Park Grass

Local identifier
Years operational
To study the effects of organic and inorganic amendments and lime on old grass for hay
Started by Lawes and Gilbert in 1856, its original purpose was to investigate ways of improving the yield of hay by the application of inorganic fertilisers or organic manures. Within 2-3 years it became clear that these treatments were having a dramatic effect on the species composition of what had been a uniform sward comprising about 50 species. Dramatically different swards have evolved as a result of the different pH and nutrient status of the soils. There are 35-45 species on the unfertilised plots but only 2 or 3 species on some of the fertilised plots. The continuing effects on species diversity and on soil function of the original treatments, together with later tests of liming and interactions with atmospheric inputs and climate change, has meant that Park Grass has become increasingly important to ecologists and soil scientist. The plots are cut for hay in mid-June. The first cut for hay ensures seeds are returned each year. The management of the aftermath following the first hay cut varied in the early years, either being grazed by sheep or cut green. Since the 1890s the second crop has been cut green and removed. In some years a third cut has also been taken The experiment includes a small area used for micro-plot experiments.
Farm operation data?
Sample archive?
Samples available?
Data Access Statement
Available to any researcher on request
Data license
Data URL
Data policy
Yes (not online)
Rothamsted Research
research organisation
Environmental Change Network
research organisation
Dr Sarah Perryman
data manager
Rothamsted Research
Computational and Analytical Sciences
Dr Jon Storkey
principal investigator
Rothamsted Research

Site: Park Grass

research station field
United Kingdom
Geographic location
51.803812, -0.372097
© OpenStreetMap contributors
133 Metres
Visits permitted?
Visiting arrangements
By arrangement with Dr Andy Macdonald
The experiment was established on c. 2.8 ha of parkland that had been in permanent pasture for at least 100 years.
Soil type
Soil description
Silty clay loam over clay-with-flints overlying chalk. The site is normally well drained (Hook series) or moderately well drained (Batcombe series)
Soil properties
VariableDepthValue (range)UnitsRef yearEstimated?Baseline?
sand content 11.6 Percent
silt content 66.3 Percent
clay content 22.1 Percent
soil density0 – 23 Centimetres1.1 gram per cubic centimetre2011
Climatic type
temperate oceanic climate

Design period: First period (1856—1902)

CropYears grown
nitrogen fertilizer exposure
Plot application: Whole plot
N1  (52 kgN/ha)
Chemical form: ammonium sulfate
N2  (104 kgN/ha)
Chemical form: ammonium sulfate
N3  (156 kgN/ha)
Chemical form: ammonium sulfate
N1*  (52 kgN/ha)
Chemical form: ammonium nitrate
N2*  (104 kgN/ha)
Chemical form: ammonium nitrate
natural fertilizer exposure
Plot application: Whole plot
farmyard manure
Application frequency: once every 4 years
fish meal
Application frequency: once every 4 years
To supply 68 kgN/ha.
superphosphate exposure
Plot application: Whole plot
P  (36 kgP/ha)
potassium fertilizer exposure
Plot application: Whole plot
K  (242 kgK/ha)
Chemical form: potassium sulphate
sodium nutrient exposure
Plot application: Whole plot
Na  (17 kgNa/ha)
Chemical form: sodium sulphate
magnesium nutrient exposure
Plot application: Whole plot
Mg  (12 kgMg/ha)
Chemical form: magnesium sulphate

Design period: Second period (1903—1964)

Design description
In 1903 plots 1-13, (except 5/1, 5/2, 6 and 12) and 16 were halved and the effects of regular applications of lime (as CaCO3) were tested. FYM, applied every four years, was re-introduced on three plots (13, 19 and 20) in 1905. In 1920, three more plots (14, 15 and 17), were halved and plots 18, 19 and 20 were divided into 3 subplots to test lime.
CropYears grown

Design period: Third period (1965—)

The botanical composition of the plots has been studied by visual surveys and by looking at the percentage contribution of the various species to the hay harvested. Chemical analyses of the crops and soils have been made and physical samples of the crops and soils preserved.
Design description
In 1965 most plots were divided into four sub-plots, three of which receive chalk to maintain pHs of 7, 6 and 5 (sub-plots a, b and c respectively). The fourth sub-plot (sub-plot d) receives no chalk and the pH of these ranges from 3.5 to 5.7 depending on the fertilizer treatment. From 1965 plots 5/1, 5/2 and 6 were used for microplot experiments. Plots 6a and 6b were re-included in the main experiment in 1972 but the other half of plot 6 (6c and 6d) and plots 5/1 and 5/2 have remained outside the main experiment. Since 1990, nitrogen fertilizer has been withheld from half of all sub-plots formerly receiving 96 kg N ha-1 (plots 9 and 14) as either ammonium sulphate or sodium nitrate to study processes controlling soil acidification, heavy-metal mobilisation and botanical changes. Since 1995, plot 13 has been split into 13/1 and 13/2 and FYM/Fishmeal withheld from plot 13/1. Since 1996 plot 2 has been split into 2/1 and 2/2 with plot 2/1 receiving K as potassium sulphate. In 2013 plot 7 (PKNaMg) was divided into two equal sized plots, 7/1 and 7/2. This was to test whether P fertilizer was still required, because large reserves of P have built up in the soil. No P fertilizer was applied to Plot 7/1, but K, Na and Mg applications continued. Plot 7/2 continued as before (i.e. it received PKNaMg). In addition, N applications began on plot 15; 144kg N/ha as sodium nitrate to provide a comparison with plot 11/1 which receives the same amount of N as ammonium sulphate together with P, K, Na & Mg. From autumn 2016 all plots previously receiving 35 kg P ha-1 as triple superphosphate will receive 17 kg P ha-1 (until further notice) because of the high levels of available soil P from past P inputs. The P application to plot 20 will remain unchanged. Current K, Mg and Na rates on Park Grass remain unchanged.
CropYears grown

Related publications

  • J. Storkey , A.J. Macdonald , J.R. Bell , I.M. Clark , A.S. Gregory , N.J. Hawkins , P.R. Hirsch , L.C. Todman and Whitmore, A. P. (2016) "The Unique Contribution of Rothamsted to Ecological Research at Large Temporal Scales.", Advances in Ecological Research (eds: A.J. Dumbrell , R.L. Kordas and G. Woodward), Vol 55, Chapter 1, pp. 3-42
  • Storkey, J. , Macdonald, A. J. , Poulton, P. R. , Scott, T. , Kohler, I. H. , Schnyder, H. , Goulding, K. W. T. and Crawley, M. J. (2015) "Grassland biodiversity bounces back from long-term nitrogen addition", Nature , 528, 401-4
  • Silvertown, J. , Poulton, P. R. , Johnston, A., E. , Edwards, G. , Heard, M. and Biss, P. M. (2006) "The Park Grass Experiment 1856-2006: Its contribution to ecology", Journal of Ecology, 94, 801-814