This readme file was generated on 2025-06-18 by Sabina Braun and provides a list and description of each file included in the dataset.

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DATASET GENERAL INFORMATION
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Title of dataset: SLU long-term field experiments: The Swedish soil fertility experiments (R3-9001), crop and soil data from 1962 and onwards
Creator(s)/Primary investigator(s): Swedish University of Agricultural Sciences
Persistent identifier of dataset: https://doi.org/10.5878/eqj9-j270
Related publication for description of project, methods etc: Carlgren, K., & Mattsson, L. (2001). Swedish soil fertility experiments. Acta Agriculturae Scandinavica, Section B-Plant Soil Science, 51(2), 49-76. 
Missing data delimiter: NA

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FILE OVERVIEW
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R39001_data.tsv
Tab-delimited numeric data corresponding to soil and crop properties from experiment. 
Relationship between files: treatments defined in R39001plot_metadata.tsv. components defined in R39001component_descriptions.tsv. variables defined in R39001variables_descriptions.tsv. units defined in R39001units_descriptions.tsv, location defined in R39001location_description.tsv

R39001plot_metadata.tsv
Tab-delimited data describing plot amendments and treatments.
Relationship between files: components defined in R39001component_descriptions.tsv. variables defined in R39001variables_descriptions.tsv. unit defined in R39001units_descriptions.tsv

R39001component_descriptions.tsv
Tab-delimited definitions of components column in R39001_data.tsv
Relationship between files: treatments defined in R39001plot_metadata.tsv. variables defined in R39001variables_descriptions.tsv. unit defined in R39001units_descriptions.tsv

R39001variables_descriptions.tsv
Tab-delimited definitions of variable column in R39001_data.tsv
Relationship between files: treatments defined in R39001plot_metadata.tsv. components defined in R39001component_descriptions.tsv. unit defined in R39001units_descriptions.tsv

R39001units_descriptions.tsv
Tab-delimited definitions of unit column in R39001_data.tsv
Relationship between files: treatments defined in R39001plot_metadata.tsv. components defined in R39001component_descriptions.tsv. variables defined in R39001variables_descriptions.tsv. 

R9001location_description.tsv


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DATA-SPECIFIC INFORMATION FOR R39001_data.tsv
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License: CC0 1.0 

Number of columns/variables: 15

Number of rows/cases: 249801

Explanation of missing/empty data: data outside of feasible values are denoted by NA. 
    
Variable list:  

variable	description
1000_part_weight	The weight of 1000 seeds
AL_K	Potassium (K) content in soil, measured by extraction with ammonium acetate lactate (AL)
AL_P	Phosphorus (P) content in soil, measured by extraction with ammonium acetate lactate (AL)
bulk_density	The bulk density of seeds
density_harvest	The percentage of gound covered by the crop by harvest
density_spring	The percentage of gound covered by the crop in spring 
gluten	The glutent content of a grain
HCl_K	Potassium (K) content in soil, measured by extraction with hydrochloric acid (HCl)
HCl_P	Phosphorus (P) content in soil, measured by extraction with hydrochloric acid (HCl)
lodging	The permanent displacement of crop stems from their vertical position as a result of stem buckling and/or root displacement
org_C	Organic carbon (C) content
part_grass	The percentage of grass coverage 
part_legume	The percentage of legume coverage
part_other	The percentage of coverage by plant other than grass or legume
pH_H2O	Soil pH measured in ultrapure water in 1:5 ratio (soil:solution, volume:volume)
protein	Amount of protein in the given component 
sugar_content	Percentage of sugar in sugar beets
sugar_yield	Amount of sugar extracted from sugar beets
tot_C	Total carbon (C) content
tot_K	Total potassium (K) content
tot_N	Total nitrogen (N) content
tot_P	Total phosphorus (P) content
yield	Total dry mass of the given component


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DATA-SPECIFIC INFORMATION FOR R39001plot_metadata.tsv
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License: CC0 1.0 

Number of columns/variables: 2

Number of rows/cases: 8

Variable list:  
	
treatment_code		Denotes treatment code, the combination of factors for the plot
factor_crop_rotation	Denotes factor crop rotation, I=system with livestock, II=system without livestock
factor_PK		Denotes four different levels of phosphorus (P) and potassium (K) addition
factor_N		Denotes four different levels of nitrogen (N) addition
livestock_manure	Denotes if the treatment recives any livestock manure


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DATA-SPECIFIC INFORMATION FOR R39001component_descriptions.tsv
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License: CC0 1.0 

Number of columns/variables: 2

Number of rows/cases: 12

Variable list:  
	component: name of component as in component column of R39001_data.tsv
	description: definition of component

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DATA-SPECIFIC INFORMATION FOR R39001variables_descriptions.tsv
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License: CC0 1.0 

Number of columns/variables: 2

Number of rows/cases: 24 

Variable list:  
	variable: name of variable as in R39001_data.tsv
	description: definition of variable

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DATA-SPECIFIC INFORMATION FOR R39001units_descriptions.tsv
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License: CC0 1.0 

Number of columns/variables: 2

Number of rows/cases: 8

Variable list:  
	unit: name of unit as in R39001_data.tsv
	description: definition of unit

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DATA-SPECIFIC INFORMATION FOR R39001location_descriptions.tsv
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License: CC0 1.0 

Number of columns/variables: 2

Number of rows/cases: 11

Variable	Description
LTE		The SLU code for the experimental serie
ID		The SLU code for the specific experimental site
Location	The name of the experimental site


