What's the issue - in short?
We have identified a conversion/mapping issue with the carbon tab management practices with the update from the CFT1.0 SOC (Soil Organic Carbon) model format to that of CFT2.0.
For a limited number of assessments, this issue may cause discrepancies in the practice changes described in your CFT2.0 assessment, potentially leading to inaccurate emission results.
Am I affected?
The issue might affect any of your crop assessments in the webapp (not API), that were in place at the time of the CFT2.0 release on 26th April.
Any beef and dairy assessments that are using one of the affected crop assessments will also represent this error.
What do I need to do?
You don't need to to anything. Our team has been hard at work developing a fix which is currently in test and we have automatically corrected your affected assessments.
If you have made any updates to the carbon tab of your older crop assessments (created in CFT1.0) since the CFT2.0 release on 26th April, those updates will be overridden by the fix script. To keep hold of that information we would recommend making a note of those updates (via aggregation report or assessment export if you're a CFA member, or via screenshot if you're a non-member user).
Communications surrounding this issue have been sent out to all CFA members. Those who have been affected have been directly contacted and received their list of affected assessments. We also held a 2 member webinars about this issue on the 10th and 30th August.
What's the issue - in more detail?
As part of the method updates to IPCC 2019 that were introduced in the CFT 2.0 release, carbon practice changes recorded on crop assessments in CFT1.0 had to be converted, in data terms, to align with the 2.0 SOC model.
We have established three issues with the translation of crop assessments from CFT v1.0 that are run through CFT v2.0:
1 - No Fertiliser added in
CFT 1.0 assessment
Where a crop assessment in CFT1.0
had no fertiliser inputs, the issue caused no carbon practice changes (from the
Carbon tab) – land use, tillage, cover crops, to be written to the
assessment when it was updated in CFT2.0. This results in the full
impact/benefit of these carbon changes to be missing in the CFT2.0 version of
the assessment.
2 – Carbon Tab Checkbox Issue
In CFT1.0 a carbon practice change
(land use, tillage or cover crops) is active in the calculation if the
corresponding checkbox is checked.
If a practice is entered and the
checkbox is subsequently unchecked, the practice is not considered in the
calculation. The practice is recorded in the database but not used.
When the assessment is
recalculated in v2.0, where a practice had
been entered and the checkbox was unchecked, the issue caused the practice to
be included in the assessment calculation in v2.0 when it should not have been.
3 – Carbon Flow Rule Issue
Where an organic fertiliser has
been recorded in the Inputs tab in the assessment in CFT1.0, this is included in
the SOC model in CFT.0 and captured as a carbon input within the Carbon tab in
CFT2.0 for example as Medium C, High C with Manure etc. This is in line
with including it for the IPCC 2019 SOC modelling.
Various organic fertilisers may
exist on an assessment and have been started as a practice any number of years
ago (up to 20). Carbon input may, through successive practices, increase over
time but where they all are continuing to the year of the assessment, in no
case should the carbon intensity reduce.
Where there is a high carbon
practice that is followed by a lower carbon practice, the CFT2.0 recalculation of
the CFT1.0 assessment creates an error assumption within the calculation of
ill-formed practice changes representing ‘no-change’ for land use, tillage and
cover crops. So again does not reflect the impact of carbon changes
correctly.
In all three cases the assessment may be under representing
emissions where the practices created additional emissions that are not being
included in the assessment, or conversely under representing sequestration
where the removals are not being included in the assessment.
Extensive efforts have been undertaken to address a very complex issue and our team is rigorously developing and testing every scenario for a comprehensive resolution, and we have now resolved this issue.