden. Mr Madden has installed a deep drainage system that feeds into evaporation basins. “We tested the water in Rod’s evaporation basin and it appears to be suitable for seaweed growth,” says Mr Cordover. Mr Cordover says worldwide demand for seaweed gels and the market for edible seaweeds in China, Japan and Korea is worth billions of dollars, and he can see no reason why Australia couldn’t tap into that demand. The initial work is concentrating on a seaweed species found in Australia that yields a high-quality marine gel and is already used in the food and biomedical industries. Most of this seaweed currently comes from Chile where it is grown in the ocean. “However, growing seaweed in the ocean leaves you a lot more exposed to the elements, with currents, tides and schools of fish easily able to wipe out your crop,” he says. Mr Cordover believes farm-based seaweed production in saline ponds could earn the equivalent of $16,000 a hectare per year, given that growth rates should allow four crops a year. However, he cautions that not all saline groundwater is suitable and much depends on the local geology and whether the groundwater contains toxic chemicals. Kevin Goss, chief executive officer of the Cooperative Research Centre for Plant- based Management of Dryland Salinity, says research into the productive use of salty water where groundwater pumping or drainage is feasible is important for finding economic solutions to the issue. “With our best efforts we can limit the increase in the future amount of land degraded by salinity, but we also need to learn how to live with salinity,” Mr Goss says. More information: Rob Cordover, 03 6239 6784, firstname.lastname@example.org JUNE -- JULY 2006 GROUND COVER 25 Salinity Salinity quest checks out seaweed Growing edible seaweed for the established Asian market could be a profitable option for some of WA's two million hectares of salt-affected farmland Seven kilometres of deep drainage feeds saline groundwater -- suitable for the cultivation of seaweed -- into this evaporation pond at Rod Madden's Morawa farm. Morawa grower Rod Madden shows members of the Morawa Farm Improvement Group his evaporation pond, which will be used to test the feasibility of seaweed production. PHOTOS: TRENT CARSLAKE SOUTH AMERICAN SOLUTION FOR SALT-AFFECTED SOILS BY REBECCA THYER n Finding a perennial pasture legume that tolerates both salinity and waterlogging and is an economical option for mixed farmers has led PhD student Natasha Teakle to a South American lotus. The GRDC-funded scholar is enrolled at the School of Plant Biology at the University of WA, with supervisors Dr Tim Colmer and Dr Daniel Real. Her work is also supported by the Cooperative Research Centre for Plant-based Management of Dryland Salinity and the AW Howard Trust. Ms Teakle says salinity is one of the biggest threats facing Australian farming systems’ sustainability. “From a physiological and scientific point of view, improving salt tolerance in crops or pastures is a challenge.” Although returning to perennial plant systems is the best approach for combating salinity, economic factors generally rule out planting perennials to the extent needed to have an impact. “A perennial pasture that tolerates high salt concentrations and provides fodder to livestock could create a profitable option to lowering the watertable and combating salinity,” she says. Ms Teakle’s work concentrates on a species of lotus (Lotus glaber), which grows on the waterlogged, saline flats of Argentina. Her project aims to identify and characterise the physiological and molecular basis underlying L. glaber’s salt tolerance, to help produce new pasture options. How L. glaber tolerates salinity and waterlogging is not well understood and species variation has not been characterised. By identifying genes for these traits, researchers and plant breeders will be able to quickly screen plants, speeding up the development of new salt-tolerant varieties. Collaboration with world leaders in plant physiology, molecular biology and plant breeding is an important part of the project. Ms Teakle is working with Professor Tim Flowers, from Sussex University (UK), on L. glaber’s physiology. Work to isolate the gene or genes responsible for controlling salt tolerance in L. glaber has led Ms Teakle to Dr Anna Amtmann at Glasgow University. Ms Teakle is realistic about past research. “There’s been very little success because salt tolerance is such a complicated genetic trait. And each farm and season is so variable that it can be hard to manage, but salinity is a major issue that needs to continue to be addressed.” Natasha Teakle: investigating the salt tolerance of a South American lotus as part of the quest to develop new salt-tolerant pasture varieties.
Ground Cover 063 August 2006 - North
Ground Cover 061 April-May 2006 - North