Land & Water Australia
NEWS RELEASE
1st October 2008
Fertiliser is a key factor in
biodiversity management
Although fertilisers have boosted the production of improved pasture species this has
been at the expense of drought tolerant perennial native plants.
According to researcher Sue McIntyre, the environmental cost of fertiliser use is
expressed as a decline in the diversity of native pasture species and the loss of
native grasses.
She will be a speaker at the Veg Futures Conference in Toowoomba this month.
Veg Futures is a about practical aspects of vegetation management in production
landscapes presented by Greening Australia and Land & Water Australia.
It is not suggested that farmers, particularly grain producers, ignore the advantages
of fertilisers but being aware of the effects could influence their management,
particularly where the advantages of drought-tolerant native plants are valued.
“For a long time we have blamed livestock grazing for having impacts on biodiversity
and ignored the effects of fertiliser use” Dr McIntyre said.
“While it is true that overgrazing can have serious impacts on the soil and reduce
habitat quality for plants, birds and animals, the effects of fertiliser use are far more
permanent.
"Because many Australian native plants and animals are adapted to drought and low
fertility soils, they fail miserably to persist when superphosphate and exotic legumes
are added.
"Fertiliser inputs mean that grazing pressure needs to be increased to gain returns.
Pastures tend to lapse towards annual dominance under these conditions and
erosion risks increase. Eucalypts stop regenerating as the seedlings are either
grazed out, or out-competed by fast growing exotic pasture, so tree decline and
habitat loss become part of the picture as well.
"Reducing or stopping fertiliser use enables drought tolerant native grasses to
persist. Peaks of production may be lower, but ground cover is better and growth
response to rainfall in summer gives useful production benefits.”
The Veg Futures 08 Conference will be held in Toowoomba from October 20 to 23 at the
Empire Theatre (media contact is Samantha Morris on 0421 709 519). It will address carbon
markets, revegetation, the role of native vegetation in agriculture, and other issues. Further
information can be obtained from Kirsti Sampson of Greening Australia Ph (02)6202 1600, or
Sue McIntyre can be contacted at CSIRO Sustainable Ecosystems on (02) 6242 1604.
NEWS 
