e-RA: the electronic Rothamsted Archive

Exhaustion Land Open Access Data

Exhaustion Land yields (spring barley and winter wheat) and assorted crop & soil phosphate (P) data, 1974-2008

Download the Data

This dataset is presented as a downloadable Excel Spreadsheet containing all available data variables:

Exhaustion Land yields (spring barley and winter wheat) and all crop and soil P data.xlsx

or csv file; Exhaustion Land yields (spring barley and winter wheat) and all crop and soil P data.csv

Publication Date

Publication date V1. 2018/12/16
Last updated V1. 2018/12/12

Access Use and Conditions

Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License.

To use this data and metadata please cite as follows in your publications: Rothamsted Research (2018). Exhaustion Land Yields and P data 1974-2008. Electronic Rothamsted Archive https://doi.org/10.23637/ex4-oadata-001-01

Rothamsted relies on the integrity of users to ensure that Rothamsted Research receives suitable acknowledgement as being the originators of these data. This enables us to monitor the use of each dataset and to demonstrate their value. Please send us a link to any publication that uses this Rothamsted data.


This dataset contains data from the long-term Exhaustion Land experiment at Rothamsted Research, specifically grain and straw yields (spring barley to 1991, thereafter winter wheat), % phosphorous (P) and P uptake (1976-2008), soil Olsen P (plant available P) and Total P (1974-2008) from the long-term Exhaustion Land experiment (established 1856) at Rothamsted Research. The experiment as a whole underwent five different phases of treatment (see below). This data is from that half of the experiment, established in 1986, called the 'P Test' which tested the effects of different levels of plant available P on crop yields and P uptake. It also contains data from the preceding 10/12 years.

Prior to the 'P test', fertilizer N was applied. This had increased yields and allowed the crop to take greater advantage of the P and K residues remaining in the soil from an earlier phase (Phase I) of the experiment. These were initially large but declined as amounts of phosphate in the soil declined. In Phase IV, from 1986, because the P residues had been exhausted it was decided to see how quickly this decline in soil fertility could be reversed - annual cumulative dressings of P as triple phosphate were tested (four different rates on four sub-plots) and spring barley grown - this is known as the 'P test'. Basal N & K were applied so that was not limited. Yield responses to available-P were rapid and showed that above a critical level on this soil, of about 10-12 mg kg P there is no further increase in yield. No P was applied between 1993-1999. Maintenance dressings of P have been applied since 2000 (but not to the P0 sub-plots).


Rothamsted Research, Harpenden, Hertfordshire, England, AL5 2JQ, UK.
51.813 N 0.376 W 128 m asl. Grid reference TL121 139.

The Hoosfield and Exhaustion Land aerial photo indicates the postion of the Exhaustion Land within Hoosfield.

Hoosfield and Exhaustion Land aerial photo.


Soil classification: Survey of England & Wales Series - Batcombe-Carstens Series
Soil description: Silty clay loam topsoil over clay-with-flints (Avery & Catt, 1995).
Soil texture 0-23cm: Sand 28 %; Silt 52 %; Clay 20 % (Poulton et al, 2013).
Soil pH: Soils are maintained at pH 7 or above.


The Exhaustion Land experiment was started in 1856 on a site on the northern edge of Hoosfield. It has progressd through various phases . This open access dataset shows analyses from part of Phase III and Phase IV (the P build-up phase), in bold below;

Phases of experiment:


Harvest years

Description of treatment



No fertilizers or manures

Phase I


Annual applications of N, P, NPK, or nil; FYM from 1876-1901.

Phase II


No fertilizers or manures

Phase III


Basal N



Four rates of N and treatments rotated

Phase IV


Plots split and four rates of P applied ‘P Test’. Basal N&K



No P. Basal N&K



Maintenance P. Basal N&K

Phase V


Maintenance P. Basal N&K

*1975 Fallow

Exhaustion land overview of Phases

Please refer to the following plans and treatment details when using the data:

Summary plot and sub-plot layout and P applications as triple superphosphate in build-up phase 1986-1992:

Plots 2, 4, 6, 8, 10 Not relevant to P Tests data

Plot 9
Sub-plot 091
131 kg P

Plot 7
Sub-plot 071
131 kg P

Plot 5
Sub-plot 051
131 kg P

Plot 3
Sub-plot 031
131 kg P

Plot 1
Sub-plot 011
131 kg P

Plot 9
Sub-plot 092
87 kg P

Plot 7
Sub-plot 072
87 kg P

Plot 5
Sub-plot 052
87 kg P

Plot 3
Sub-plot 032
87 kg P

Plot 1
Sub-plot 012
87 kg P

Plot 9
Sub-plot 093
44 kg P

Plot 7
Sub-plot 073
44 kg P

Plot 5
Sub-plot 052
44 kg P

Plot 3
Sub-plot 033
44 kg P

Plot 1
Sub-plot 013
44 kg P

Plot 9
Sub-plot 094

Plot 7
Sub-plot 074

Plot 5
Sub-plot 052

Plot 3
Sub-plot 034

Plot 1
Sub-plot 014

Exhaustion Land plan & fertilizer treatments Phase III 1940-85 (pdf)
Exhaustion Land plan & fertilizer treatments Phase IV 1986-92 (pdf)
Exhaustion Land plan & fertilizer treatments Phase IV 1993-99 (pdf)
Exhaustion Land plan & fertilizer treatments Phase IV 2000-06 (pdf)
Annual P & K inputs 1986 onwards (pdf)


1856-1875 winter wheat;
1876-1901 potatoes;
1902-1991 spring barley most years , fallow in 1920, 1967 and 1975;
1992 onwards winter wheat, except in 2001 when a failed crop was resown with spring wheat.


Crop yields grain and straw yields were determined at 85% dry matter

Soil sampling Samples were taken from the topsoil (0-23 cm), usually in autumn. 16-20 cores were taken with a 2.0 cm diameter semi-cylindrical auger using a random zigzag pattern up and down the length of each sub-plot. Using the known soil weight of topsoil, Olsen P, in mg P/kg, can be converted to kg P/ha to relate changes in the amount of Olsen P to the amount of P removed from the soil (Johnston et al., 2016). A range of Olsen P concentrations were established between 1856 and 1901 when P was added as fertilizer or in FYM. Following a long period of ‘exhaustion’, different rates of P were applied to subplots between 1986 and 1992, and ‘maintenance’ dressings have been applied since 2000. However, some sub-plots have received no fresh P since 1901 or 1856. Before the 1980s soils were only sampled occasionally, since then they have been sampled every two or three years. For those years when the soil was not sampled, the crop response to plant-available P was correlated with the average Olsen P data from the years before and after.

Plant-available 'Olsen' P is determined by the Olsen method, (Olsen et al., 1954). Air dried soils (2mm)  are extracted with 0.5M NaHCO3, buffered at pH 8.5. Extracts are analysed colourimetrically using the Technicon AAII segmented continuous flow analyser. Data for 1985 and 1992 calculated; for P3, P2 & P1 plots in 1992 a linear increase between 1989 & 92 is assumed; P0 plots are mean of 1991 & 93. Plots 031 in 1993, 032 in 1996, and 072 in 1999 & 2001 are repeat analyses.

Total soil P was sampled as half-plots in 1974; equivalent to current sub-plots 1&2 and 3&4; re-analysed by Aqua regia in 2008. It is determined by fusion with NaCO3 (Mattingly, 1970) and analysed colourimetrically (modified Murphy and Riley, molybdenum blue) on the Technicon AAII segmented flow analyser, or by Aqua Regia digestion (McGrath & Cunliffe, 1985). Digested solutions are analysed using a Perkin Elmer Optima - Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Note: The data is very limited, in 1974 the soil samples were taken from half-plots rather than the quarter-plots that were introduced in 1976.

% P in grain and straw is determined by dry ashing (Piper, 1942) using a muffle furnace at 450-500 ºC. Solutions were analysed colourimetrically using  the modified Murphy and Riley, molybdenum blue method on the Technicon AAII segmented flow analyser.  P, K, Ca, Mg and Na were determined using automated Atomic Absorption (AA). Since 1975 these have been done using ICP-OES analyses.

P uptake in grain and straw were calculated from the crop yield at 100% dry matter and %P in the grain and straw.


For more detail on the phases of the Exhaustion Land experiment see the Exhaustion Land main page

The grain yield and Olsen P data was used to investigate the relationship between plant-available P and yield in Poulton, P. R., Johnston, A. E. and White, R. P. (2013).

The Olsen P data was also used to look at the decline in available P after P applications stop (Johnston et al., 2016).

Details of the experiment from 1852-1975 can be found in Johnston, A. E. and Poulton, P. R. (1977); including a summary of the amounts of P and K applied in fertilizer and/or manure and removed by the crops.

For information on the Rothamsted site and the long-term experiments see the 'Guide to the classical and other long-term experiments, datasets and sample archive' (2018) and 'The soil at Rothamsted' (1995).

Provenance & Quality

The data contained in this spreadsheet are derived from data measured at Rothamsted Research, Harpenden. Please contact the e-RA Curators for further details.


Exhaustion Land
Crop yield
Phosphate fertilizers
Soil fertility
Long-term experiments


Paul Poulton, Andy Macdonald, Sarah Perryman, Margaret Glendining.


Rothamsted Research.

Further Information and contact details

Please contact the e-RA Curators for further information, and assistance with questions about the data or its interpretation:

e-RA Curators,
Department of Computational and Analytical Sciences (CAS)
Rothamsted Research
Harpenden, Herts, AL5 2JQ

email: era@rothamsted.ac.uk


The Long-term Experiments and weather stations are supported by the Lawes Agricultural Trust and BBSRC National Capability Funding (BBS/E/C/000J0300) recognising the national and international importance of the data.

Key References:







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