Exploring efficient techniques to decrease phosphorus levels in previously farmed land to promote the revival of indigenous grassland

Abstract

Restoration of native grasslands is challenging due to high soil phosphorus levels. Cultivation of plants with high phosphorus (P) absorption is an optimal solution to remove and decrease P from the soil. It has been demonstrated that native grassland taxa (species) of the genus Ptilotus have significant P-uptake. In a glasshouse study, Ptilotus macrocephalus and Ptilotus polystachyus were tested for their ability to reduce the amount of soil phosphorus that was readily available. Lupinus albus, a third species with a reputation for high phosphorus uptake, served as a comparison species, and a further treatment included Phoslock®, a soil additive that could bind soil phosphorus into insoluble forms. The findings revealed that phosphorus in the soil was absorbed at a high level via Ptilotus macrocephalus and Ptilotus polystachyus showed a maximum reduction of P (-2.58 and -2.55 ppm). It is argued that several years of planting and harvesting these plants will offer a workable method for lowering soil phosphorus levels. However, this only happened at high concentrations of 1500 g/m2 and when soil phosphorus concentrations were very high. Despite, the Phoslock®'s effectiveness in lowering soil-accessible phosphorus. At concentrations often observed in former agriculture paddocks, it proved less effective. The study's findings have improved our existing comprehension of reclaiming abandoned grassland.