Have some questions about the soil sampling process for Carbon by Indigo? Click on any of the following question links to get your answers.
What type of samples do you take?
We take three types of samples that are analyzed across four methods:
Test | Purpose | Method |
Soil Carbon | The measure of organic carbon concentration to a depth of 30 cm. | Dry combustion |
Bulk density | Mass of soil per given volume to 30.5 cm and measure of compaction required for carbon stock calculations. | Volumetric core |
Composite: pH and soil texture | The measure of soil acidity and relative clay fraction. Both inform the model of environment-specific conditions. | 1:1 soil to water and hydrometer |
Note that the soil sampling we conduct will only measure particular soil attributes – it is not comparable to a traditional soil analysis for fertility or a Haney Test.
As a result of this sampling, what can I expect to learn about my sampled fields?
If you would like a copy of your soil sampling report one can be provided to you upon request. The report that will provide a snapshot of your fields' soil properties (e.g., organic carbon concentration, bulk density, pH, texture) at the various sampling points. The report will also help you understand the inherent potential of the field to build soil carbon and how its average result compares to the other measurements collected in Indigo's program. It is important to note that initial soil measurements do not directly translate into credits/crediting potential.
Who is coming to sample my fields and what will they know about my fields?
Indigo uses a third-party vendor to conduct the soil sampling on your fields. When they arrive, the only information they'll have about you is your address and which fields have been selected for sampling. They are not Indigo employees and are not familiar with Carbon by Indigo program specifics. If you do have any questions about sampling or the Carbon program more broadly, please reach out to Indigo using the chat box in your Carbon by Indigo account.
Which fields will you sample and when will I know when the sampler is coming?
An Indigo rep will reach out to share which fields have been selected for sampling. In addition, they will work with you to determine the best weeks to visit your operation(s) for sampling. The sampler themselves will reach back out 24-48 hours prior to their arrival to confirm the specific time and date.
Why have some of my fields been chosen and not all?
Not all fields will be selected for sampling. Only a subset of fields will be selected and soil-sampled. Indigo uses a statistical approach to represent the changes in soil organic carbon across a large population of fields by sampling a random subset.
How often will you sample my fields?
For the fields that have been selected for sampling, our verifier partners require us to re-sample fields every 3-5 years in an effort to improve the accuracy and understanding of soil carbon across time.
How will my soil sample results be used?
The soil samples will be used to "initialize" soil biogeochemical models. Starting soil organic carbon stock is a critical input to understanding the impact of practice changes on changes in soil organic carbon over time. Instead of taking samples from every field in the program, we use soil samples from a subset of fields, together with farm records entered on all fields, to estimate how practice changes affect soil carbon and emissions under different conditions for fields with similar characteristics to yours.
When can I expect to see my results?
When: There are a few key steps that take place between your soil sample(s) being taken and you can request your report 6-8 months* later.