Water for irrigation has ensured viability, security and sustainability for third-generation farmers Jim and Chris Dennison’s family farming operation.
Jim, 90, who still rides a two-wheel motorbike and spends most of his time these days planting native trees, took over the Hilderthorpe property, just south of the Waitaki River, from his father Harry.
Harry, having walked away from the Southland mud and rabbits, bought the farm for nine pounds an acre in 1919.
The farm was initially a smallholding providing a subsistence existence running 20 sheep over 100 hectares with a few chickens that produced eggs for the local general store.
“It was in a desolate state, fertility was zero and the district pitied the new bride in the district,” Jim said.
His father struggled for years, he learnt how to farm dryland and at its best the farm got to 45 bushels of wheat to the acre (3t/ha).
“And that was after fertiliser became available and he got rid of the couch (grass),” Jim said.
North Otago had a reputation for feast or famine when it came to water and that is why irrigation was explored as early as 1860 by early settlers who saw the potential in the region’s agricultural sector.
“I was irrigating to ward off drought, now I am continually learning how to harness water and manage nutrient, genetic and plant protection programmes better.”
Chris Dennison
In 1907 a severe drought hit the area and the need for water became very pressing.
In 1910 the Government announced the Steward Settlement on the Waitaki Plains was to receive an irrigation scheme and called for tenders for its construction.
The scheme on the south bank of the Waitaki would serve 23 farms with productivity estimated to have increased fivefold by the 1930s, up to 25 bushels to the acre, changing the fortunes of the Waitaki region forever.
Water was hailed as the saviour of the agricultural community and development of the Waitaki water for irrigation, recreation and domestic use has continued, albeit now vastly improved by technology advances.
The Dennison family’s Hilderthorpe property was irrigated from the Lower Waitaki Irrigation Company’s (LWIC) scheme that grew from the backbone of an irrigation race across the Waitaki Plains.
The scheme, originally a Ministry of Works border-dyke gravity scheme, was opened by then Prime Minister Rob Muldoon in 1982, on a wet day.
It was now more than 50% spray irrigation and the company had invested heavily in automation and buffer storage to best meet the needs of its shareholders as well as increase water-use efficiency.
Reliable water from LWIC during critical periods in the growth cycle was crucial to allowing Chris to grow world-beating crop yields.
The Hilderthorpe farm had been irrigated since 1972, initially partially, to fully spray irrigated by 1982.
That original plant had now been replaced with second-generation irrigation systems.
Traditionally, the farm was mixed sheep and beef with some cropping but when Chris started in the family business in 1988 he brought with him a specialist interest in cropping and arable.
In 1999 the farm was separated and now the family has 400ha of cropping with 96% of the land irrigated.
Next to the cropping they have a dairy farm milking 750 cows.
The blocks are farmed as two separate businesses, with 50-50 sharemilkers managing the dairy operation.
Chris is in charge on the cropping farm where wheat, barley, canola, ryegrass and fodder beet are grown.
“My passion is in cropping. In the late 1990s a United Kingdom agronomist visited and said we (NZ) could do a lot better,” Chris said.
“You have the best climate in the world so why aren’t you growing the best crops?” the agronomist asked.
Over a few seasons he taught agronomy methods that Chris took on board.
“In hindsight, back then I wasn’t really harnessing irrigation,” Chris said.
“I was carrying on the same practices as before but just adding water.
“I was irrigating to ward off drought. Now I am continually learning how to harness water and manage nutrient, genetic and plant protection programmes better.”
Irrigation enabled Hilderthorpe to lift its game and expand the operation, create some scale and invest in better technology including precision-farming technology.
“Environmentally, we can target our inputs because we know within a few percent what our potential yield will be.
“We don’t waste any fertiliser or leach nutrients.”
Irrigation meant viability, sustainability and security, Chris said.
A small area, 4%, of the farm was dry and yielded just 5t/ha compared with 11t/ha off the irrigated crops.
“Just add water and there is an incredible difference.
“I would be in a huge hole if not for the high yields I can maintain thanks to irrigation,” he said.
LWIC chairman and a director on the Waitaki Irrigators’ Collective, the umbrella body for wider Waitaki irrigation schemes, Chris hailed irrigation as the saviour of the community.
When irrigation happened for the region in the 1970s some families embraced the concept and adapted, others were daunted and saw it as an opportunity to retire.
Those who didn’t adapt had moved on.
“We’ve spent half our farming life building up fertility and organic matter and utilising water so the paddocks that only took two trailer loads of sheaves are now world class,” Chris said.
Hilderthorpe has earned two world records for crop production, the Guinness world record for highest yield in wheat in 2003 and last season a world record for canola yield.
Waitaki Irrigators’ Collective
Irrigation is woven into the fabric of the Waitaki community through a number of shareholding irrigation schemes, including the incorporated society of independent irrigators, under the umbrella of the Waitaki Irrigators’ Collective (WIC)
WIC represents the interests of 600 farmers irrigating 80,000ha across north Otago and south Canterbury. Its members take water from Lake Waitaki, the lower Waitaki River, its tributaries and connected groundwater.
WIC policy manager Elizabeth Soal said irrigation from the lower Waitaki River was among the most reliable in the country, very close to 100%.
SAFETY NET: Waitaki Irrigators’ Collective policy manager Elizabeth Soal says irrigation provides and economic buffer.
It had provided communities an economic buffer in the recent dry periods.
Average grass growth on the Waitaki Plains was 61kg of drymatter (DM) a hectare a day on irrigated land and 26kg DM/ha/day on dryland.
“If reliability of supply for Waitaki irrigators was reduced, onfarm economic losses would equate to $2.1 million a day,” Soal said.
