The mission: to unearth the secrets of ground control

Dr Greg Bender

By Dr Greg Bender, program consultant, Soil Biology Initiative, 02 6248 0165,

Whenever we ask growers to list their top priorities for research, soil biology almost always appears high on the list.

The enthusiasm for soil biology is shared by researchers who have been trying to put the pieces together in what has been a difficult science.

And while the science has been progressing, various philosophies, products and practices have emerged in the industry, often with little scientific basis and even less solid field data to support any claims.

It is into this lively zoo of scientific (and not so scientific) activity that the GRDC has launched its $10 million investment in soil biology research.

Most people have heard of the contributions made by Rhizobium bacteria (legume inoculants) as a nitrogen input through legume crops and pastures. The cumulative benefits to agriculture, measured as nitrogen fertiliser equivalents, since legume inoculants were first used can be measured in billions of dollars.

In more recent times the industry has become aware of yield losses caused by root diseases such as take-all, Rhizoctonia, nematodes, and crown rot. Root diseases can account for lost yield measured in hundreds of millions of dollars a year. Therefore, simply reducing the impact of root diseases alone would be an excellent return on investment for the Soil Biology Initiative.

The CSIRO, SARDI, and C-Qentec have joined forces to develop and market a root-disease testing service, with their PreDicta B® soil tests based on the latest molecular technology. The challenge now is to develop additional tests so that growers can measure soil health as a part of their overall farm management.

An important realisation has been that soil health for the living part of the soil means that we must fix physical and chemical problems such as waterlogging, salinity, acidity, and toxicity. So a definition of what makes a healthy soil should include not only biology but physics and chemistry.

The GRDC’s Soil Biology Initiative began in July 2001. From the beginning it was immediately apparent that we only had a few pieces in the jigsaw puzzle. Since then we have been carefully assembling a research program to simultaneously deliver on two fronts.

The first is to come up with new products and management practices that will make a difference on-farm for growers. Good progress has been made and will be detailed in a follow-up article later in 2004.

And while trying to make a difference on-farm in the short term, we have not forgotten the other research front, which is the need for innovative basic research and a few breakthroughs to underpin our efforts in the paddock.

In this special feature in Ground Cover, we have assembled research snapshots from the Soil Biology Program to give a taste of some of the leading edge research in progress.

Perhaps the most exciting prospect for GRDC and the researchers involved in the program is that management of soil biota has real potential to make a big difference on farm.

And most importantly for growers, these benefits will be cost effective and will improve sustainability.