Shaping and watering a compost pile on one of the participating farms .
Turning weeds into compost
NQ Dry Tropics partnered with Burdekin Shire Council and lower Burdekin cane growers to turn aquatic weeds into a nutrient-rich compost benefiting soil health on local farms .
Five farmers joined the trial , each getting about 150 cubic metres of water hyacinth removed from local creeks . Guided by Agroecologist David Hardwick , they created the compost by mixing the weeds with green waste and compost inoculum ( a blend of bacteria ) to help break down the piles .
Waterways , Wetlands and Coasts Team Leader Scott Fry said removing weeds from creeks , rather than spraying them , enhanced wildlife habitat , improved water quality to the Great Barrier Reef , and protected infrastructure from flood .
“ Aquatic weeds are full of nitrogen , and their root systems trap sediment , so as they decompose and sink , oxygen is drawn from the water and nutrients are re-released , which reduces habitat for native fish ,” Scott said .
“ The sediment attached to the roots silts up the creek , filling it up from the bottom and reducing its water-holding capacity , increasing the likelihood of flood damage to surrounding infrastructure and properties .
“ During heavy rains , these nutrients and sediments are flushed into the Great Barrier Reef lagoon , where they impact seagrasses and corals .”
Clare grower Heath Salter said he hoped the compost would save him money by reducing outlay on fertiliser , water and electricity .
Standing on a pile of compost are ( from left ) Clare cane grower Heath Salter , agroecologist David Hardwick , and Waterways , Wetlands and Coasts Team Leader Scott Fry .
“ Hopefully the compost will increase the soil ’ s capacity to hold water and nutrients and grow better cane with the least possible inputs ,” he said .
The Reducing Fine Sediment By Maintaining And Restoring Burdekin Stream Banks And Coastal Wetlands project is funded by the Queensland Government ’ s Natural Resources Investment Program .
2021-2022 – NQ DRY TROPICS YEAR IN REVIEW PAGE 23