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TUM CASE STUDY
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Project:        SoilWise - Horizon Europe Soil Mission
Partner:        TUM - Technical University of Munich (Germany)
Grant Agreement: (insert Grant Agreement number)
Prepared by:    (insert author names and ORCID)
Date:           2026-04-30
License:        Creative Commons Attribution 4.0 International (CC-BY 4.0)
                https://creativecommons.org/licenses/by/4.0/
Keywords:       SoilWise, Soil Mission, Horizon Europe, soil organic carbon,
                soil texture, CO2 land initiative, Novasoil, FAIR data,
                EPSG:4326, Germany, Bavaria, TUM
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DESCRIPTION
-----------
Harmonized soil observation dataset from the TUM (Technical University of
Munich) CO2 LAND Initiative case study in Bavaria, Germany. Contains 305
soil samples collected across agricultural sites in Bavaria. Data standardized
for interoperability according to FAIR data principles for the SoilWise
European catalogue.

SITE INFORMATION
----------------
Country         : Germany
Region          : Bavaria
Partner         : TUM - Technical University of Munich
Project         : CO2 LAND Initiative / Novasoil
Approximate lat : ~48.18°N
Approximate lon : ~9.45°E
Land use        : Agricultural (arable land, Bavaria region)
Sampling period : (insert years)
Depth sampled   : 0-20 cm

GEOSPATIAL BOUNDING BOX (for Zenodo)
-------------------------------------
  North : 48.20
  South : 48.15
  East  : 9.50
  West  : 9.40
  CRS   : EPSG:4326 (WGS84)

  Note: Original coordinates were stored as integers (lat × 10000, lon × 1000)
  and have been converted to decimal degrees during harmonization.

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FILES INCLUDED
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1. TUM_Case_Study_CO2_LAND_Initiative_fixed2.csv
   Description : Soil chemical and physical data from the CO2 LAND Initiative
                 monitoring network across Bavaria, Germany. Collected under
                 the Novasoil project (CO2_land_Novasoil_ID).
   Delimiter   : semicolon (;)
   Encoding    : UTF-8
   Rows        : 305
   Depth range : 0-20 cm

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DATA DICTIONARY - COLUMN DEFINITIONS
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Sample_ID
  Type        : Text
  Description : Unique sample identifier derived from original field
                CO2_land_Novasoil_ID codes.

Soil_Sampling_Date
  Type        : Date (ISO 8601: YYYY-MM-DD)
  Description : Date of soil sampling. Original format DD/MM/YYYY converted
                to ISO 8601.

Upper_Depth_cm
  Type        : Integer
  Unit        : cm
  Value       : 0 (all samples)
  Description : Upper boundary of the sampled soil layer.

Lower_Depth_cm
  Type        : Integer
  Unit        : cm
  Value       : 20 (all samples)
  Description : Lower boundary of the sampled soil layer.

Latitude_EPSG4326
  Type        : Float
  Unit        : Decimal degrees (WGS84 / EPSG:4326). Positive = North.
  Description : Geographic latitude. Converted from original integer format
                (raw_lat / 10000 → decimal degrees, e.g. 481759 → 48.1759°N).

Longitude_EPSG4326
  Type        : Float
  Unit        : Decimal degrees (WGS84 / EPSG:4326). Positive = East.
  Description : Geographic longitude. Converted from original integer format
                (raw_lon / 1000 → decimal degrees, e.g. 9455 → 9.455°E).

Nitrogen_N_pct
  Type        : Float
  Unit        : % (g per 100 g soil)
  Method      : Dry combustion (ISO 13878)
  Description : Total nitrogen content as percentage.

Phosphorus_mg_kg
  Type        : Float or text
  Unit        : mg kg⁻¹
  Method      : (see original TUM documentation)
  Description : Phosphorus content. Values prefixed with '<' indicate below
                detection limit (e.g., '<0.44' means < 0.44 mg kg⁻¹).

Potassium_K_mg_kg
  Type        : Float
  Unit        : mg kg⁻¹
  Method      : Ammonium acetate extraction or aqua regia digestion
  Description : Potassium content.

Magnesium_Mg_mg_kg
  Type        : Float
  Unit        : mg kg⁻¹
  Description : Magnesium content.

pH
  Type        : Float
  Unit        : pH units (dimensionless)
  Method      : Potentiometry in water suspension (1:2.5), ISO 10390
  Description : Soil reaction. Range: 3.5-9.5.

Organic_Matter_pct
  Type        : Float
  Unit        : % (g per 100 g soil)
  Method      : Loss on ignition or calculated as SOC × 1.724
  Description : Soil Organic Matter content as percentage.

CN_ratio
  Type        : Float
  Unit        : dimensionless
  Description : Carbon-to-Nitrogen ratio.

USDA_Classification
  Type        : Text (categorical)
  Description : USDA soil texture class. Translated from original German KA5
                texture codes to English USDA vocabulary:
                  sL   → Sandy loam
                  uL   → Silt loam
                  tL   → Clay loam
                  lS   → Loamy sand
                  lT   → Clay
                  hhL  → Silt loam
                  (etc.)

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STANDARDIZATION NOTES
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- All coordinates in EPSG:4326 (WGS84 decimal degrees)
  Original format: integer (lat × 10,000; lon × 1,000); converted to decimal
- Date format: ISO 8601 (YYYY-MM-DD); original DD/MM/YYYY converted
- Decimal separator: period (.); 1930 comma decimal values corrected
- Missing values: empty cell (no NA, no N/A text)
- Encoding: UTF-8
- Delimiter: semicolon (;)
- USDA texture classes translated from German KA5 codes to English
- One value in Phosphorus_mg_kg: '<0,44' corrected to '<0.44'

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ZENODO UPLOAD CHECKLIST
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[ ] Title: "Harmonized soil observations for TUM CO2 LAND Initiative
            (Bavaria) - SoilWise Project"
[ ] Creators: all authors with ORCID
[ ] Description: CO2 LAND Initiative, Novasoil, Bavaria Germany, 305 samples,
                 0-20 cm depth, arable land, sampling methodology, time period
[ ] Keywords: SoilWise, Soil Mission, Horizon Europe, Germany, Bavaria, TUM,
              CO2 LAND Initiative, Novasoil, soil organic carbon, FAIR data
[ ] License: CC-BY 4.0
[ ] Funding: Horizon Europe Grant Agreement No. (insert number)
[ ] Geographic location (Bounding Box): N 48.20, S 48.15, E 9.50, W 9.40
[ ] Upload this README alongside the CSV files
[ ] After publication: verify DOI via SoilWise portal

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END OF README
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