Rhizobial Carriers

Evaluating Alternative Rhizobial Carriers

Project Funder: Soil CRC

Project Lead Organisation/Researcher: Griffith University, Professor Chengrong Chen

Project Duration: June 2022 – May 2025


The aim of this project is to develop the manufacturing protocol for the production of novel inoculants (both inorganic and organic-based) and to evaluate their shelf life and effectiveness in nodulation, N-fixation and crop growth performance across key agricultural regions, climatic zones, and soil types in Australia.

Description and background

Rhizobium inoculation has contributed significantly to the supply of nitrogen in most farming systems, but the availability of peat – the most widely used carrier for Rhizobium – is a non-renewable resource and is becoming increasingly scarce in many regions. As well as this, the existing inoculation techniques often result in low survival rates of rhizobia on the seed and in the soil due to desiccation and heat, and this limits the nitrogen-fixing efficacy of the rhizobial inoculants.

This project will employ a suite of advanced analytical approaches to evaluate the suitability of locally available, low cost organic and inorganic materials, biochars produced from different feed stocks and pyrolysis conditions, and emerging biopolymers as alternative carriers for effectively delivering rhizobia.

The project will also address the issue of capturing and retaining moisture to improve prolonged survival of rhizobial inoculants. There will be new knowledge on cost-effective alternative carriers for formulation of rhizobial inoculants to improve legume nitrogen-fixation and soil productivity in Australian farming systems. This project will evaluate locally available and newly emerging alternative carriers to provide practical solutions to the desiccation issue through close collaboration with industry and farmer groups.


This project is a partnership between Soil CRC, The University of Newcastle, Griffith University, Central West Farming Systems, Australian Organic Recycling Organisation, Herbert Cane Productivity Services Ltd, Burdekin Productivity Services Ltd, Western Australian No-Tillage Farmers Association (WANTFA).