Dwindling soil resources prompt national response

Rural production property land use and area change 1996-2016, Core Logic (2017) – based on rural valuation categories.

Food could become more expensive if the current pattern of urbanisation in Auckland is allowed to continue. That’s the opinion of Rodney Councillor Greg Sayers, who wants food security prioritised over housing and is urging Council to prevent some of New Zealand’s elite soils being lost to housing.

It is an opinion shared by Horticulture NZ and Federated Farmers, and will be addressed when the Government considers a National Policy Statement for Highly Productive Land in the first half of this year.

The policy proposes a nationwide approach to protecting good agricultural land for future generations and will stand alongside the National Policy Statement for Urban Development, which came into effect last August.

While urbanisation, land fragmentation and reverse sensitivity issues are the focus of the policy statement, phase two will look at soil quality including erosion, compaction and contamination.

Under pressure

Only about 14 per cent of NZ’s land is categorised as highly productive and it is under increasing pressure from expanding urban areas and a growing number of lifestyle blocks.

The policy statement will introduce consistent policy guidelines which local councils will have to follow when making decisions on land use. But in an opinion piece in the Otago Daily Times late last year, Dr Selva Selvarajah, the founder of Enviroknowledge, says this is the policy’s weakness.

“The window-dressing proposal warrants costly regional and district plan changes, which are unlikely to protect the remaining soils,” she wrote. “It wilfully permits relinquishing our versatile soils for inappropriate subdivisions and infrastructure development, promoting the steady carving of our significant natural features, thus stealing from our future generations for short-term gains.

“Elite soils are national assets and deserve full protection, rather than being traded off cheaply and regularly for housing and roading.”

Cr Sayers says Auckland Council should work with the produce industry to ensure that growing land has blanket protection.

“Reverse sensitivities of sudden urban development potentially disrupting established growing operations need regulation to protect businesses through the buyer agreements and covenants,” he says.

The Ministry for Primary Industries is currently helping regional councils to fund the expansion of S-Map (a national database of soil information) coverage to improve their access to information about highly productive land in their regions.

The National Policy Statement for Highly Productive Land states that the value of this land for primary production is often given inadequate consideration, with more weight generally given to other matters and priorities. “This absence of considered decision-making is resulting in uncoordinated urban expansion over, and fragmentation of, highly productive land when less productive land may be available and better suited for urban use.”

The Land Use Capability (LUC) classification system classifies land into eight classes. Land that has a Class 1 rating under the LUC system is the most versatile and has the fewest limitations for its use, while Class 8 is the least versatile with the highest number of limitations on its use.

Auckland has lost nearly a quarter of its prime agricultural land – of an original 115,000ha, more than 27,000ha has been urbanised. A significant portion of the rest has been lost under roads and structures or compromised by an intense subdivision or development pattern.

According to the Rodney Rural Strategy, published in 2010, a total of 15,418ha in Rodney was converted from pastoral farming and 6039ha was converted from dairying between 1995 and 2008.

This was accompanied by an increase in the area of land occupied by lifestyle properties of 37 per cent.

Nationally, around 29 per cent of land previously used for vegetable production was lost to urban development between 1996 and 2012.


There is a pattern of ongoing incremental, cumulative loss of highly productive land, as decision-makers discount the significance of a parcel of land when considering it in the context of the total area of highly productive land in the region/district.

This was highlighted in a recent High Court decision regarding the location of the Rural Urban Boundary in Auckland.

It also contributed to a large amount of highly productive land being included within the Rural Urban Boundary or zoned as Countryside Living through the Auckland Unitary Plan process.

Discussion document on proposed National Policy Statement for highly productive land.