The area of Auckland land being farmed is 25 per cent less than just over a decade ago, likely because more is being used for housing.
Around 14.1 million hectares (ha) were farmed in this country in 2014, down from 15.6 million ha in 2002, according to Ministry of Business Innovation and Employment data.
Across New Zealand, that's a reduction of 9.3 per cent.
Auckland was leagues ahead of this nationwide average.
Its 223,000 ha of farmland in 2014 was more than 25 per cent less than the 302,000 ha in 2002.
Canterbury, New Zealand's largest farming region by geographic size, was also ahead of the curve with a 14 per cent decline over the 12-year period.
In 2002, 3.2 million ha were farmed in the region, compared to 2.7 million ha in 2014.
ASB rural economist Nathan Penny believed the biggest contributor to the nationwide decline would be urbanisation.
"Particularly in somewhere like Auckland - think about a lot of the residential developments in South Auckland and north and west, a lot of them have come out of farmland," Penny said.
In Canterbury, particularly post-earthquake, land was needed outside the city for housing in places such as Rolleston and Rangiora.
"You'd imagine that's where quite a bit of development has happened on what was previous rural or life-style block land," Penny said.
While the area of land being farmed in rural strongholds like Waikato and Otago had dropped, the decline over the 12 years was smaller at 6.8 per cent and 3.7 per cent respectively.
In Hawkes Bay, the area of land farmed declined 150,806 ha between 2002 and 2014, down 16 per cent.