Soil Survey links
The soil survey can tell you a lot about the soil on your garden-farm. In the US, most of the soils have been surveyed and there is detailed info about pH, sand fraction, clay fraction, CEC, carbonate content, organic matter content and more. These are a snapshot of what the soil was like when it was surveyed (maybe 40 years ago), not what it is like today. But it is a good starting point. Definitely worth looking into for your soil, especially in the US where you may simply click on a map to get the report.
- United States
- This is the main one! SoilWeb (UC Davis): http://casoilresource.lawr.ucdavis.edu/soilweb/
- Soil usage classifications are defined here: Soil Classification Definitions
- If you are really into it, here are the geochemical and mineralogical maps for the US: https://pubs.usgs.gov/sir/2017/5118/index.html
- And this is the link to the USDA database: http://websoilsurvey.nrcs.usda.gov:/app/HomePage.htm
- Canada
- Here is the overview: https://sis.agr.gc.ca/cansis/index.html
- These are probably the best links, scroll down for provinces: https://sis.agr.gc.ca/cansis/nsdb/dss/v3/index.html
- Australia
- Soil Resource Information System: https://www.asris.csiro.au
- United Kingdom
- Soil Observatory: http://www.ukso.org
- Europe
- Topsoil physical properties: https://esdac.jrc.ec.europa.eu/content/topsoil-physical-properties-europe-based-lucas-topsoil-data
- New Zealand
- The digital soil map: https://smap.landcareresearch.co.nz
Soil Carbon
- World wide map of soil carbon in the past, present and projected future: https://soilsrevealed.org