Balin Robertson collecting soil samples by auger in Mokoreta, Southland.
S-map Online continues to be widely used, with over 13,000 active users downloading 65,000 soil fact sheets, which is additional to the direct use of S-map data within end-user tools of organisations such as fertiliser companies, banks, councils and the Overseer nutrient budgeting tool.
Through a funding collaboration between the Ministry for Primary Industries, the Ministry for the Environment, and 12 regional councils, in August 2024 Manaaki Whenua completed an extra 507,000 ha of new soil mapping coverage across some of the country’s best food-producing land. A further 363,000 ha of legacy mapping was replaced with a new soil survey.
The partnership is on track to deliver a further 700,000 hectares of new mapping over the next year.
The newly mapped areas in this update to S-map include:
- 201,660 ha in Wellington – Wairarapa east coast.
- 9,656 ha in Marlborough – upper Wairau River valley.
- 27,655 ha in Tasman – Tapawera valley and Moutere River valley.
- 64,625 ha in Otago – Moa
- 45,999 ha in Southland – Chatton (north of Gore) and Curio Bay,
- 158,000 ha in Northland – Kaikohe, Dargaville and Pouto Peninsula.
Updated mapping of lower-quality legacy mapping includes:
- 123,698 ha in Bay of Plenty – the Kaituna and Maketu water management areas.
- 240,000 ha in Tasman – Motueka hill country.
In addition, in April 2024 the soil water attributes of S-map soils were also significantly upgraded for the first time since 2020. The updated modelling is based on just under 6,000 samples (on 796 sites) held in the National Soils Data Repository, compared with only 4,641 samples (on 684 sites) in the 2020 model. This has much improved the ability of S-map to estimate soil water retention and profile-available water (PAW), including for Pumice, Granular and Allophanic soils previously not well represented in the modelling.
PAW to a depth of 60 cm is used by tools such as OverseerFM. Soils with a low PAW can provide less water to plants than those with a high PAW. The latter tend to be deep, silty, stone-free soils, and the former might be sandy, shallow or stony soils.
