DOI: 10.5061/dryad.djh9w0w4m
title: Field experimental data of crop yields, nutrient concentrations, and harvest indices from around the world

description: Estimates of cropland nutrient budgets and nutrient use efficiencies at
 national to global scales have generally relied on average nutrient
 concentrations for quantifying nutrients removed in crops and by-products.
 Calculation of crop nutrient removal requires estimates of the yield of
 crop products (e.g. grain or beans) and crop residues (e.g. straw or
 stover) and the nutrient concentration of these components. Data for
 yields of crop products are often readily available, but those of crop
 residues are not. The harvest index can be used to estimate the quantity
 of crop residue from available data on crop product yields. Nutrients
 removed in harvested crops are the major source of nutrient losses. The
 availability of more locally relevant crop coefficients can improve the
 granularity of estimates for nutrient budgets and use efficiencies.
  To aid this, field experimental data were collated for major
 crops from August 2020 to improve estimates of crop harvest index and
 nutrient concentrations of crop products and crop residues. This dataset
 contains available data from published scientific articles or theses.
 Articles were manually checked for relevant data (generally as summary
 statistics) and transferred into a standardised format. Initially, these
 articles were selected based on relevance to maize, rice, soybeans and
 wheat and for nitrogen, phosphorus, potassium and sulphur. It is
 envisioned this dataset will increase in scope over time, in terms of
 included nutrients and crops to further improve crop nutrient budgets and
 use efficiency estimates across the world.
description: <strong>Data
 acquisition</strong> Data were collated from published articles or
 theses found in scientific literature following the method described by
 Ludemann et al.
 (2022). Terms used in Ovid
 (https://ovidsp.ovid.com/), CAB Abstracts (https://www.cabdirect.org/) and Google Scholar (https://scholar.google.com/) were as follows: (nitrogen OR phosphorus OR potassium OR sulphur OR sulfur) AND ("triticum aestivum" OR wheat OR maize OR "Zea mays" OR corn OR soybean OR "Glycine max" OR rice OR "oryza sativa") AND ("nutrient concentration" OR "nutrient content").  In September 2020 this search led to over 18,000 articles. The list of articles was manually filtered to include crop product and/or crop residue nutrient concentration and/or harvest index data of relevance to maize, rice, soybeans and wheat.  Thereafter, citation alerts were continually tracked, with data from any new articles added to the combined dataset. It is envisioned that this database will be updated with data from new articles over time. In January 2025 data for Potatoes were added. Data from the articles were manually converted into a standardized Excel format (Microsoft Office, Microsoft, Redmond, Washington, USA). Where data were unavailable in the publications as tables, data were extracted from figures using the GetData Graph Digitizer software (version 2.26, http://www.getdata-g raph-digitizer.com/).  To improve interoperability, the original Excel data file was converted to a comma-delimited CSV file using R code from: https://github.com/ludemannc/meta_analysis_crop_nutrient_dryad.git and a meta-data file was created to support this file.
description: This README file was generated on 2025-01-21 by Cameron Ludemann **GENERAL
 INFORMATION** Summary_statistics_data_from_articles.csv This datafile
 combines summary statistics data from a range of articles found in the
 scientific literature related to crop harvest index and nutrient
 concentrations of crop products (e.g. beans and grain) and crop residues
 (straw and stover). Missing data are given the letters NA.
 Meta_data_Summary_statistics_data_from_articles.csv This data file
 explains what data are in each column in the
 Summary_statistics_data_from_articles.csv file. 1. Author Information A.
 Principal Investigator Contact Information Name: Cameron Ludemann
 Institution: Wageningen University and Research Address: Plant Production
 Systems, Wageningen, The Netherlands. Email:
 [cameron.ludemann@wur.nl](mailto:cameron.ludemann@wur.nl)/cameronludemann@gmail.com B. Associate or Co-investigator Contact Information Name: Achim Dobermann Institution: International Fertilizer Association Address: Paris, France. Email: [adobermann@fertilizer.org](mailto:adobermann@fertilizer.org) 2. Date of data collection (single date, range, approximate date) 2020-2023: 3. Geographic location of data collection: World wide 4. Information about funding sources that supported the collection of the data: The International Fertilizer Association funded collation of these data. **SHARING/ACCESS INFORMATION** 1. Licenses/restrictions placed on the data: CC0 1.0 2. Links to publications that cite or use the data: Ludemann, C.I, Hijbeek, R., van Loon, M., Murrell, T.S., Dobermann, A. and van Ittersum, M. (2024), Published field experimental data of crop yields, nutrient concentrations, and harvest indices from around the world., Dryad, Dataset, [https://doi.org/10.5061/dryad.djh9w0w4m](https://doi.org/10.5061/dryad.djh9w0w4m) 3. Links to other publicly accessible locations of the data: NA 4. Links/relationships to ancillary data sets: NA 5. Was data derived from another source? yes A. If yes, list source(s): Information on the primary sources of data used in Summary_statistics_data_from_articles.csv are included in the datafile. 6. Recommended citation for this dataset: Ludemann, C.I, Hijbeek, R., van Loon, M., Murrell, T.S., Dobermann, A. and van Ittersum, M. (2024), Published field experimental data of crop yields, nutrient concentrations, and harvest indices from around the world., Dryad, Dataset, [https://doi.org/10.5061/dryad.djh9w0w4m](https://doi.org/10.5061/dryad.djh9w0w4m) 7. When files are imported into coding software such as R or Python, please make sure files are imported as text, then convert text into numeric or other format. This is to overcome the issue of some software/functions incorrectly 'guessing' the wrong format for columns with a lot of missing data (see note from Aug 2024 version below). **DATA & FILE OVERVIEW** 1. Additional related data collected that was not included in the current data package: NA 2. Are there multiple versions of the dataset? Yes A. If yes, name of file(s) that was updated: Meta_data_Summary_statistics_data_from_articles.csv and Summary_statistics_data_from_articles.csv. i. Why was the file updated? An error in the Mueller et al (2019) Ref #128 was found whereby the fertilizer application rate information had not been added. This has now been rectified in the Dec 2023 version. ii. When was the file updated? December 2023 In July 2024 the file dates were updated to align to when the associated publication was published. In August 2024 an error was fixed. The error was that some columns with a lot of missing (NA) data were by default given a 'logical' format which led to a loss of information. This has been fixed in the August 2024 commit in the open github link below with new csv files created for this DRYAD repository. In January 2025 additional data were added to the dataset (potatoes) and a new column was added with data on total nitrogen uptake (CP+CR*_Up__N__Mean_kg_ha*) for the new potato data. #### Code/Software Scripts to produce these data files  are available at: [https://github.com/ludemannc/meta_analysis_crop_nutrient_dryad.git](https://github.com/ludemannc/meta_analysis_crop_nutrient_dryad.git)  **Related works** Ludemann et al. (2022) referred to some of the maize data included in this dataset. The present dataset can be used in combination with Tier 1 (global average) and Tier 2 (regional/country/sub-country average) crop harvest index and nutrient concentration data from Ludemann et al. (2023) where data are lacking. It is recommended to use the present dataset in combination with raw replicated field experiment data from [www.cropnutrientdata.net](http://www.cropnutrientdata.net). Ludemann et al. (2022) describe how both datasets can be combined. **Version changes** The December 2023 version had Mueller et al (2019) Ref #128 updated with fertilizer treatment data as originally this had not been added.  The July 2024 version had updates to github information and text file to reflect publication year. The August 2024 version had issues with formatting of some columns (with a lot of missing data) overcome. The September 2024 version had the associated article DOI linked to dataset. No changes were made to dataset. The January 2025 version had potato data added. In addition a column named CP+CR*_Up__N__Mean_kg_ha* for the new potato data  was added and an explanation of this new column was included in the meta-data file. **References** Ludemann CI, Hijbeek R, van Loon MP, Murrell TS, Dobermann A, van Ittersum MK. 2022. Estimating maize harvest index and nitrogen concentrations in grain and residue using globally available data. Field Crops Research 284: 1-25. Ludemann CI, Hijbeek R, van Loon M, Murrell ST, Dobermann A, van Ittersum MK. 2023. Global data on crop nutrient concentration and harvest indices. [https://doi.org/10.5061/dryad.n2z34tn0x](https://doi.org/10.5061/dryad.n2z34tn0x). Ludemann CI, Hijbeek R, van Loon M, Murrell ST, Dobermann A, van Ittersum MK. 2024. Tiered maize and wheat nutrient removal coefficients estimated from available data. Nutrient Cycling in Agroecosystems [https://doi.org/10.1007/s10705-024-10381-6](https://doi.org/10.1007/s10705-024-10381-6) **Acknowledgements** This project was financially supported by the International Fertilizer Association. The authors wish to acknowledge the following people who helped convert data from the literature into the standardized format: Joost Krooshof, Bert Rijk, Tobias Bader, Victoria Miles-Hildago, Marloes van Loon and Emil Löwik.