Drones head for hill country

Drystock farmers could one day be using drones to help deliver precision fertiliser applications on hill country, Gerald Piddock reports.

Drones are coming to a farm near you.

They are already here, Ravensdown chief science officer Ants Roberts told farmers at Limestone Downs’ recent annual field day. ‘‘Even if you don’t know it yet.’’

These small unmanned aerial systems, or drones, could be used by farmers to make precision fertiliser applications on sheep and beef hill country.

The sheep, beef and dairy farm south of Port Waikato was used for the study because it had extensive historical data available for researchers.

The technology is part of $2.2 milllion Primary Growth Partnership project to better assess soil fertility on drystock properties.

It explores whether aerial imaging using a drone can accurattely measure soil fertility. The data is then compared with 400 soil samples taken four times a year from the property.

The data is being collated and assessed by Massey University, and AgResearch and Ravensdown are spending $2 million developing the hardware around the technology. Roberts called the technology a ‘‘revolution’’ for hill country farming. He hoped the project would change hill country thinking and improve productivity.

It gave farmers the confidence of knowing their fertiliser was put where it was supposed to be, he said.

‘‘You can be in Hawaii and you know that your fertiliser will be spread in the right place at the right time.’’

But there were a few teething issues. The biggest being that the technology

Primary Industries Minister Nathan Guy holds a drone shortly before it was launched during a demonstration at Limestone Downs in northwest Waikato. From left are Heijo May of drone specialists Geosystems, Guy, Ravensdown’s Mike Manning and C Alma Baker Trust deputy chairman David Frith. was running ahead of the argonomy.

‘‘We can take lots of pictures of farms, lots of different colours and sensors, but it’s turning that into some information useful to you to make management decisions on the farm.’’ He called this the $64,000 question. The technology was also expensive. It was a $70,000 investment for a complete system.

Roberts said most New Zealand hill country had traditionally received blanket application of fertiliser where the same rate was spread over the whole farm regardless of its topography.

Using a map of Limestone Downs and advice from farm staff, Roberts and his team set up a simple variable rate plan for the farm. This plan saw exclusion zones mapped out the farm where no fertiliser was spread. When Limestone Downs was mapped out, 19 per cent of the dry stock operation fell into that category.

Once the data was drawn on the map it was then converted into ‘‘shape files’’ by Ravensdown’s team in Christchurch. These files told the computer that controls the plane’s aperture doors which determined how much fertiliser each paddock was to receive.

This allowed the right rate of fertiliser to come out at the right time and avoid applications to areas of bush, rocky outcrops, wetlands and riparian strips. ‘‘The pilot just has to fly the plane, which is good for them. The computer and the aperture doors should do the rest,’’ Roberts said.

A full variable rate meant applying different amounts of nutrients to different areas of the farm to maximise its productivity.

‘‘There is a value proposition to going from blanket to simple variable rate applications and a slightly bigger one going to full variable rate applications.’’

Among the 100 farmers watching a fixed-wing drone in operation was Primary Industries Minister Nathan Guy. He said the project was important if the goal of doubling the country’s primary exports from $32 billion to $64 billion by 2025 was achieved while remaining environmentally sustainable. ‘‘It’s hugely important when you think about lifting the performance and profitability inside the farm gate, but also allowing you to manage your environmental footprint better than you are currently doing already.’’ The project was hugely exciting considering the challenges farmers were facing from an environmental standpoint, he said.