Dataset: Park Grass Hay Yields, Fertilizer and Lime Treatments 1903-1964

Citation:  Sarah Perryman (2025). Dataset: Park Grass Hay Yields, Fertilizer and Lime Treatments 1903-1964 Electronic Rothamsted Archive, Rothamsted Research, Harpenden, UK DOI : https://doi.org/10.23637/rpg5-OAyieldsperiod2-2
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Example data derived from the dataset - plot 3 (no fertilizer or manure)

Example data derived from the dataset - plot 3 (no fertilizer or manure)

Summary

In 1903, "Design Period 2", started on Park Grass. Originally one plot per treatment since 1856, in 1903, most plots (1-13) were split into two to test the effects of liming, as acidity had built up with fertilizer use. One half of each plot was limed with chalk (L) and the other half left un-limed (U). In 1920 the remaining plots (14, 15 and 17) were split in half also, to join the liming scheme. Three other plots (18, 19 and 20) were split to three to receive light lime (LL), heavy lime (HL) and un-limed (U). Yields are provided for all fertiliser treatment plots and sub-plots. Yields are expressed as t/ha at 100% dry matter. Variations in yield reflect the various fertilizer treatments and liming regimes, as well as the local weather and atmospheric inputs. This dataset contains the yields of hay (t/ha), for both the 1st and 2nd cuts, harvested from Park Grass Hay Experiment since 1903-1964. Details of the fertilizer, lime treatments and harvest dates are also included. This data set is followed by that for post-1965 data and so includes plot numbers ("subsequent plots"), and dates of introduction, from that later design-period to provide continuity between datasets.

This 2nd version incorporates corrected dates for some "start and end cut" dates. They vary slightly with the previous version by one or two days. It also includes a note about the sunny and shaded parts of the south end of plot 14 - whereby a comparison was done to establish the shading effects of a large oak tree in 1920 and from, 1924-1959. This dataset contains the averaged data of 'shaded' vs 'sunny' (the separate data is available from the e-RA database).

Also, new to this version; In 2025 a new convention for plot ID format (new_plot_id) has been introduced that enables compatibility of plot names throughout the duration of the Park Grass Experiment datasets. This has been applied retrospectively to plots and more easily communicates plot changes over time and continuity between plots in the published data. It also aim to address the Excel date problem whereby we have a number of plot names that can be auto converted to dates by Excel. The new conventions for plots divided for new fertilizer treatments uses '.' as the division separator. The new conventions for plots divided for new liming treatments uses '\' as the division separator. The traditional format is also kept in the dataset (plot_id).

Methods

This experiment tests the effects of inorganic fertilizers, organic fertilizers and soil pH (which varies on sub-plots as a result of liming) on yields of hay. See Second Design Period 1903-1964 for detail. Until 1959, the yields were estimated by cutting and weighing the whole sub-plot produce. Since 1960, yields were estimated from strips cut from the centre of each plot with a forage harvester. In the dataset, the forage harvester weight is converted using an equation from Bowley et. al and for 1960-1964, both values are provided. See Additional Information below for conversion equations.

Since 1960, after the first cut in mid-June the remainder of each plot is mown and made into hay, continuing earlier management and ensuring return of seed. For the second cut, the whole of each plot is cut with a forage harvester.

Technical Information

Hay yields have been recorded every year since the Park Grass experiment began, with the first harvest in 1856. Dried samples have also been kept since 1856 and these are preserved in the Rothamsted Sample Archive.

Related Documents

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Previous Versions

Contributors

  • Sarah Perryman: Data curator
  • Margaret Glendining: Data curator
  • Richard Ostler: Project leader
  • Nathalie Castells: Data manager
  • Chris Hall: Data collector
  • Andy Gregory: Project manager
  • Jackie Potts: Data curator

Dataset Access and Conditions

Rights Holder

Rothamsted Research

License

Creative Commons License This dataset is available under a Creative Commons Attribution Licence (4.0).

Cite this Dataset

YOU MUST CITE AS: Sarah Perryman (2025). Dataset: Park Grass Hay Yields, Fertilizer and Lime Treatments 1903-1964 Electronic Rothamsted Archive, Rothamsted Research, Harpenden, UK https://doi.org/10.23637/rpg5-OAyieldsperiod2-2

Please review our How to Credit Datasets guidance for more information.

Conditions of Use

Rothamsted relies on the integrity of users to ensure that datasets are used appropriately and Rothamsted Research receives suitable acknowledgment as being the originators of these data. Please review the Conditions of Use before downloading.

Table Of Contents

An Excel file, 02-rpg5_yields_1903-1964.xlsx, contains Park Grass fertilizer and lime treatments and the yields for the 1st and 2nd cuts. Frictionless CSV files are provided for users who prefer CSV over Excel files.

Individual plot yields are derived from the PGHAYEQUIV dataset in the e-RA database and were checked with the published yields in the annual Rothamsted Yield Books. Park Grass data 1856- was entered to the e-RA database by Jackie Potts.

In accordance with the Joint Code of Practice for Research at Rothamsted, data processing in e-RA follow rigorous standard operating procedures to ensure the quality and correctness of data collected in the field through to depositing in the e-RA database. To ensure quality control during data inputting, the data sets were typed on two separate occasions (double data entry). During the second typing (verification) the data values were compared with those typed on the earlier occasion, and any discrepancies were resolved before verification continued. This procedure also set out how to handle situations where the written records were illegible or ambiguous. This procedure avoided visual checking of data, which can be very inaccurate. Once the data were entered into e-RA, they were independently back-checked against the original data sheets.

Park Grass was initiated to investigate the ways of improving the yield of hay by the application of inorganic fertilizers and organic manure. With time, the soil became more acidic and in 1903 plots had been halved and the effects of lime tested. From 1965 a new liming regime was initiated with four sub-plots, three receiving lime to maintain soil pH (0-23cm depth) at pH 7, 6, and 5 on sub-plots a, b and c. Sub-plot d does not receive any lime. These later yields are available in the dataset 'Park Grass Hay Yields, Fertilizer and Lime Treatments 1965-2018'.

The change in harvest method in 1960 means recorded yields of dry matter are larger than previously as fewer losses occur. The previous harvest method estimated yield by weighing the produce from the whole field. The yield of a strip cut by the forage harvester at 100% dry matter, weighed immediately in the field, is used for yield value for 1960-64. The remainder of the plot is mown and made into hay in the usual way, continuing earlier management and ensuring the return of seed. Conversion equation for 1960-1964 is Yield cut 1 = 0.2743 x (YF^1.663) (See references, Bowley et al (2017).

To convert these data 1903-1964 (and also the 1856-1902 dataset) to align with the data from 1960-present, the reverse formula for Bowley's conversion equation is Yield = EXP((1/1.662)*LN(old yield/0.2743)) where LN() is the natural log function i.e loge() and EXP is the exponential function i.e. EXP(a)=ea (S. Clark, March 2025).

  • The dataset Park Grass Hay Yields, Fertilizer and Lime Treatments 1903-1964 is a published dataset from the e-RA Database. e-RA is part of the Rothamsted Long-Term Experiments - National Bioscience Research Infrastructure (RLTE-NBRI), which also covers maintenance of the Long-Term Experiments, the Rothamsted Sample Archive and Rothamsted's environmental monitoring activities including the weather stations and its role in the UK Environmental Change Network
  • The RLTE-NBRI is funded by UK Research and Innovation - Biotechnology and Biological Sciences Research Council (UKRI-BBSRC) under award BBS/E/RH/23NB0007 (2023-2028). The RLTE-NBRI is also supported by the Lawes Agricultural Trust. e-RA has been part of a National Capability since 2012, previous awards from the BBSRC were Grants BBS/E/C/00005189 (2012-2017) and BBS/E/C/000J0300 (2017-2022)
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For further information and assistance, please contact the e-RA curators, Sarah Perryman and Margaret Glendining using the e-RA email address: era@rothamsted.ac.uk