Selection of appropriate materials for construction and on-going use (e.g. topdressing) is critical to performance. NZST I is able to analyse construction and topdressing materials through its NZ and Malaysian based laboratories.

The following materials testing procedures are available: 

Rootzone sands, topdressing sands, bunker sands, blinding sands

• Particle size distribution
• Moisture release curve
• Hydraulic conductivity
• Calcium carbonate content
• pH
• Particle shape and colour (bunker sands)
• Organic matter content

Drainage gravels

• Particle size distribution
• Hydraulic conductivity
• Calcium carbonate content
• Bridging coefficient 

Rootzone and topdressing soils

• Soil textural analysis
• Organic matter content
• Hydraulic conductivity
• Aggregate stability
• Dispersion co-efficient
• Stone content pH

Includes testing to the NZSTI standard specification for topsoils suitable for use as topdressing on soil sportsfields. 

Cricket soils

• Motty test
• Linear shrinkage
• Dust/shine potential
• pH
• Organic matter content
• Soil textural analysis 

Pest and disease diagnostic service
The NZSTI laboratory provides routine pest and disease analysis.   If necessary, disease and pest problems are also referred to specialist entomologists and pathologists employed by AgResearch, Grasslands and MAF. 

Nutrient testing
NZSTI maintains a strategic link with Hill Laboratories Ltd, offering a complete soil test interpretation and fertiliser recommendation service from a chemical analysis of root zones, plant tissue and irrigation water. 

Overseas samples
NZSTI can supply an import permit for clients wishing to have overseas samples of soil, sand or gravel samples analysed. This permit is licensed under the 1993 Biosecurities Act and allows direct entry of samples into New Zealand without the need for complicated border control procedures. 

For more information or any questions, please contact Brendan Hannan