Dataset: Park Grass Fertilizer Treatments and Hay Yields 1856-1902

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Summary

This dataset contains the fertilizer treatments and yields of hay (t/ha), for both the 1st and 2nd cuts, harvested from Park Grass Hay Experiment since its inception in 1856 to 1902, "Design Period 1" (In 1903, "Design Period 2" started on Park Grass when but in 1903, when most plots were split into two to test the effects of liming, as acidity had built up in the soil with fertilizer use during Period 1). The experiment was originally one plot per treatment since 1856 and yields are provided for all fertiliser treatment 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 variables such as the weather and atmospheric inputs). This data set is followed by that for Design Period 2, 1903-1964, and so includes plot numbers ("subsequent plots"), and dates of introduction, from that later design-period to provide continuity between datasets.

Park Grass was initiated to investigate the ways of improving the yield of hay by the application of inorganic fertilizers and organic manure. The fertilizer tests were made of farmyard manure, N, P, K, Mg, Na, Si, as well as sawdust and straw, in various combinations and amounts (fishmeal and poultry manure were not tested until the early 20th century).

As the experiment progressed, it was observed that the soil became more acidic and in 1903 plots were halved and the effects of lime tested - therefore this dataset ends in 1902. The next dataset is Design Period 2, 1903-1964 (see Related Datasets below). However, note that in 1881 Lawes and gilbert started investigating the effects of lime applications to small parts of the northern edge of some of the plots. In 1883 the west halves of plots received burnt lime, then in 1887 the eastern halves received burnt lime. These early tests of lime on yields are not included in this dataset but are available from the e-RA database. Notes made by Lawes & Gilbert and staff at that time are available in the "Rothamsted White Books". Therefore, note that all parts of every plot, even the un-limed sublots of Design Period 2 and the sub-plot d's of Design Period 3, received lime once in their history, although this was a small amount over >138 years ago.

Methods

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. The plots were originally cut by scythe, then by horse-drawn and then tractor-drawn mowers. The mowing machine was first used for the first cut in 1901, though it had been used for the second cut since 1881. The plots were cut each year for hay, usually in June, and a second cut taken in the autumn since 1875. A second cut was not taken every year, and not from every plot each year, if there was insufficient herbage to sample. No second cut taken 1856-1874, 1876, 1884, 1885, 1887, 1899, 1911, 1914, 1921, 1924, 1933 or 2003. In 1903-1917, the second cut was taken from the whole plot, not the Limed and Un-limed halves. The regrowth after the first cut was grazed by sheep 1856-1872, except for 1866, 1870, and 1873 and 1874, when the regrowth was mown but not removed from the plots.

Yields were originally estimated by weighing the produce from the whole plot, either as hay (1st harvest) or green crop (2nd harvest), and dry matter determined. Since 1960, yields of dry matter have been estimated from strips cut with a forage harvester.

Technical Information

Conversion Factor - Change in harvesting method in 1960: When comparing these plot yields to later yields after 1960 a conversion factor is recommended due to a change in harvesting method in 1960 which has resulted in recorded yields of dry matter being larger than previous harvest method, as fewer losses occur. The previous harvest method to 1959 was estimated yield by weighing the produce from the whole field. Since 1960, the yield of a strip cut by the forage harvester at 100% dry matter (two per plot), weighed immediately in the field, is used for yield value for 1960-64 and post-1965, see next datasets. A conversion equation for 1960-1964, to match pre-1960 yields, is Yield cut 1 = 0.2743 x (YF^1.663) (See references, Bowley et al (2017).

In 2025 a new convention for plot ID format (new_plot_id) was introduced to enable 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 aims to address the Excel date problem whereby a number of plot names that can be auto-converted to dates by Excel. The new conventions for plots split for fertilizer modifications 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).

Related Documents

• Park Grass Experiment lime treatments 1856-2021 :
• Silvertown et al. (2006) The Park Grass Experiment 1856 - 2006: its contribution to ecology :
• Jenkinson et al. (1994) Trends in herbage yields over the last century :
• Bowley et al. (2017) Historical trends in iodine and selenium in soil and herbage at ark Grass :
• Park Grass Plot & Treatments Timeline 1856-2025 :
• Park Grass experiment plan and treatments 1856-1902 :

Related Datasets

• Park Grass Changes in Mean Species Numbers 1864-2011
• Park Grass Species, Fertilizer and Lime Treatments 1991-2000
• Park Grass Hay Yields, Fertilizer and Lime Treatments 1903-1964
• Park Grass Species, Fertilizer and Lime Treatments 2010-2012
• Park Grass Hay Yields, Fertilizer and Lime Treatments 1965-2023

Contributors

• Sarah Perryman: Data curator
• Margaret Glendining: Data curator
• Richard Ostler: Project leader
• Nathalie Castells: Data manager
• Andy Gregory: Project manager
• Jackie Potts: Data curator
• Paul Poulton: Related person
• Andrew Macdonald: Related person
• Rodger White: Project member
• Suzanne Clark: Project member

Dataset Access and Conditions

Rights Holder

Rothamsted Research

License

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

Cite this Dataset

YOU MUST CITE AS: Perryman, S., Glendining, M. (2025). Dataset: Park Grass Fertilizer Treatments and Hay Yields 1856-1902 Electronic Rothamsted Archive, Rothamsted Research, Harpenden, UK https://doi.org/10.23637/rpg5-PGYields1856-1902-1

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