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METK CASE STUDY
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Project:        SoilWise - Horizon Europe Soil Mission
Partner:        METK - Estonian Crop Research Institute (Estonia)
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, integrated production, FAIR data, EPSG:4326,
                Estonia, METK
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DESCRIPTION
-----------
Harmonized soil observation dataset from the METK (Estonian Crop Research
Institute) case study on integrated production systems in Estonia. Contains
130 soil samples standardized for interoperability according to FAIR data
principles for the SoilWise European catalogue.

SITE INFORMATION
----------------
Country         : Estonia
Partner         : METK - Estonian Crop Research Institute
Site name       : METK Integrated Production
Approximate lat : 58.73469496
Approximate lon : 26.47130506
Land use        : Integrated agricultural production
Sampling period : (insert years)
Depth sampled   : 0-20 cm

GEOSPATIAL BOUNDING BOX (for Zenodo)
-------------------------------------

  CRS   : EPSG:4326 (WGS84)

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FILES INCLUDED
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1. METK_Case_Study_Integrated_Production_fixed6.csv
   Description : Soil chemical and physical data from integrated production
                 plots monitored by METK
   Delimiter   : comma (,)
   Encoding    : UTF-8
   Rows        : 130
   Depth range : 0-20 cm

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DATA DICTIONARY - COLUMN DEFINITIONS
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Sample_ID
  Type        : Text
  Description : Unique identifier for each soil sample.

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

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

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

Latitude_EPSG4326
  Type        : Float
  Unit        : Decimal degrees (WGS84 / EPSG:4326). Positive = North.
  Description : Geographic latitude of the sampling point.

Longitude_EPSG4326
  Type        : Float
  Unit        : Decimal degrees (WGS84 / EPSG:4326). Positive = East.
  Description : Geographic longitude of the sampling point.

Clay_pct
  Type        : Float
  Unit        : % (g per 100 g soil)
  Method      : Hydrometer or pipette method (ISO 11277)
  Description : Clay fraction (< 2 µm) as percentage of fine earth.

Silt_pct
  Type        : Float
  Unit        : % (g per 100 g soil)
  Method      : ISO 11277
  Description : Silt fraction (2-50 µm) as percentage of fine earth.

Sand_pct
  Type        : Float
  Unit        : % (g per 100 g soil)
  Method      : ISO 11277
  Description : Sand fraction (50-2000 µm) as percentage of fine earth.

USDA_Classification
  Type        : Text (categorical)
  Description : USDA soil texture class. Translated from original Estonian/
                KA5 codes to English USDA vocabulary.

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.

Total_N_g_kg
  Type        : Float
  Unit        : g kg⁻¹
  Method      : Kjeldahl (ISO 11261) or dry combustion (ISO 13878)
  Description : Total nitrogen content.

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

Phosphorus_Olsen_mg_kg
  Type        : Float
  Unit        : mg kg⁻¹ (ppm)
  Method      : Olsen extraction (NaHCO₃ 0.5M, pH 8.5) — ISO 11263
  Description : Plant-available phosphorus.

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STANDARDIZATION NOTES
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- All coordinates in EPSG:4326 (WGS84 decimal degrees)
- Date format: ISO 8601 (YYYY-MM-DD); original M/DD/YYYY converted
- Decimal separator: period (.)
- Missing values: empty cell (no NA, no N/A text)
- Encoding: UTF-8
- Delimiter: comma (,)
- USDA texture classes translated from original Estonian/KA5 codes to English

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ZENODO UPLOAD CHECKLIST
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[ ] Title: "Harmonized soil observations for METK Integrated Production
            - SoilWise Project"
[ ] Creators: all authors with ORCID
[ ] Description: integrated production systems, Estonia, sampling methodology,
                 0-20 cm depth, time period
[ ] Keywords: SoilWise, Soil Mission, Horizon Europe, Estonia, METK,
              integrated production, soil organic carbon, FAIR data
[ ] License: CC-BY 4.0
[ ] Funding: Horizon Europe Grant Agreement No. (insert number)
[ ] Geographic location (Bounding Box): (insert coordinates)
[ ] 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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