Many years of testing a range of groundcovers for use in NSW North Coast macadamia orchards will culminate with the release of a smothergrass guide at a field day next week.

The day will be held at Liz Broad’s Farm "Seachange" on Cowlong Road at McLean’s Ridges on Wednesday 9 July starting at 9.30am.

Smothergrass was found to be the most suitable species for macadamia orchard floors after several years of research carried out by NSW Department of Primary Industries in a project funded by the Australian Macadamia Industry and Horticulture Australia.

NSW DPI Industry Leader at Alstonville, Mark Hickey, said the guide brings together the best available information on the establishment and ongoing management of smothergrass, a covercrop which reduces erosion in an orchard by up to 99 per cent and allows for nuts to be machine harvested off the ground.

"Growers share their experiences in this guide on the practices they have found to be the most efficient for successful smothergrass establishment and management," he said.

"By combining the collective knowledge of growers and over 20 years of research this guide provides the most up-to-date information available on topics such as how to ensure efficient harvesting is achieved from smothergrass."

Mr Hickey said the project consulted widely with industry, developing a list of essential criteria for groundcovers.

"The desirable species had to have good shade tolerance, be low growing, requiring minimal mowing, be suited to harvest off and be able to withstand regular orchard traffic," he said

"In the process of testing several species, the benefits of good groundcovers such as smothergrass became very clear. These included reduced soil erosion, reduced water run-off volume and speed, reduced nutrient losses and improved soil structure.

"In addition to the benefits to the soil, fewer nuts were lost in run-off water during heavy rain, and less nuts were trapped between exposed roots. Growers were often surprised at the extent of loss of nuts in run-off water, and this was one of the unexpected benefits of smothergrass"  

The smothergrass field day will include presentations from industry consultants and NSW DPI researchers, shared experiences of growers who were involved in the project, and an orchard walk. Growers attending the field day can place an order for a free copy of the guide.

For more information, please contact Mark Hickey, Industry Leader at NSW DPI Alstonville on 02 66262436 or 0427401474.

Further reading

Reducing erosion and other soil degradation in macadamia orchards (Agnote DPI 331)

Sweet smothergrass - a perennial groundcover for subtropical orchards (Agnote DPI 382)

Media contact: Phil Bevan 0429 458 053