Trees would also play a key part in future nutrient management, they were told.
For farmers on irrigated properties the challenge of integrating irrigation systems and trees might appear daunting but there were a number of successful examples of trees and irrigation existing in unison around New Zealand, leading farm foresters said.
The workshop highlighted the growing importance of trees in irrigation development and nutrient management.
Trees would become an increasingly important component on intensively managed farms, retired researcher and New Zealand farm forester Nick Ledgard told the workshop attendees.
“It’s all about sustainability in the long term and the marketplace is becoming increasingly concerned with where we grow product,” he said.
“They are not so interested in the vast pastures with not a tree in sight.”
Trees were an integral part of sustainably managed land, he said.
“They will be increasingly viewed as such by a marketplace wanting good product grown on animal- and environmentally friendly farms.”
The record winds last spring that toppled 800 irrigators and left a multi-million dollar trail of destruction in Canterbury provided the focus for the Mid Canterbury workshop – getting it right with trees on irrigated land.
Shelter belts flattened to make way for irrigation in changing farming practice might make a comeback after last September’s winds.
Critical lessons had been learned and farmers and the industry acknowledged preparedness was needed to ensure a safe, profitable, and sustainable business, Ledgard said.
“We need shelter to protect irrigators and we need management that minimises wind-throw.”
A number of hardy native shrubs and small trees could be planted on the plains that would be suitable for centre pivots, where generally vegetation needed to be less than three metres, he said.
However, it was early days for recommendations on the best species and layouts.
Mayfield farmer Tom Corbett hosted the workshop field trip on his property, where he has developed irrigation to fit shelter planted on the family farm since 1878.
Centre pivots had been GPS-mapped and designed in a curve to retain almost all existing shelter belts on the farm.
Where trees did have to give way to the irrigator, new trees were planted.
“I had no irrigator damage in the winds and I believe it was the shelter belts that saved my irrigators,” Corbett said.
A third pivot is about to be installed and the fast-growing Lealand trees that will protect the irrigation system have a three-year head-start.
Canterbury was a tough place to grow trees and what to grow was a personal judgment but planting the right trees in the right place could significantly boost farm profit and management systems to provide multiple benefits, Corbett said.
“Everyone wants shelter quickly. Pines are quick but beautiful takes time,” he said.
Starting irrigation development from scratch is the preferred option of Irrigation New Zealand chief executive Andrew Curtis.
“Get the irrigation right first, know the objectives you want to achieve and how then to achieve them and develop trees into irrigation and farms systems from a blank canvas,” Curtis said.
“If you are using shelter belts as a method for protecting the irrigator it must be done properly, otherwise park the irrigator in the middle of the paddock and tie it down.”
There were still a lot of facts to be proven about the benefits of shelter belts and irrigation efficiency, he said.
AgFirst consultant Nicola Chisholm said the role of trees in nutrient budgeting and farm planning was becoming increasingly important.
The uptake of nutrients was high in vigorous tree species and strategically placed shelter around irrigation and infrastructure, as well as nutrient management, was the future challenge, she said.
“Trees are a long-term investment and the role of trees will only increase in the future, in respect to nitrogen loss and nutrient management on farm.”
The workshop was part of South Island series funded by the Ministry for Primary Industries Sustainable Farming Fund and led by the NZ Farm Forestry Association.
The content of each regional workshop was tailored to meet local farmer interest and community relevance.
