The car-stopping splash of yellow was a favourite haunt of selfie-takers two years ago.
But there’s more to Poplar Grove Farm at Kingsdown, just south of Timaru, than meets the eye.
Mr Darling has put his hand up to be the South Island’s first Growers Leading Change (GLC) Pathfinder demonstration farm, for growers ready to take on new ideas and technologies.
He wants to reduce his reliance on agrichemicals and fertiliser by using beneficial insects and soil nutrients on the farm and is tapping into a new Foundation for Arable Research (FAR) initiative to help him do this.
The GLC programme encourages arable farmers to develop, test and introduce new ideas, technologies, and ways of working to improve their farm, industry and community sustainability.
How the Pathfinder farm plans to transition, particularly in nitrogen management over the next 12-18 months, will be revealed at a field day at the Darling property on September 27.
Mr Darling said they had progressively been introducing measures to wean some of their reliance on chemicals, which were cost-saving with flow-on environmental benefits.
"We want to understand more about what we are doing. We also want to know how far we can go in reducing nitrogen applications without impacting on yield, as yield is always key."
The fourth-generation grower and his wife Amy lease Poplar Grove Farm, including a 250ha home block and a 250ha leased neighbouring property, from his parents Warren and Joy Darling.
Much of the rolling downs farm is in feed wheat and barley. The eye-catching sunflowers are supplied to Rolleston-based Pure Oil, along with oilseed rape, for processing into high-value cooking oil. Turf ryegrass for seed and fava beans are also grown.
There’s no livestock, as the heavy clay soils aren’t suitable for dairy grazing.
Another crop on the farm made headlines in 2015 when Warren Darling set a world record yield for barley of 13.8 tonnes per hectare (t/ha). The record was overtaken last year by United Kingdom grower, Tim Lamyman, with a 14.2t/ha yield.
Mr Darling said the family had been unable to replicate the record yield since, as the world-beating effort coincided with a perfect year for growing feed barley.
They were still spending the same amount to set crops up for high yields, but weren’t getting the return on investment because of poor weather. Yields were being governed by wet and dry spells, hailstorms and a lack of sunshine at peak flowering, he said.
This was leading him to question their high-cost and high-input cropping programme in favour of a less-prescriptive approach, which responds better to the season by using soil nutrients and beneficial insects.
"With a high-input programme, we are relying on a lot of chemicals that you can see are slowly getting banned around the world."
The Darlings have moved to adopt this approach, with information from one hectare grid soil sampling the past seven years being used to apply nutrients at variable rates across paddocks.
Dual sensor cameras installed last season on the roof of their tractor automatically vary nitrogen application rates depending on a crop’s density and greenness. The cameras are calibrated to the type of crop and growth stage.
Along with soil nitrogen testing, this reduced nitrogen applications by 15% last year, compared with a blanket rate.
Furthermore, there’s been no impact on yields — while nitrogen, their biggest spend, has at least doubled in price the past two years.
They haven’t ploughed or burnt any crop residue for 15 years, instead working to build organic matter and improve their soil biology.
FAR senior cereals researcher Jo Drummond is the key researcher for the Darlings’ Pathfinder farm.
She said nitrogen fertiliser was the biggest on-farm cost, so it was important for growers to make sure it was being used in the most efficient way possible.
"It’s great to see Andrew and Amy using tools and technologies to really understand soil supply and crop uptake, which can provide opportunities to cut back on fertiliser use without compromising on yield and profitability.
"Likewise, understanding the population dynamics of beneficial predator and parasitoid species can reduce the need for foliar insecticides, not just on your own farm, but across a region."
