Managing Earthworms as a Resource in Australian Pastures - Earthworm Ecology - page 250

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Managing Earthworms as a
Resource in Australian
Pastures

Geoff H. Baker

CSIRO Entomology, Canberra, Australia

CONTENTS

Introduction....................................................................................................................................263
The Earthworm Fauna in Australia...............................................................................................264
Effects of Earthworms on Soil Properties and Plant Productivity in Australia...........................267
Effects of Agricultural Management Practices on Earthworms....................................................270
Introductions of Earthworm Taxa to New Areas...........................................................................275
The Potential for Introducing New Earthworm Species into Australia........................................277
Earthworms in Pastures in Northern Australia..............................................................................277
Earthworms as Indicators of the Sustainability of Agriculture:
From the FarmerÔs Perspective..................................................................................................278
Conclusions....................................................................................................................................278
References......................................................................................................................................279

INTRODUCTION

Earthworms are well known for their abilities to improve soil structure, fertility, and agricultural
production (Lee 1985; Edwards and Bohlen 1996). For example, research in New Zealand has
shown that introduction of earthworms to pastures that are lacking them can enhance pasture
production by up to 25% in the long term (Stockdill 1982). This improvement in grassland
production in New Zealand resulted especially from the introduced earthworms feeding on a thick
mat of dead organic matter that had accumulated at the soil surface. The breakdown of this organic
mat returned nutrients to the soil and enhanced water infiltration. Comparable research in northern
Tasmania (Temple-Smith 1991) and on-farm applications (D. Ford and B. Farquar personal com-
munication 1992) have also demonstrated that similar increases in pasture production can be
achieved in these regions using the same technologies as those used in New Zealand (inoculating
pastures by spreading sods of soil containing earthworms). In addition, significant increases in
plant production have resulted from introductions of earthworms into agricultural soils in several
other countries (e.g., Ireland, Netherlands, United States) (Baker 1998a).
Agricultural soils in southern mainland Australia are generally poor in structure and fertility.
The work in New Zealand stimulated a flurry of research in the late 1980s and early 1990s aimed
at improving the management of earthworms as a resource in agricultural soils in southeastern
Australia (Temple-Smith and Pinkard 1996). Several factors further encouraged this expansion in
earthworm research. Increased on-farm costs (fuel, labor, machinery), reduced values of agricultural

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