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fertilizer.frt

Purpose

fertilizer.frt lists every fertilizer product the simulation can apply, with its mass fractions of mineral nitrogen, mineral phosphorus, organic nitrogen, organic phosphorus, and the share of mineral N that is in the NH3 form. Each record fills one fertilizer_db entry in the fertdb array. Fertilizer operations (in chem_app.ops and the management decision tables) reference entries here by name.

Source

Format

  • Line 1: title (skipped).
  • Line 2: header (skipped).
  • Lines 3+: one record per fertilizer product. List-directed read into fertdb(it) (type fertilizer_db).
# Field Type Units Default Description
1 fertnm char(16) none "" fertilizer name (key referenced by chem_app.ops and management decision tables)
2 fminn real kg min-N / kg fertilizer 0.0 fraction of fertilizer that is mineral N (NO3 + NH3)
3 fminp real kg min-P / kg fertilizer 0.0 fraction of fertilizer that is mineral P
4 forgn real kg org-N / kg fertilizer 0.0 fraction of fertilizer that is organic N
5 forgp real kg org-P / kg fertilizer 0.0 fraction of fertilizer that is organic P
6 fnh3n real kg NH3-N / kg min-N 0.0 fraction of mineral N content that is NH3

The five real fractions must sum to less than or equal to 1 for a single product. fminn + fminp + forgn + forgp is the total nutrient mass per unit fertilizer; the remainder is carrier mass.

Example

First lines of refdata/Ames_sub1/fertilizer.frt:

fertilizer.frt: written by SWAT+ editor v2.2.2 on 2023-10-17 14:43 for SWAT+ rev.60.5.4
name                     min_n         min_p         org_n         org_p         nh3_n         pathogens  description
elem_n                 1.00000       0.00000       0.00000       0.00000       0.00000              null  ElementalNitrogen
elem_p                 0.00000       1.00000       0.00000       0.00000       0.00000              null  ElementalPhosphorous
anh_nh3                0.82000       0.00000       0.00000       0.00000       1.00000              null  AnhydrousAmmonia
urea                   0.46000       0.00000       0.00000       0.00000       1.00000              null  Urea
46_00_00               0.46000       0.00000       0.00000       0.00000       0.00000              null  46_00_00
18_46_00               0.18000       0.20200       0.00000       0.00000       0.00000              null  18_46_00
dairy_fr               0.00700       0.00500       0.03100       0.00300       0.99000              null  Dairy_FreshManure

Notes on the example:

  • The editor writes two trailing columns (pathogens and description) that are not in fertilizer_db. List-directed reads stop once the type is filled, so both trailing tokens are discarded by the reader. The literal null in the pathogens column has no effect.
  • For urea, fminn = 0.46 and fnh3n = 1.00. That is, 46% of the product is mineral N, and 100% of that mineral N is in the NH3 form.
  • For 18_46_00, fminn = 0.18 and fminp = 0.202. Note that the third value in the "46" position is the P (P2O5 converted to P), not P2O5 directly.

manure_db.frt

Named manure types. Each entry points to one organic-matter record in manure_om.frt and (optionally) to records for pesticides, pathogens, heavy metals, salts, and other constituents that may be carried with the manure. This is the lookup used by manure-application operations and by manure-allocation.md.

Source

Format

  • Line 1: title (skipped).
  • Line 2: header (skipped).
  • Lines 3+: one record per manure type. Two passes: count rows, then read.
# Field Type Description
1 name char(25) Manure-type name. Referenced by manure-application operations and by manure_allo.mnu.
2 org_min char(25) Crosswalk into manure_om.frt. Resolved into iorg_min.
3 pests char(25) Pesticide profile name. Pointer field ipests is reserved (the crosswalk loop is commented out in the reader). Use null when not applicable.
4 paths char(25) Pathogen profile name. Pointer ipaths.
5 hmets char(25) Heavy-metal profile name. Pointer imets.
6 salts char(25) Salt-ion profile name. Pointer isalts.
7 constit char(25) Other-constituent profile name. Pointer iconstit.
8 descrip char(80) Free-text description.

After reading each row, the reader crosswalks org_min against manure_om(:)%name and stores the matching index in manure_db(it)%iorg_min. The other crosswalks are present in the type but not wired in this reader.

Example

refdata/Osu_1hru/manure_db.frt:

manure_db.frt: manure database
name          org_min             pests  paths  hmets  salts  constit  description
beef_salt     mw_beef_liq         null   null   null   null   null     midwest_beef_liquid_salt

One manure type, pointing at mw_beef_liq in manure_om.frt. No pesticide, pathogen, heavy-metal, salt, or constituent profile.

manure_om.frt

Organic-matter attributes for each manure type. Holds the water fraction and the C, mineral N, mineral P, organic N, organic P, and NH3 fractions used when a manure application is partitioned into the soil pools.

Source

Format

  • Line 1: title (skipped).
  • Line 2: header (skipped).
  • Lines 3+: one record per manure organic-matter profile.
# Field Type Units Description
1 name char(64) none Profile name. Used as the crosswalk target from manure_db.frt.
2 frac_water real kg water / (kg manure + kg water) Water fraction of the as-applied manure.
3 fcbn real kg C / kg manure Carbon fraction.
4 fminn real kg min-N / kg manure Mineral N fraction (NO3 + NH3).
5 fminp real kg min-P / kg manure Mineral P fraction.
6 forgn real kg org-N / kg manure Organic N fraction.
7 forgp real kg org-P / kg manure Organic P fraction.
8 fnh3n real kg NH3-N / kg min-N Share of mineral N that is NH3.
9 description char(64) none Free-text description.

Example

refdata/Osu_1hru/manure_om.frt:

manure_om.frt: manure organic matter database
name            frac_water   fcbn          fminn         fminp         forgn         forgp         fnh3n  description
mw_beef_liq     0.988        0.000780576   0.000311751   0.00081295    0.002110312   0.000365707   0.99   midwest_beef_liquid
mw_beef_slur    0.926        0.016786571   0.002697842   0.00081295    0.002110312   0.000365707   0.99   midwest_beef_slurry

Two profiles. The liquid form is nearly all water (98.8%); the slurry form is 92.6% water with much higher solids and carbon.

  • chem_app.ops. Fertilizer applications in management schedules reference fertnm from fertilizer.frt or a manure name from manure_db.frt.
  • manure-allocation.md. Allocates manure from named source objects to HRUs and other receivers.
  • codes.bsn. The active carbon model (cswat) controls how N from fertilizer and manure enters the soil pools.