Carbon Credits (Carbon Farming Initiative—Measurement of Soil Carbon Sequestration in Agricultural Systems) Methodology Determination 2018
15Sampling variance of the soil organic carbon stock for a stratum
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15 Sampling variance of the soil organic carbon stock for a stratum
Calculate the sampling variance of the average soil organic carbon for each stratum h (the View image in the official source, in tonnes of carbon per stratum squared, using the following equation:
SOCi is the SOCi for each sample i from stratum h, in tonnes of carbon per hectare, given by equation 9 or 10.
View image in the official source is the average soil organic carbon stock in each stratum h, in tonnes of soil organic carbon per hectare, given by equation 15.
16 Average total soil organic carbon stock for a CEA
Calculate the average soil organic carbon stock for each CEA (the View image in the official source), in tonnes of carbon per hectare, using the following equation:
View image in the official source is the average soil organic carbon stock in each stratum h, in tonnes of soil organic carbon per hectare, given by equation 15.
H is the number of strata for the CEA.
17 Sampling variance of the average soil organic carbon stock for a CEA
Calculate the sampling variance of the average soil organic carbon for each CEA (the View image in the official source, in tonnes of carbon per CEA squared, using the following equation:
View image in the official source is the sampling variance of the average soil organic carbon for each stratum h, in tonnes of carbon per CEA squared, given by equation 16.
18 Soil organic carbon stock for a CEA
(1) If carbon analysis is undertaken on a homogenised sample as outlined in the Supplement—the SOCCEA, in tonnes of soil organic carbon per CEA, is given by the following equation:
View image in the official source is the average soil organic carbon stock for a CEA, in tonnes of carbon per hectare, given by equation 17.
(2) If carbon analysis is undertaken on an intact core as outlined in the Supplement— SOCCEA, in tonnes of soil organic carbon per CEA, is given by the following equation:
View image in the official source is the average soil organic carbon stock for a CEA, in tonnes of carbon per hectare, given by equation 17.
ESM is the equivalent soil mass, in tonnes per hectare, for the CEA determined in accordance with section 6 of this Schedule.
gGCEA is the mass of gravel across the CEA based on the average gravel mass of all samples from the CEA, in tonnes of gravel per CEA, determined in accordance with any requirements of the Supplement.
19 Sampling variance of the soil organic carbon stock for a CEA
(1) If carbon analysis is undertaken on a homogenised sample as outlined in the Supplement—the View image in the official source, in tonnes of carbon per CEA squared, is given by the following equation:
View image in the official source is the sampling variance of the soil organic carbon in each CEA, in tonnes of carbon per CEA squared, given by equation 18.
(2) If carbon analysis is undertaken on an intact core as outlined in the Supplement—the View image in the official source, in tonnes of carbon per CEA squared, is given by the following equation:
View image in the official source is the sampling variance of the soil organic carbon in each CEA, in tonnes of carbon per CEA squared, given by equation 18.
View image in the official source the total mass of gravel for a CEA calculated using the mass of gravel in a single sample i, in tonnes, and determined in accordance with any requirements in Supplement.
gGCEA is the mass of gravel across the CEA based on the average gravel mass of all samples from the CEA, in tonnes of gravel per CEA, determined in accordance with any requirements of the Supplement.
n is the number of samples analysed for gravel in the CEA.
Division 4—Calculating the creditable change in soil organic carbon stock
20 Calculating the creditable change in soil organic carbon stock in a project area for a reporting period
(1) The creditable change in soil organic carbon in a project area associated with a 60% probability of exceedance for a reporting period (the View image in the official source), in tonnes of CO2-e, must be calculated in accordance with Subdivision 2 or 3.
(2) The relevant Subdivision must first be applied to the 0–30 cm layer.
(a) the 30–x cm layer must be analysed separately; and
(b) the results of the analysis of the 0–30 cm layer and the 30–x cm layer must be added together or combined to apply the relevant Subdivision to the 0–x cm layer in accordance with any requirements in the Supplement.
Note: The addition or combining of the results in accordance with the Supplement may include requirements for weighting or adjustments to ensure that they are applicable to the equations and overall carbon stock of the sample.
Subdivision 2—Where only baseline and 1 subsequent sampling round conducted
21 Application of this Subdivision
This subdivision applies to the calculation of View image in the official source if only the baseline sampling round and 1 subsequent sampling round have been conducted in relation to the project area.
Note: For when 2 or more subsequent sampling rounds have been conducted—see Subdivision 3.
22 Change in carbon stock between sampling rounds
Calculate the change in soil organic carbon stock between the baseline sampling round t0 to the first subsequent sampling round t1 (the View image in the official source, in tonnes of soil organic carbon per CEA, using the following equation:
Calculate the standard error of the mean difference between total soil organic carbon for each CEA between the baseline sampling round t0 and subsequent sampling round t1 (the View image in the official source), in tonnes of soil organic carbon per CEA, using the following equation:
View image in the official sourceis deemed to be 60, based on a conservative estimate of the probability that the true soil organic carbon stock value will exceed the calculated value.
25 Degrees of freedom for students t test
(1) If Subdivision 2 of Division 3 applied—calculate the degrees of freedom df to use the one-tail student’s t test in equation 27, using the following equation:
(2) If Subdivision 3 of Division 3 applied—calculate the degrees of freedom df to use the one-tail student’s t test in equation 27, using the following equation:
26 Change in carbon stock in a CEA with 60% probability of exceedance
Calculate the change in soil organic carbon stock for the CEA between the baseline sampling round and subsequent sampling round associated with a 60% probability of exceedance (the View image in the official source), in tonnes of carbon per CEA, using the following equation:
27 Change in carbon stock in a project area with 60% probability of exceedance
Calculate the change in soil organic carbon stock for a project area between the baseline sampling round and subsequent sampling round associated with a 60% probability of exceedance (the View image in the official source), in tonnes of carbon per project area, using the following equation: