Water + Soil: Next Generation S-Map
Manaaki Whenua is leading a 5-year research programme to improve our understanding of key soil characteristics such as water and nutrient transport and include these data in S-Map. This information is critical for water quality and soil management
Regional Councils and others have partnered with Manaaki Whenua to progress this work on several fronts outlined below:
- Capturing data from legacy projects
Historically, progress towards characterising soil water attributes in New Zealand has been limited: the National Soil Data Repository (NSDR) contains measured data for just 313 sites from historical Soil Bureau research. Characterisation has been completed at many more sites, but this valuable information has lain ‘forgotten’ with individual scientists or reports. We are now capturing these legacy to rebuild a modern, world-class soil database. In the first year we have added data for a further 156 sites.
- Characterising new sites
A field programme to sample at least 150 new soil profiles in 3 years will also greatly boost the sites in the NSDR and reduce the uncertainty of information that S-map provides to end-users. In the last year, we have sampled over 60 soil profiles in the Canterbury and Southland regions (with co-funding from Environment Southland). We also have a PhD student studying the soil-water characteristics of stony soils.
- Research to compare the effects of land management on soil water properties
Together with Plant & Food Research, we have started a project to compare how sheep, dairy, and cropping land use affect soil water properties. In collaboration with Lincoln University and Environment Southland, a PhD student is studying the effect of mole and tile drainage systems on soil water properties.
We are also researching the effects of irrigation on soil properties with an aligned Sustainable Farming Fund project, funded by the Ministry for Primary Industries, Federated Farmers, and a range of irrigation companies and industry groups.
- Preparing lysimeter data sets for inverse modelling of soil hydraulic properties
The implications of uncertainty in soil water attributes are being tested using the APSIM plant production model (Plant & Food Research) and the National Hydrological Model (NIWA). This research will also help the co-development of the soil water component of these key models, which are widely used in New Zealand research and decision-making.
While S-map maps the spatial variation in soil types, the National Soils Database (NSDR) stores ‘point’ based data, where soil pits have been dug, sampled, and soil laboratory analysis completed. The NSDR contains descriptions of about 1,500 New Zealand soil profiles, together with analytical data on their chemical, physical, and mineralogical characteristics. The National Soils Database (NSDR) is a crucial part of our legacy soil data in New Zealand, and underpins the soil attribute information that S-map provides. The first database was created in the 1980s and contained records back to the 1950s. In the last 3 years Manaaki Whenua has invested significantly to rebuild the NSDR, to meet international database standards, and allow data from new locations to be entered.
The full NSD contains data on the following:
- The site
- Soil chemistry
- Physical analyses
- XRF Analyses
- Soil / void relationships
- Water retention measurements
Not all sites have the full set of data.