NSW farmers turn flood debris to mulch

Still reeling from the aftermath of devastating floods, NSW Northern Rivers farmers are turning muddy debris into mulch that will help grow their crops.

Rural Aid, a charity helping farmers, in partnership with biotechnology firm Multikraft Probiotic Solutions, has sprayed nearly 40,000 litres of microbial product by helicopter onto 33 farms in northern NSW.

It quickly decomposes flood debris into mulch.

Bill Hoare, Multikraft's Chief Innovation Officer, explained that anaerobic microbes embedded in the solution re-activate the soil by injecting a dose of oxygen in order for photosynthesis to take place for tree and crop growth.

More than 1820 hectares were sprayed across the region for free.

Wardell macadamia grower Robbie Commens said his orchard near Lismore was completely inundated.

"We had a metre and half of water over the top of all our trees. That first flood was catastrophic," he said on Wednesday.

"We're at the bottom of the hill from Lismore and we copped all of that water.

"We had two huge events in four weeks," he said.

The scientific innovation has helped lift the Northern Rivers farming community's spirit.

"We're very hopeful it will be a good shot in the arm for the trees ... and as farmers... it has made us feel valued and respected ".

Rural Aid CEO John Warlters said the project was a timely solution for flood-affected farmers.

"Farmers have responded to this microbial spraying project with tears of joy, buoyed at the prospect of seeing their farms recover from the floods more quickly," he said.

At least 10 people died from the devastating floods across the Northern Rivers and western Sydney, with Lismore hit the hardest under the onslaught of relentless rain during February and March.

Meanwhile, Lismore City Council has announced a free concert next month "to celebrate the resilience and lift the spirits of the Lismore Community".

Grinspoon, Paul Kelly and Dan Kelly, Jon Stevens, Lime Cordiale, Sheppard, Daryl Braithwaite, Darlinghurst and The Buckleys will perform at the Lismore Showgrounds on May 15.

Tickets will be free for residents living in 2480, 2471 and 2472 postcode areas and are available from Wednesday.