N CHAIN CALCULATIONS
The amount of N2O emissions related to a given amount of fertilizer N is determined by the entire N chain from the original fertilizer use to the final uses and losses.
This tool deals with N amounts and N2O emissions from a different perspective, following the N from a given source instead of calculating total amounts from different sources.
Therefore it enables detailed calculations of N uptake efficiencies and N2O emissions related to specific crops, crop rotations, and uses such as fodder, food, and fuel; in connexion with fodder, the N is followed through the animals to food and to manure and further through the following crop(s).
Each calculation begins with a specific amount of fertilizer N and follows it through a specific first crop to specific uses and losses, and it follows the recycled N, if any, through specific subsequent crops to specific uses and losses, until the entire amount of N has left the agricultural circulation.
The comprehensive N chain calculations spreadsheet consists of five Sheets; you may open/close the following summaries to see their contents, structure, purpose, and bases:
Sheet A: Introductory part
Sheet B: Danish crop values
All yields and N uptake efficiencies are calculated for each of the Danish soil types and as weighed averages for all Danish soil types.
All values are based upon norm figures/statistics.
Sheet C: N chain calculations, Danish average values
Page C1: Basic values:
All values are based upon norm figures/Danish National Inventories/IPCC Guidelines.
Page C2: Calculations:
Sheet D: N chain calculations, with optional basic values
Page D1: Basic values:
All values are based upon user values/norm figures/Danish National Inventories/IPCC Guidelines.
Page D2: Calculations:
Sheet E: Total Danish N amounts
All values are based upon statistics.
Get the current version of the N chain calculations spreadsheet as OpenOffice (ODS) and use it, and/or get the individual Sheets as PDF and read them:
The N chain calculations form an important part of the basis of the Disproof of the ACP biofuel paper, performed with extended Sheets C and D. Get the extended versions here.
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