Packaging local bacteria together with the seeds of native plants could replenish the vegetation of dryland ecosystems, according to a new study led by researchers from the University of New South Wales (UNSW Sydney).
The study, published in the Journal of Applied Ecology, noted that one of the potential factors restricting plant establishment in degraded soils is the low abundance and diversity of native soil micro-organisms.
The research team therefore investigated whether returning indigenous bacteria and cyanobacteria consortia to degraded dryland could improve seedling and survival of native plants.
After combing native bacteria together with the soil that contained the seeds of native plants — a spinifex and the fire wattle (an acacia) , the research team found the wattle seed germination was improved by around 50 percent, and the germination rate of spinifex also improved by around 20 percent.
Micro-organisms use different mechanisms to improve plant growth, both directly and indirectly. For example, they contribute to moisture infiltration and retention in soils for plants, control soil erosion and enhance nutrient availability to plants, said Frederick Dadzie, lead author and PhD candidate of UNSW Sydney.
“We found that micro-organisms were very beneficial for getting the plants established, especially at the earlier stages when they were just seeds making it to a seedling. After that, the relationship was less clear,” he noted.
In Dadzie’s view, though the presence of indigenous bacteria after germination did not influence plant survival for better or worse, the finding that microbes improve germination in degraded habitats is still good news for ecosystem restoration.
“And what’s better: this is a simple, two-step process that can be scaled up for restoring dryland ecosystems. First, combining the seeds and soil into pellets, and second, inoculating those pellets with the microbes,” he added. ■