Nothing lasts forever and so it seem on the Northern rivers’ coastal floodplain where 2500 hectares of macadamia nut trees have been planted where sugar cane dominated for more than half a century – before that dairy.
On the lower Clarence, in the past two years alone, 600ha has gone under new crop with total nut area on the Northern Rivers increasing by 25 per cent, says NSW Department of Primary Industries (DPI) macadamia development officer Jeremy Bright.
While the newly arrived macadamia will capture only a fraction of the total cane area its presence is being felt for a number of reasons.
Bruce and Liz Green, Palmers Channel - former cane farmers - are on the cusp of making real return on their converted property, with trees just coming on 10 years after planting.
In the meantime, Bruce has built a business developing new macadamia country, using proven techniques pioneered by the Dorey brothers of Newrybar, north of Ballina.
At the very first there is extensive paddock preparation, using a V-shaped plough to scrape alluvial soil, enriched with chicken manure and compost, into raised beds. Contractor David Brinsmead, Murwillumbah, pioneered this technique and his unusual equipment is in high demand.
Young trees are planted in a compost of manure and woodchip and watered eight litres a week in dry times. Coastal sea breezes are an issue and young tree are staked to handle dominant winds from the south-east and north-east.
These same breezes bring coastal showers, which are a benefit to the trees. As a result of a lot of factors floodplain macadamias tend to grow less foliage on the floodplain which allows more sunlight into the canopy. Nut set, as a result, is strong.
As the name suggests, water can cover a floodplain but Mr Bright says macadamia trees survive seven to ten day inundations without loss.
Drainage channels are created with a gentle slope to allow water to drain out of the orchard in a clean clear state, as the tidal gates allow.
As grass grows between trees the runoff from a floodplain plantation is much clearer than from fallow paddocks which is a huge environmental benefit for this agricultural endeavour.
Mangrove channels which wind between paddocks offer a wind break but also harbour nut borer and fruit spotting bugs which are being fought with introduced wasps, their eggs stapled to the underside of macadamia leaves. These wasps assist in reducing the population of nut borer in both the mangrove and the macadamia trees.
Fortunately serious threats like sigastus weavill are unheard of on the flooodplain.
“The DPI tells us that distance is our friend,” said Mr Green. “At least for the moment.”
DPI’s Jeremy Brigjht says the expansion of floodplain plantations follows a workshop facilitated by NSW DPI 12 months ago.
“The participants involved have been holding monthly planning meetings, facilitated by industry and NSW DPI, relating to the complex of issues encountered when developing sensitive areas.
“The objective of the workshop and planning has been to give potential and new growers from the Clarence, Richmond or Tweed coastal areas a better understanding of what is involved in developing into productive and successful macadamia farms.
“Key to the success of developing this land is the involvement and communication with the relevant shire councils and NSW DPI Fisheries and Department of Industry – Water.
“Each workshop has been developed as a step-by-step guide to the development of a floodplain macadamia enterprise. In particular, how to work successfully within acid sulphate soil boundaries, grower responsibilities, drainage management, and other best practice techniques.”