Skip to contents

Crop sources for the irrigated:rainfed regime yield ratio

Source: R/datasets.R
regime_yield_crop_mapping.Rd

Gives every primary crop production item the two sources of its irrigated:rainfed yield ratio: the SPAM2010 crop whose irrigated and all-rainfed yields set the ratio's level (read with read_spam_yields()), and the LPJmL crop functional type whose band yields supply its year-to-year anomaly (read with read_lpjml_regime_yield()). Items that neither source classifies get a stand-in, so every item has both sources; each *_basis column says how close the stand-in is, and rationale says why it was chosen.

The items are every row of cft_mapping and every "Primary crops" item of items_prod_full except fallow, which together hold every item that carries harvested area in build_primary_production() or in the gridded land use.

Usage

regime_yield_crop_mapping

Format

A tibble with one row per production item. Columns:

  • item_prod_code: Integer FAOSTAT item code, the join key.

  • item_prod_name: Human-readable item name, for reading only.

  • spam_crop: SPAM2010 v2.0 crop code (one of its 42, e.g. "whea"), or several joined by an operator whose meaning spam_basis fixes (see the section "Reading spam_crop").

  • spam_basis: How the SPAM crop relates to the item: "direct" (it is the item), "direct_aggregate" (SPAM itself lists the item in that multi-crop aggregate), "group_proxy" (SPAM does not list the item; the aggregate of its crop group stands in), "proxy" (a different crop stands in, e.g. grain maize for forage maize), "composite_weighted" (an area-weighted mean over several SPAM crops' ratios) or "product_dominance" (one of two SPAM crops, chosen per country).

  • lpjml_cft: LPJmL crop functional type, spelled as in cft_mapping's cft_lpjml: one of the twelve crop CFTs or "others". Equal to cft_lpjml for every item cft_mapping classifies.

  • lpjml_basis: As spam_basis, for the LPJmL CFT. Items on LPJmL's generic "others" stand are "group_proxy".

  • rationale: Why each non-direct source was chosen. The weakest stand-ins, the fodder crops, are marked WEAK.

Source

SPAM crops from Table S3 of the supplement to Yu, Q. et al. (2020). A cultivated planet in 2010 – Part 2: The global gridded agricultural-production maps. Earth System Science Data 12, 3545-3572. doi:10.5194/essd-12-3545-2020 . LPJmL crop functional types from cft_mapping. Stand-ins for the remaining items chosen by WHEP.

Reading spam_crop

The ratio meant here is the irrigated yield over the all-rainfed yield, each yield being production over harvested area. A single code is that crop's ratio. Joined codes mean one of three things:

  • + with spam_basis "direct": "pmil+smil" (millet) and "acof+rcof" (coffee). SPAM splits one FAO item in two by national shares, so the codes are pooled: harvested area and production are summed over both codes per regime, and the ratio is computed from the sums.

  • + with spam_basis "composite_weighted": the forage grasses ("whea+barl+ocer", items 638, 639, 645, 651, 996) and forage legumes ("bean+chic+cowp+pige+lent+opul+rest", items 640, 641, 643). Each code's ratio is computed on its own, and the item's ratio is the area-weighted mean of those ratios, weighted by each crop's SPAM2010 harvested area (irrigated plus rainfed) in the country, or by its global harvested area where the country grows none of them.

  • | with spam_basis "product_dominance": Linum (772) and Hemp (776), "ooil|ofib". WHEP books one harvested area for the seed (SPAM ooil) and the fibre (SPAM ofib), so one of the two is used per country: the aggregate of whichever product has the larger FAOSTAT production there.

Examples

head(regime_yield_crop_mapping)
#> # A tibble: 6 × 7
#>   item_prod_code item_prod_name spam_crop spam_basis       lpjml_cft lpjml_basis
#>            <int> <chr>          <chr>     <chr>            <chr>     <chr>      
#> 1             15 Wheat          whea      direct           temperat… direct_agg…
#> 2             27 Rice           rice      direct           rice      direct     
#> 3             44 Barley         barl      direct           temperat… direct_agg…
#> 4             56 Maize (corn)   maiz      direct           maize     direct     
#> 5             71 Rye            ocer      direct_aggregate temperat… direct_agg…
#> 6             75 Oats           ocer      direct_aggregate temperat… direct_agg…
#> # ℹ 1 more variable: rationale <chr>