Innovative aerial imaging technology being trialled at sites across New Zealand by researchers at Wellington’s Massey University promises to optimise fertiliser application, saving farmers millions a year. And that’s just a fraction of its potential, says the University’s Professor of Precision Agriculture, Ian Yule.
The Massey researchers are using a state-of-the-art Aisa Fenix hyper-spectral imaging system developed by Finnish company Specim to map hilly terrain across New Zealand, using the resulting data-rich 3-D maps to determine precisely where to apply fertiliser – down to the half square metre.
The cutting-edge system isn't cheap: the university purchased it recently for NZ$500,000 under the ‘Pioneering to Precision’ program, a NZ$10.3 million Primary Growth Partnership (PGP) between Ravensdown Fertiliser Co-op and New Zealand’s Ministry for Primary Industries (MPI).
The Aisa Fenix technology was chosen after initial trials conducted under NZ conditions achieved outstanding results. Currently, it’s the only tool of its type in the Asia-Pacific region.
How does the Aisa Fenix imaging technology work?
The cutting-edge Aisa Fenix tool “was originally developed to help the military find things like camouflaged tanks and it can also identify different types of soils”, says Massey University’s Professor Ian Yule.
“It’s being used in telescopes to figure out the mineralogy of Mars, so it is pretty amazing technology.”
The tool employs hyper-spectral imaging to detect the ‘unique signatures’ of objects or land areas, based on a near-infra-red reflection scanned by the sensor installed in a plane. It can sense up to 1,000 hectares an hour and has the capacity to:
- differentiate between different types of soils;
- detect the presence of key soil nutrients including nitrogen, potassium and phosphate;
- distinguish between differing types of vegetation and between live and dry matter;
- pinpoint diseased plants and invasive species;
- estimate crop yield and biochemical properties.
“The Fenix effectively completes a whole nutrient analysis for every square metre of a farm, with 12,000 readings per hectare when flown at 2,000 feet above ground level,” explains Professor Yule.
“Each pixel in the image has 448 layers of information, which can be used to represent the nutrient, energy and dry matter concentrations as well as [to] discriminate between varieties and cultivars, [and] estimate yield and biochemical properties.
“This gets over many of the difficulties of measuring spatial variation and, when combined wih a GIS, further enhances our ability to handle vast quantities of data in order to assist in decision-making.”
The ‘data cube’ produced forms a detailed 3-D map of the terrain that can be analysed to ascertain the precise nutrient status and condition of every square metre of land it scans.
“It is really like conducting a herbage test over every square metre of a farm or wider landscape,” the professor says.
And using hyperspectral technology rather than conventional laboratory measurements means you can use one sample to run several tests. “An N assessment can be completed, and other parts of the data cube can be used for P, K, and S, for example,” says Professor Yule.
“The method is faster than chemical analysis; the information is reliable; the spatial variation can be understood; and the whole farm can be sensed rather than attempt[ing] to extrapolate whole-farm results out of a few sample points.
“The sensor effectively gives the user a wide-ranging analysis tool with total coverage of every square metre of the landscape.”
The following video explains how the Aisa Fenix tool works in more detail.
How is the team using the Fenix to improve fertiliser use?
While it is relatively simple for those growing crops on flat land to soil-test paddocks for fertility, hilly sites can take far longer to sample.
Current top-dressing aircraft tend to take a ‘cover-all’ approach, assuming the land’s nutrient status is more or less uniform and blanketing farmland with fertiliser. This typically leads to over-fertilising some areas, leading to wastage and harmful run-off; and under-fertilising others, resulting in poor crop growth and reduced yields.
The Massey University researchers are using the Aisa Fenix tool to map key crop, soil and environmental attributes via aerial remote sensing. The new technology could be a game-changer, especially for those on hill-country farms, says Ravensdown’s technical development manager Michael White.
“[If we] have the sensitivity to give us a map across that hill-country farm,” he says, “that would be a huge step forward.”
The 3-D maps generated by the Fenix are being used in conjunction with advanced computer software linked to the aircraft’s GPS and a high-tech hopper to deliver fertiliser exactly, and only where it’s needed.
“It’s a piece of software where the GPS talks to the computer in the plane and that controls the gate that opens and lets the fertiliser out,” explains White. “If we have sensitive areas… we don’t want to put fertiliser on, then we program the software in the aircraft not to put it on there.”
“Previously, most of the control was in the hands of the pilot. But here, we’re trying to give the pilot more ability to fly more safely, so the hopper opens automatically – and that’s new.”
The cutting-edge software is also able to adjust instructions to compensate for variations in wind speed and direction, and for differences in terrain.
How precise is the new system?
In recent field trials over Pickwick Farm near NZ’s Whanganui to test fertiliser spread, Massey University’s Dr Miles Grafton, senior lecturer in precision agriculture, and PhD student Sue Chok placed half-metre-diameter cones at key points across several paddocks to catch fertiliser as it drifted groundwards, enabling them to ascertain how accurate this sophisticated ‘precision agriculture’ tool is in practice.
“We collect the fertiliser in a bag,” explains Dr Grafton. “Each bag is labelled so we know which cone it has come from… if the rate is 100kg/hectare, then we’d expect to get about two grams.”
Trials so far show that fertiliser is being dropped accurately, with each cone catching the expected two grams of it per pass.
The team is still working on refining and calibrating the on-board technology, notes Chok. “We have three sets of areas and three sets of cones; what I am trying to see is the relationship between application rate, the speed the plane is travelling and the width at which it spreads,” she says.
The seven-year Pioneering to Precision program, launched in June 2013, is due for completion in October 2020.
If successful, it is expected to “transform the way fertiliser is applied in farming in New Zealand … improve the profitability of hill country farming, and generate earnings of NZ$120 million per annum by 2030 from additional exports of meat and wool” and net economic benefits of NZ$734 million between 2020 and 2050.
A Fenix-led future for NZ?
A condition of the Premium Growth Partnership’s part-funding of Massey University’s Aisa Fenix purchase is that the University makes the high-tech tool available to third parties, with priority given to Ravensdown, MPI and other associated parties until the program’s completion in 2020.
Massey commercialisation manager Dr Russell Wilson says the university has partnered with Aerial Surveys, which has had two of its aircraft kitted out to accommodate the imaging system and had pilots and technicians trained in the use of the new tool. The planes can be deployed anywhere in New Zealand.
“Aerial Surveys would fly the area, capturing the data and then it would come to Massey for specific analysis based on the key questions the client wants answered, with results presented in a 3-D virtual map,” Dr Wilson explains.
Ravensdown hasn’t yet converted any of its aircraft but technical manager Michael White says Ravensdown would not have entered into a Primary Growth Partnership unless it thought the remote fertiliser mapping project had a good chance of succeeding.
“We’re in the third year of the project now, and we have enough confidence in it,” White says. “It’s hit the markers so far. It’s early days for getting it into our … Ravensdown [aircraft], but we haven’t shut the door, and others might choose to use it.”
Massey University is currently amassing a spectral-image library of species to help regional councils and industry sectors, including horticulture and forestry, that may be interested in using the Fenix aerial mapping service.
Sky’s the limit: potential applications for the Fenix in farming, forestry and environmental management
The potential of the Aisa Fenix goes far beyond optimising fertiliser use, believes Professor Yule.
He says the new remote-sensor technology will allow the collection of “unprecedented levels of data” about the nutrient content of large tracts of land, including previously inaccessible terrain.
“This is a game-changer,” the professor asserts. “It’s like turning the whole of New Zealand into a living lab, where you can observe exactly what is going on and describe it in greater detail than ever before.”
Professor Yule believes the new tool has the power to transform farming across New Zealand (and, potentially, the world), boosting the efficiency, profitability and green credentials of the sector.
“It would be a great advantage for accurately applying fertiliser on hill country, but also great for the dairy sector,” he says. “You could put the sensor over a whole catchment to show you where your hot spots are – to help determine where there is nitrogen run-off.
“We can’t soil-sample every part of a farm but we know it’s hugely variable. With this tool, we can overcome the sampling limitations by mapping whole landscapes, and provide data about what type and quantity of fertiliser is needed,” Professor Yule contends.
“[We can] assess pasture quality over the whole farm to help farmers determine stock-carrying capacity and to locate the good-quality pasture where they can fatten younger stock.
The tool could also be used to detect invasive weeds and diseases over large areas, even in dense bushland and difficult terrain - quickly, accurately, comprehensively and for a comparatively low cost.
“You could fly over bush and identify if there is any invasive species, something that is really expensive to do with a helicopter or with people on the ground,” says Professor Yule. “So this is a really cost-effective way to tell if there are weeds or diseases present."
“You could determine the exact number of kauri trees in a forest, for example, and any diseased trees would stick out.
"There is also huge potential for orchard-based industries, like kiwifruit growers, who could identify things like the PSA vine-killing disease way before the human eye could detect it,” he notes.
“And there are opportunities for huge environmental benefits, too.”
“This is an extremely versatile and powerful technology.”