Phytoextraction of phosphorus from Australian dairy pasture soils to reduce environmental loss

摘要

The loss of phosphorus (P) from land used for primary production to the environment is of considerable interest for the research and policy fields. Phytoextraction of pasture soil P through management practices such as reducing or omitting P fertiliser application may reduce concentrations and ultimately losses to the environment in surface runoff. The rate of soil P decline when phytoextracted by intensive pasture systems is not known, but preliminary results suggest that the initial soil extractable P concentration, soil buffering properties, P removal rate, P fertiliser rate and time may affect the rate of decline. We investigated the effect of these factors on the rate of P decline on six soils in north-west Tasmania. Olsen, Colwell and CaCl2 Pextractions are being used as agronomic (Olsen and Colwell P) and environmental (CaCl2) measures of soil P. It is hypothesized that soil characteristics are the main driver behind the rate of P decline and the effects of various properties are being examined.