IPCC direct manure N2O emission factors (EF3), by edition.

EF3 (kg N2O-N per kg N) for the six manure-management labels WHEP's manure engine carries, in two editions. The ef3_source option of the manure engine (see manure_engine_options) and of apply_management_losses() selects one; "ipcc_2019" is the default.

"ipcc_2019": the 2019 Refinement, Vol 4, Ch 10, Table 10.21 (Updated): daily spread 0, solid storage 0.010, uncovered anaerobic lagoon 0, poultry manure with litter 0.001. Liquid/slurry is published as 0.005 with a natural crust, 0 without and 0.005 covered; the first two are carried as "Liquid/Slurry - With Crust" and "Liquid/Slurry - No Crust", and the engine's single "Liquid/Slurry" label takes their mix at the crust share the slurry_crust option selects: "half" (default, 0.0025), "none" (0) or "all" (0.005). Half is GLEAM 2.0's assumption: Supplement S1 footnotes the "Liquid slurry*" of its pig and chicken tables (Tab. 4.8-4.11) "50% of this manure management system is assumed to present natural crust". Its cattle and buffalo tables (Tab. 4.2-4.6) state no share, so the half is extended to them by assumption. Pasture/range/paddock is deferred to Ch 11, whose Table 11.1 (Updated) gives the aggregated EF3PRP 0.004 for "cattle (dairy, non-dairy and buffalo), poultry and pigs" (animal_class == "cattle_poultry_pigs") and 0.003 for "sheep and 'other animals'" ("sheep_other"), the chapter listing goats, horses, mules, donkeys, camels, reindeer and camelids as other animals. Its disaggregated wet/dry pair (0.006 / 0.002) needs a moisture regime per row and is not carried.
"as_shipped": the values the engine read before whep#601, a crosswalk onto ipcc_2019_n2o_ef_direct, which holds 2006 and unpublished values (see its @source). Its "Liquid/Slurry" 0.002 is not the no-crust value (both editions print 0 for that) but the EF3 of pit storage below animal confinements. slurry_crust does not apply to it. Kept so earlier figures stay reproducible.

"Solid Storage" also carries GLEAM's dry-lot shares (see regional_mms_distribution), which Table 10.21 prices at 0.02, not 0.010.

Usage

ipcc_manure_ef3

Format

A tibble with one row per edition, mms_type and animal_class:

edition: "ipcc_2019" or "as_shipped".
mms_type: manure-management system label, plus the two published liquid/slurry crust rows of the 2019 edition.
animal_class: "all", or for 2019 pasture "cattle_poultry_pigs" or "sheep_other".
ef3: kg N2O-N per kg N.
ipcc_system: the published row (or the shipped table's row) the value was read from.

Source

IPCC. 2019. 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Vol 4, Ch 10, Table 10.21 (Updated), pp. 10.91-10.93 (PDF md5 c1784e747af9bb307e93f4170c12679a), and Vol 4, Ch 11, Table 11.1 (Updated), p. 11.13 (PDF md5 06c11d4f5a2b729564f8b3bd1ba11824). Both downloaded from ipcc-nggip.iges.or.jp and checksummed on 2026-10-07.

Measured effect

On FAOSTAT 2020 heads at national grain, Tier 1 direct manure N2O goes from 1.523 Tg (as shipped) to 1.178 Tg, almost all of it the pasture factor (0.010 to 0.004 / 0.003): keeping pasture at 0.010 would give 1.830 Tg. The liquid/slurry crust share moves it between 1.120 Tg ("none") and 1.236 Tg ("all"). In apply_management_losses(), which carries no management N2O on the grazing stream, the 2019 edition moves the nitrogen applied to land by -1.4 to +0.6 percent per species under the Global split.

Examples

ipcc_manure_ef3
#> # A tibble: 14 × 5
#>    edition    mms_type                   animal_class          ef3 ipcc_system  
#>    <chr>      <chr>                      <chr>               <dbl> <chr>        
#>  1 ipcc_2019  Pasture/Range/Paddock      cattle_poultry_pigs 0.004 EF3PRP,CPP (…
#>  2 ipcc_2019  Pasture/Range/Paddock      sheep_other         0.003 EF3PRP,SO (C…
#>  3 ipcc_2019  Daily Spread               all                 0     Daily spread 
#>  4 ipcc_2019  Solid Storage              all                 0.01  Solid storage
#>  5 ipcc_2019  Liquid/Slurry - With Crust all                 0.005 Liquid/Slurr…
#>  6 ipcc_2019  Liquid/Slurry - No Crust   all                 0     Liquid/Slurr…
#>  7 ipcc_2019  Anaerobic Lagoon           all                 0     Uncovered an…
#>  8 ipcc_2019  Poultry Manure             all                 0.001 Poultry manu…
#>  9 as_shipped Pasture/Range/Paddock      all                 0.01  Pasture/Rang…
#> 10 as_shipped Daily Spread               all                 0.01  Daily Spread 
#> 11 as_shipped Solid Storage              all                 0.005 Solid Storage
#> 12 as_shipped Liquid/Slurry              all                 0.002 Liquid/Slurry
#> 13 as_shipped Anaerobic Lagoon           all                 0.001 Uncovered An…
#> 14 as_shipped Poultry Manure             all                 0.001 Poultry Manu…