An arable farmer wanting to switch up his methods to become more sustainable is one of the first to participate in a new research project led by the Foundation for Arable Research.
South Canterbury fourth-generation farmer Andrew Darling, who grows wheat, barley, sunflowers and oil seed rape, will trial how he can phase out use of nitrogen over the next 18 months.
He said an ever-increasing fertiliser bill incentivised him to work with FAR to scale back on crop inputs.
"Last year around spring, when crop growth is key and we're starting to put on urea products and nitrogen, the bill was about $700," he said.
"At the moment, it's about $1,350 a tonne of urea. Because we're growing a lot of commodity crops, luckily we are seeing a increase for our end produce as well, but that's fickle as well, and there's still a long way to go until we get the crops off again.
"So, it's managing the inputs as best we can and trying to get as much profitability as we can, basically."
Darling is to work with FAR on its Growers Leading Change initiative, which aims to provides a farmer-led framework for arable farmers to develop, test and introduce new ideas, technologies and ways of working, in order to improve their farm, industry and community sustainability.
His farm in Kingsdown, just south of Timaru, would be the first demonstration farm for the initiative, working to change how nitrogen is used on-farm without compromising profitability.
"We want to understand more about what we are doing," Darling said.
"We also want to know how far we can go in reducing nitrogen applications without impacting on yield, as yield is always key."
Andrew and his wife Amy lease Poplar Grove Farm, made up of a 250-hectare home block and a 250ha leased neighbouring property, from his parents Warren and Joy Darling.
The farm made headlines in 2015 when Warren Darling set a world record yield for barley of 13.8 tonnes/ha, which held the top spot until last year, when it was beaten by
a grower in the United Kingdom with a yield of 14.2t/ha.
Darling said the family had been unable to replicate the record yield since, which led him to question their high-cost, high-input cropping programme in favour of an approach which was less prescriptive, more responsive to the season and better utilised the soil nutrients and beneficial insects already available on the farm.
He said they had already made steps in that space, using 1ha grid soil sampling for the last seven years, and using that information to apply nutrients at variable rates across paddocks.
Dual sensor cameras installed last season on the roof of their tractor automatically varied nitrogen application rates depending on a crop's density and greenness.
The cameras were calibrated to the type of crop and growth stage. This, along with soil nitrogen testing reduced nitrogen applications by 15 percent last year, compared to the blanket rate, with no impact on yields.
They have not ploughed or burnt any crop residue for 15 years, instead working to build soil organic matter and maximise the biology in the soil.
Darling said working with FAR researchers would help them to make smarter changes without impacting crop yield.
"We're doing it anyway, but there will be a bit more science behind it," he said.
"We're trying to maximize every year to get a better understanding of what we are doing with different soil tests, and utilising some tools we have now that changes the nitrogen application to the crop requirements.
"We're getting some very good data sets as well to that. After harvest, we can have a look at how that crop performed and the nitrogen applications that were put on as well and try and make sure we're getting maximum efficiency out of our inputs."
Darling said he was also keen to learn more about the beneficial insects available on his farm to reduce reliance on foliar insecticides through the project.