National Soils Archive (NSA)

The National Soils Archive (NSA) underpins the data within the National Soils Database (NSD) as well as the data from Topoclimate South and MfE-funded Land Use and Carbon Analysis System (LUCAS) Programme.

As some of the samples date back to the 1930s the collection is a valuable resource for investigating soil chemical properties before topdressing of NZ farms became common, and before international testing of nuclear bombs. In addition, the collection has been a valuable asset for investigations into the reflectance of various electromagnetic wavelengths from soils.

A corridor in Manaaki Whenua's National Soil Archive (NSA) facility.

The NSA is a collection of some 35,000 dried and sieved soil samples. The earliest soil sample (Ref. SB510A) was collected by Harry Gibbs in 1939 - an A horizon (0-5 inches) of a Mataurau silt loam from Hawkes Bay. Most samples were collected through soil survey work processed by the soil chemistry laboratory of the DSIR Soil Bureau until 1992, and relate to published DSIR soil survey publications. Associated chemical, mineralogical and physical data on the samples is recorded in the National Soils Database.

The collection is not a complete set of samples - not all soils in the database are present and not all horizons for individual profiles remain in the collection. Despite this incompleteness, the collection is an impressive archive of soil samples from throughout New Zealand.

After 1992 soil samples were added to the collection after analysis by Manaaki Whenua's Environmental Chemistry Laboratory. These later samples originated from commercial contract work carried out by Landcare Research such as the Southland soil survey (Topoclimate South) and the MfE-funded Land Use and Carbon Analysis System (LUCAS) Programme.

An archived soil sample from the Central Otago soil survey (1959).