IMPROVING THE PRODUCTIVITY OF SALINE DISCHARGE AREAS - AN ASSESSMENT OF THE POTENTIAL USE OF SALTBUSH IN THE MURRAY-DARLING BASIN

Results of field trials testing the growth of Atriplex species on sali ne soils in Western Australia have been used with the PLANTGRO model t o predict the success of 6 Atriplex species on 6 salinised soil types at 6 localities in the Murray-Darling Basin. The model's predictions t hat the productivity of all species would be severely limited on crack ing clay soils due to poor aeration were tested by examining data from field trials. It was concluded that saltbush production will be very poor on heavy clay soils. Field trial data suggest that these limitati ons will be exacerbated by the interaction of aeration and soil salini ty factors at mean salinities (EC(e)) > 10 dS/m, and the planting of A triplex on these sites is not recommended. Better results are expected on some duplex and gradational soils where larger sand fractions in t he A horizon improve soil aeration characteristics. However, the model predicts that productivity will, at best, be low to moderate at all t he Murray-Darling Basin sites examined.