By Victoria Rutherford

On Lochiel Farmlands near Pukekohe, Chief Executive Kim Robinson has been using the remote sensing technology offered by Ravensdown and Massey University’s Hyperceptions to map their vegetation and find out how close they are to carbon neutrality.

Becoming carbon zero means on-farm emissions are counteracted by the carbon sequestered by trees. Kim saw the opportunity to use this technology to get an accurate estimate of forest cover for a carbon sequestration assessment.

“[Carbon] is potentially going to cost farmers significantly, so we’re trying to mitigate this by measuring what we’ve already done,” says Kim.

The 3,592ha sheep and beef property at Glen Murray is managed by Kim and Evelyn, running 10,500 ewes, 4,000 hoggets, 540 cows and fattening 1,600–1,700 cattle. It’s medium hill country with flats, separated through the middle by a large gorge.

Plantings for erosion control and fencing waterways have long been a focus for soil conservation and animal welfare on Lochiel Farmlands. This includes established poplar plantations and newly planted poles over much of the property, as well as native bush.

“We started 30+ years ago fencing off bush and scrub blocks and planting them out to give us buffers, so we are a long way down the track,” says Kim. “We have mud-bottom streams and crossings; we had to fence them off to keep out stock.

“It was just the lay of the farm really – that’s what started it; we weren’t doing it for environmental purposes at that stage. That has just happened over time.”

The remote sensing has given Kim a more exact idea of how much planting is needed.

“Whether there is an advantage to what we are doing in the short term is debatable... and I’d say maybe there isn’t, but we are a fair way down the track and we wanted to see our status.”

Kim heard about the AirScan remote sensing (hyperspectral scanning) work done for Ravensdown’s Primary Growth Partnership (PGP) Pioneering to Precision programme, undertaken on a nearby focus farm. Using remote sensing technology, a hyperspectral camera is mounted on an aircraft and flown over a property to collect detailed spatial data that is then processed into vegetation and nutrient maps.

The PGP outcome was to measure soil fertility, with the data gathered then used to make cost-effective and efficient decisions about where to place fertiliser to get the best returns. However, spin-off benefits from the programme include the identification of different forms of vegetation (e.g. the percentage of pasture and different tree species) and the detailed mapping of effective areas, which is what Kim wanted to investigate.

“We have flown the farm and according to the workings of Overseer there is approximately 150ha of planting we need to do.”

Depending on the time and conditions when the farm is flown, shadow areas hide what actually lies below. The team at Ravensdown and Hyperceptions is working to improve the capability of the technology so shadowing is less of an issue, as well as improve plant species identification across the farming landscape.

Kim says to become certified as carbon neutral means being audited. “We have our data in Overseer – we know our number and I’ve talked to Toitū [about carbon certification], we now know what is required to get accreditation.”

Another important consideration was keeping the system closed.

“We are not into buying carbon credits to become carbon neutral, we want to do it ourselves, but by the same token, we don’t want it to have a negative impact on the business. This farm is a business, and it needs to be run like that.”

Kim says he was “gobsmacked” when the mapping revealed they were farming less effective area than they thought. “I knocked a 100ha off because we have a gorge, bluffs and native bush ... but it is quite a bit less.”

Mapping the actual effective area can be beneficial because stocking rates can be better matched, depending on the size and productivity of different areas of the farm.

“Lochiel is a very pretty farm but is not the easiest to run due to dry summers, wet winters and the farm’s topography.”

One of the highlights for Kim has been the level of information detailed in the maps, including slope and aspect, as well as pasture, poplar, pine and native bush classification.

“The mapping has given me a lot more information; it makes you more aware. It’s hugely technical stuff and the attention to detail is bloody awesome, so I believe it will be invaluable.”

For more about Hyperceptions see their website.