After 20 years spent establishing their orchard, Jo and Andrew Horsburgh are excited about the emerging opportunities for the NZ walnut industry. Photo: Annette Scott
New Zealand is crying out for more walnuts, posing an opportunity for an exciting emerging industry.
The practicalities and benefits of growing walnuts were shared by the NZ Walnut Industry Group (NZWIG) at a field day hosted by Andrew and Jo Horsburgh on their Tunlaw Farm at West Melton, Canterbury.
Very much a family affair, the Horsburghs have been 20 years establishing their 47-hectare walnut orchard developed from barley grass, planting 18 kilometres of shelter, 4000 walnut trees and installing 64 kilometres of underground irrigation.
“Walnuts are an emerging industry, viable, sustainable, with good market prospects and very low carbon emissions,” grower and Walnut NZ co-op chair Andrew Horsburgh said.
“At the moment we are getting two tonnes to the hectare, but demand is there and we have aspirations to get four tonnes.”
“Walnuts are yet to be proven in NZ, but we are getting there.
“At this stage the typical NZ orchard is small by international standards, but we expect to see more large orchards as the industry continues to develop.
“As growers we are learning off each other, we have learnt some things the hard way, like we pruned wrong, there are plenty of people to tell you what not to do.”
Walnut orchards have low inputs compared to many land-uses, and low emissions to the environment in terms of greenhouse gas (GHG) emissions and nutrient losses.
GHG emissions from walnut orchards are in the order of 1.2 to 2-6 tonnes of carbon dioxide (CO2) equivalents per hectare a year.
This is similar to other low nitrogen input perennial crops such as grapes or apples, but typically lower than the annual arable or vegetable crop rotations, and much lower than moderately or intensively farmed livestock.
“We don’t have figures for sure yet, because the walnut industry is new, but based on the data we are using, it is reasonable to assume that walnut orchards will remove more CO2 than they emit,” Plant and Food researcher Steve Thomas said.
Consumer demand for the nutritional attributes of walnuts is positive, with most of the NZ walnut harvest absorbed in the local market as kernel pieces, in shell, or as products such as walnut oil, flour, dukkah and walnut paste.
“I see a real future for walnut growing in NZ, the NZ market is crying out for more walnuts,” NZWIG chair Dave Malcolm said.
“There is export inquiry too, so the challenge is to produce more.
“Whether a dairy, sheep or beef farmer looking to diversify or an aspiring lifestyler, there’s an exciting opportunity in walnuts.
“If we can get six tonnes off new varieties at $5 a kilogram it’s going to be a highly profitable industry just waiting to get loose.”
The one catch is you need to be in for the long-term, as walnuts take several years to come into bearing.
“You can expect small harvests from year six to seven, which will build up to full production at 16-20 years,” he said.
“Then once you have got them you have got them for decades.”
The industry group, established in 2011 to assist growers to grow walnuts, has 80 members, most of whom have orchards in Canterbury, with a few in Hawke’s Bay, Wanganui and Wairarapa.
The group produces 350 tonnes of walnuts annually off 574ha across orchards ranging in size from 50-4000 trees.
A dry climate and good draining soils are preferable for walnut production, the reason Canterbury is home to a large fraction of NZ’s walnut orchards.
Commercial walnut growing started in NZ in the 1970s and by 1987 the NZ Tree Crops Association was on the hunt to find suitable cultivars to work in NZ conditions.
Trials unearthed some exciting new high yielding, reduced disease varieties with walnut tree specialist nurseries now based at Banks Peninsula in Canterbury, Nelson and Palmerston North.
“We are a new industry – an exciting emerging industry,” Horsburgh said.
“Growers and researchers have worked out the fundamentals such as set-up costs for establishment and orchard development, profitability, recommended cultivars, orchard management and suitable machinery for harvesting and processing.
“We have all the pieces of the puzzle in place, but there are still many areas for ongoing progress and improvement to reach full industry potential.”