A new technology developed by WA-based Murdoch University researcher Sofie De Meyer has received a $30,000 grant from the WA government to help isolate bacteria in the root nodules of legumes.
MALDI-ID is a novel technique, which identifies directly the most beneficial bacteria for farmers’ crops, using mass spectrometry to get a fast readout.
Within minutes, farmers know whether they need to buy root nodule bacteria to inoculate their plants.
Dr De Meyer said her method is faster and cheaper than traditional techniques because it can be applied directly to the root nodules and does not require the isolation of the bacteria.
“The key in having the correct bacteria in these root nodules defines what yield and what amount of nitrogen that can be fixed, so it’s really crucial for the farmer to know whether they have the correct rhizobium, and whether it’s working as it should be working,” Dr De Meyer said.
“What we actually do is we generate a fingerprint of that root nodule and then we compare that fingerprint with a database we have, which has all the current rhizobia inoculants in it.
“It means that they will need less fertiliser because all that nitrogen from the legume is put into the ground and it’s available for the wheat and barley crop.
“So they’re saving time and they’re saving money.”
The agriculture industry in Australia uses 5.3 million tonnes of fertiliser each year to both maintain and increase plant growth.
Legume roots produce a major fertiliser nutrient naturally.
Nitrogen is produced in nodules that form on the roots of legumes by the rhizobium bacteria contained inside.
The bacteria take nitrogen from the air and convert it to ammonia, which is a fertiliser for the plant.
Pasture and pulse legumes are a unique group of plants that can transform atmospheric nitrogen into ammonia (plant nitrogen fertiliser) using root nodule bacteria called rhizobia.
The ammonia is then converted into organic compounds by the plant and used for growth.
The amount of nitrogen fixed by legumes is strongly linked to productivity and can yield up to 300 kilograms a hectare per year under good growing conditions.
But none of the agricultural legumes used in Australia are native and hence these rhizobia are not naturally present in the soils.
Therefore, producers rely on commercial inoculant products to provide the correct rhizobia and sufficient quantity of rhizobia to their seed while sowing.
The MALDI-ID method uses a mass spectrometry machine and genetic sequencing of protein markers to detect and identify the different strains and their unique fingerprints.
Dr De Meyer will use her scholarship money to visit major inoculant manufacturing companies and laboratories in South America, the United States and Canada.