IN INOCULANTS Nodulaid - 17th International Nitrogen Fixation ...

17 th International Congress on Nitrogen Fixation
Fremantle, Western Australia
27 November – 1 December 2011
Session Details: Wednesday 30 November 2011
Concurrent Session 12 – PGPR & Plant Production
1100 – 1230
Author: Ivan Kennedy
SUNFix Centre for Nitrogen Fixation, University of Sydney, Australia
Presentation Title: Beneficial biofilms on plant root surfaces – achieving more sustainable crop production
Presentation Time: 1200 - 1220
Plant growth promotion (PGP) for crops by microorganisms have been recognised for some time in biological
nitrogen fixation (BNF) in legumes, shown in Germany in the late 19 th century in the face of opposition by Justus
Von Liebig. More subtle are the beneficial effects of the PGP microbes in cereals and other crops. These
involve a complex of phytohormonal effects, nutrient mobilisation, BNF and biocontrol that benefit plant growth
and overall yield (Kennedy et al. 2008). Essentially, it is possible to grow crops such as rice inoculated with
microbes forming biofilms on the surfaces of their roots while that allow significantly reduced inputs of chemical
fertilisers, seed, pesticides and water, as well as reduced harvest losses.
This presentation will focus on properties of a successful biofertiliser, BioGro ─ a commercial product invented in
Vietnam consisting of four strains (Pseudomonas, Bacillus and a yeast) inoculated to the rhizosphere of rice
seedlings. It is remarkable that BioGro contains strains selected empirically on the basis of their effectivness for
rice farmers later identified in Australia as including species recognised around the world in research laboratories
as having a strong basis for beneficial effects as biofertilisers.
As was the case about a century ago with legumes and the rhizobia that form N2-fixing nodules on their roots,
obtaining an effective outcome from applying these biofilm-forming organisms to crops in the field is challenging.
It may be important to match microbial strains with plant species but it is certainly important that inoculants of
high quality in terms of particular microbial strains in sufficient numbers (ca. 10 8 cells per g of inert carrier).
Furthermore, convincing farmers of the beneficial effects and the scale of economic benefits possible is also
important. The design of an efficient supply chain that includes quality control and delivery of economic and
environmental benefits from biofertilisers to farmers is equally challenging.
In this presentation, a strategy for simultaneously achieving environment-friendly and economic benefits being
developed in a World Bank Development Marketplace project Sustaining nitrogen-efficient rice production, will be
described. Lessons learnt from this project found to be important for implementation of new technology based
on these microbial biofilms in both developing and developed countries will be discussed.
Efficient nutrient use in rice production in Vietnam achieved using inoculant biofertilisers, I.R. Kennedy et al.,
eds. ACIAR Proceedings 130, 2008, book downloadable from www.aciar.gov.au.
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