Broadbalk

  • Experiment Code: R/BK/1
  • Experiment Site: Rothamsted
  • Objectives: To test the effect of different organic manures and inorganic fertilizers on the yield of winter wheat.
  • Description: Started in 1843, Broadbalk is one of the oldest continuous agronomic experiments in the world. Wheat is grown every year on all or part of the experiment. Established to test the effects of various combinations of inorganic fertilizers (N, P, K, Na and Mg) and organic manures on the yield of winter wheat, many of these treatments continue today. A control strip has received no fertilizer or organic manures since 1843. It was started by Lawes and Gilbert in autumn 1843, and the first crop was harvested in summer 1844.
  • Date Start: 1843
  • Establisment Period End: 1851
  • Date End: Ongoing

Key Contacts

  • Andy Macdonald

  • Role: Principal Investigator
  • Organisation: Rothamsted Research
  • Address: West Common, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
  • Sarah Perryman

  • Role: Data Manager
  • Organisation: Rothamsted Research
  • Address: West Common, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
  • Margaret Glendining

  • Role: Data Manager
  • ORCID: https://orcid.org/0000-0002-6466-4629
  • Organisation: Rothamsted Research
  • Address: West Common, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom

Funding

Experimental Design

Description

  • The experiment was divided into different Strips or 'Plots' (2 - 20) receiving the different fertilizer and manure treatments each year. Most treatment strips were established by 1852, except for strip 2a (2.1), which began in 1885, and strip 20, which began in 1906. Plot 19 was originally a half plot, and became its current size in 1904. Between 1894 and 1925 many plots were harvested in two halves, Top (T) and Bottom (B), equivalent to the Western and Eastern parts of the experiment.

Design

  • Period: 1852 - 1925
  • Number of Blocks: 19
  • Number of Replicates: 1
  • Number of Harvests per Year: 1

Crops

Crop Years Grown
Winter Wheat

Factors

Factors are the interventions or treatments which vary across the experiment.

Nitrogen Fertilizer Exposure

Description: Inorganic nitrogen fertilizer in various forms and amounts applied annually

Application: Whole Plot

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
N1 48 kgN/ha 1852 - 1925 winter wheat broadcast application method ammonium sulfate All applied in autumn, 1852-1877, all applied in spring 1878-1883; 24 kgN applied in autumn, remainder applied in spring 1884-1925
N1* 48 kgN/ha 1852 - 1925 winter wheat broadcast application method sodium nitrate All applied in spring, as one application until 1898, as two equal amounts 1899-1925
N1. 5 72 kgN/ha 1852 - 1878 winter wheat broadcast application method ammonium sulfate Applied to Plot 19 with rape cake, All applied in autumn
N2 96 kgN/ha 1852 - 1925 winter wheat broadcast application method ammonium sulfate All applied in autumn, 1852-1877, all applied in spring 1878-1883; 24 kgN applied in autumn, remainder applied in spring 1884-1925, except to strip 15. Strip 15 N applied in spring 1873-77, N applied in autumn 1878-1925.
N2* 96 kgN/ha 1852 - 1925 winter wheat broadcast application method sodium nitrate All applied in spring, as one application until 1898, as two equal amounts 1899-1925
N3 144 kgN/ha 1852 - 1925 winter wheat broadcast application method ammonium sulfate All applied in autumn, 1852-1877, all applied in spring 1878-1883; 24 kgN applied in autumn, remainder applied in spring 1884-1925
N4 192 kgN/ha 1852 - 1864 annually winter wheat broadcast application method ammonium sulfate All applied in autumn

Fym Exposure

Description: FYM from cattle

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
Farmyard Manure 35 t/ha 1843 - 1925 Annual winter wheat Applied to plot 2b (2.2) from 1843, and to plot 2a (2.1) since 1885. Plot 2a was a new plot made in 1885. FYM is applied in autumn, supplying approx 225 kgN

Phosphate Fertilizer Exposure

Description: phosphate fertilizer

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
P 35 kg/ha 1843 - 1925 annually winter wheat chemical basal application triple superphosphate Applied in the autumn, omitted 1915

Potassium Fertilizer Exposure

Description: Potassium fertilizer application

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
K 90 kg/ha 1843 - 1925 annually winter wheat fertilizer basal application potassium sulphate Applied in the autumn, omitted 1915, 1917-1919

Sodium Nutrient Exposure

Description: sodium fertilizer application

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
Na 16 kg/ha 1843 - 1925 annually winter wheat fertilizer basal application sodium sulphate Applied in the autumn, omitted 1915

Magnesium Nutrient Exposure

Description: Magnesium fertilizer application

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
Mg 11 kg/ha 1843 - 1925 annually winter wheat fertilizer basal application magnesium sulphate Applied in the autumn, omitted 1915

Rapeseed Cake Exposure

Description: Organic manure supplying approx 96 kgN

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
C 96 kgN/ha 1852 - 1926 annually winter wheat Supplying approx 96 kg N (N2).

Factor Combinations

Factor Combinations are the combination of factors applied to different plots on the experiment.

Factor Combination Time Coverage Notes
FYM 1885 - 1925 Applied to plot 2a (2.1), which was created in 1885.
FYM 1843 - 1925 Applied to plot 2b (2.2), originally called plot 2, named plot 2b in 1885 when plot 2a was created.
Nil 1843 - 1925 Strip 3. Originally 2 half plots, 3 (nil since 1844) and 4 (1844-51 NP; since 1852 nil). Harvested separately until 1899. Strip 16 received nil 1865-1883
PKNaMg 1843 - 1925 Strip 5
N1 PKNaMg 1843 - 1925 Strip 6
N2 PKNaMg 1852 - 1925 Strip 7, also Strip 15a 1852-1872, Strip 15 1873-1925, but N applied at different times to strip 7. Strip 15 was divided into 15a and 15b which received different fertilizer treatments until 1873.
N3 PKNaMg 1852 - 1925 Strip 8
N1* PKNaMg 1894 - 1925 Strip 9, split into 9a and 9b, 1852-1893 receiving different treatments. 9a received N1*/N2* plus PKNaMg, 9b received only N2*/N1*.
N4 PKNaMg 1852 - 1864 Strip 16, which then received nil 1865-1883 and N2*PKNaMg since 1884
N2* PKNaMg 1884 - 1925 Strip 16; previously received N4 PKNaMg (1852-1864) and nil (1865-1883)
N1.5 PKNaMg +C 1852 - 1872 Strip 15b. After 1872 strip 15a and 15b combined and received the same fertilizer treatments N2 PKNaMg

Measurements

Variable Unit Collection
Frequency
Material Description Crop
Yield Components t/ha annually SpecifiedCrop Grain and straw yields at field moisture content. Actual dry matter not measured, assumed to be approximately 85% dry matter. winter wheat
Weight per Bushel Dressed Corn lb annually SpecifiedCrop Bushel weights can be used to derive Hectolitre weights (HLWT),a measure of grain quality. winter wheat
Soil Organic Carbon % infrequently Soil Topsoil (0-23cm) from soil sampled in 1865, 1881, 1893 and 1914.
Soil Organic Carbon t/ha infreqently Soil Topsoil (0-23cm) from soil sampled in 1865, 1881, 1893 and 1914. Calculated from % SOC and soil bulk density; adjusted for changes in bulk density in strips given FYM
Soil Total Nitrogen % infrequently Soil Topsoil (0-23cm) from soil sampled in 1865, 1881, 1893 and 1914.
Plant Available Phosphorous mg/kg infrequently Soil Sodium bicarbonate soluble P (Olsen P). Topsoil (0-23cm) from soil sampled in 1865, 1881, 1893 and 1914.
Soil Bulk Density g/cm3 infrequently Soil A single mean value for all plots which do not receive FYM and estimated values for plots which receive FYM, based on measurements made in 1865, 1881, 1893 (Dyer, 1902), 1914 (unpublished) and 2000 (Watts et al, 2006).
Harvest Date annually SpecifiedCrop Includes both cutting and carting date, ie dates crop cut and then removed from the field. winter wheat

Description

  • 19 fertilizer treatment strips divided into five sections in 1926 (I-V) crossing all the treatment strips. In 1955 Section I was divided into Ia and Ib; Ia in continuous wheat, no fallow, Ib continued in the fallow rotation. In 1955 Section V was divided into Va and Vb. Va continued in the fallow rotation, with no herbicides applied. Vb received lime in 1955, and became continuous wheat with no further fallows from 1959.

Design

  • Period: 1926 - 1967
  • Number of Blocks: 19
  • Number of Sub-plots:
  • Number of Harvests per Year: 1

Crops

Crop Years Grown
Winter Wheat
Fallow

Factors

Factors are the interventions or treatments which vary across the experiment.

Nitrogen Fertilizer Exposure

Description: Inorganic nitrogen fertilizer in various forms and amounts applied annually

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
N1 48 kg/ha 1926 - 1967 twice winter wheat broadcast application method ammonium sulfate 24kgN applied in autumn, remainder in spring
N2 96 kg/ha 1926 - 1967 twice winter wheat broadcast application method ammonium sulfate 24kgN applied in autumn, remainder in spring
N3 144 kg/ha 1926 - 1967 twice winter wheat broadcast application method ammonium sulfate 24kgN applied in autumn, remainder in spring
N1* 48 kg/ha 1926 - 1967 twice winter wheat broadcast application method sodium nitrate Applied in spring as two equal amounts
N2* 96 kg/ha 1926 - 1967 twice winter wheat broadcast application method sodium nitrate Applied in spring as two equal amounts

Fym Exposure

Description: FYM from cattle

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
Farmyard Manure 35 t/ha 1926 - 1967 Once a year winter wheat Applied to strips 2.1 (2a) and 2.2 (2b). Not applied in the fallow years

Factor Combinations

Factor Combinations are the combination of factors applied to different plots on the experiment.

Factor Combination Time Coverage Notes
FYM 1926 - 1965

Measurements

Variable Unit Collection
Frequency
Material Description Crop
Yield Components t/ha annually SpecifiedCrop Grain and straw yields at field moisture content, approximately 85% dry matter. winter wheat
Weight per Bushel Dressed Corn lb annually SpecifiedCrop Bushel weights can be used to derive hectolitre weights (HLWT), a measure of grain quality winter wheat
Soil Organic Carbon % infrequently Soil Topsoil (0-23cm) from soil sampled in 1936; 1944 and 1966.
Total Soil Nitrogen % infrequently Soil Topsoil (0-23cm) from soil sampled in 1936; 1944 and 1966.
Plant Available Phosphorous mg/kg infrequently Soil Sodium bicarbonate soluble P (Olsen P). Topsoil (0-23cm) from soil sampled in 1936, 1944 and 1966
Soil Bulk Density g/cm3 infrequently Soil A single mean value for all plots which do not receive FYM and estimated values for plots which receive FYM, based on measurements made in 1865, 1881, 1893 (Dyer, 1902), 1914 (unpublished) and 2000 (Watts et al, 2006).
Soil Organic Carbon t/ha infrequently Soil Topsoil (0-23cm) from soil sampled in 1936, 1944 and 1966. Calculated from % SOC and soil bulk density; adjusted for changes in bulk density in strips given FYM
Weed Species Richness Species occurence, selected plots and selected years for all sections (before herbicides were applied)
Harvest Date annually SpecifiedCrop Both cutting date and carting date (ie date crop removed from field) winter wheat

Description

  • Two major modifications were made from 1968: i) The division of Sections I to V to create 10 new Sections (0 - 9), so the yield of wheat grown continuously could be compared with that of wheat grown in rotation after a two-year break. ii) The introduction of modern, short-strawed cultivars, which lead to an increase in grain yields and a decrease in straw yields. The old cultivar Squarehead's Master was grown on parts of some plots between 1987 and 1990, enabling a comparison to be made with modern cultivars After the 1968 changes, Sections 0, 1, 8 and 9 continued to grow winter wheat only, whilst Sections 2, 4, 7 and Sections 3, 5, 6 went into two different 3-course rotations (see 1968 cropping details link). In 1978, Section 6 reverted to continuous wheat and the other five Sections went into a five year rotation. Pesticides are applied where necessary, except on Section 6, which does not receive spring or summer fungicides. Herbicides have been used as required since 1964 on all of the experiment, except for Section 8 (old Section VA), which has never received herbicides. On Section 0 the straw on each plot has been chopped after harvest and incorporated in the soil since autumn 1986; on all other Sections the straw is baled and removed. In 1993 Section 9 was re-drained so that water leaching through the soil could again be collected and analysed. Lime has been applied as required since the 1950s to maintain soil pH at a level at which crop yield is not limited. From 2001 P has not been applied to some plots until levels of plant available P decrease to more appropriate agronomic levels. This is reviewed each year.

Design

  • Period: 1968 - Now
  • Number of Harvests per Year: 1

Crops

Crop Years Grown
Winter Wheat1968 -
Oats1996 -
Spring Beans1968 - 1978
Potatoes1968 - 1996
Winter Beans2018 -
Fallow
Maize1997 - 2017

Crop Rotations

Rotation Crops
continuous wheat (1968 - ) Winter Wheat
P-BE-W (1968 - 1979) Potatoes > Spring Beans > Winter Wheat
F-W-W (1968 - 1981) Fallow > Winter Wheat > Winter Wheat
F-P-W (1979 - 1983) Fallow > Potatoes > Winter Wheat
F-P-W-W-W (1982 - 1999) Fallow > Potatoes > Winter Wheat > Winter Wheat > Winter Wheat
O-M-W-W-W (1996 - 2017) Oats > Maize > Winter Wheat > Winter Wheat > Winter Wheat
W-W-O-W-Be (2018 - ) Winter Wheat > Winter Wheat > Oats > Winter Wheat > Winter Beans

Factors

Factors are the interventions or treatments which vary across the experiment.

Nitrogen Fertilizer Exposure

Description: N was applied as calcium ammonium nitrate (Nitro-chalk) between 1968 and 1985. Between 1968-1996 N was applied at the same rate to beans and potatoes. Between 1996-2017 oats did not receive N. Since 2018 Oats receive N at half the normal rate. Between 1997-2017 split N treatments were applied twice to the seedbed and post-emergence.

Application: Whole Plot

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
N1 48 kgN/ha 1968 - annually in mid-April winter wheat Applied to wheat, maize, spring beans, since 2018 oats at half rate. Not applied to fallow or beans from 2018.
N2 96 kgN/ha 1968 - annually in mid-April winter wheat ammonium nitrate
N3 144 kgN/ha 1968 - annually in mid-April winter wheat ammonium nitrate
N4 192 kgN/ha 1968 - annually in mid-April winter wheat ammonium nitrate
N5 240 kgN/ha 1985 - annually in mid-April winter wheat ammonium nitrate
N6 288 kgN/ha 1985 - annually in mid-April winter wheat ammonium nitrate
N1+1+1 144 kgN/ha 2001 - mid-March, mid-April, Mid-May winter wheat ammonium nitrate N2+1 for maize
N1+2+1 192 kgN/ha 2001 - mid-March, mid-April, Mid-May winter wheat ammonium nitrate N2+2 for maize
N1+3+1 240 kgN/ha 2001 - mid-March, mid-April, Mid-May winter wheat ammonium nitrate N2+3 for maize
N1+4+1 288 kgN/ha 2001 - mid-March, mid-April, Mid-May winter wheat ammonium nitrate N2+4 for maize

Potassium Fertilizer Exposure

Application: Whole Plot

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
K 90 kgK/ha 1968 - annually in autumn potassium sulphate
K2 180 kgK/ha 2001 - 2005 annually in autumn potassium sulphate
K* 90 kgK/ha 2001 - Annually in autumn potassium chloride

Phosphate Fertilizer Exposure

Application: Whole Plot

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
P 35 kgP/ha 1968 - Annually in autumn calcium bis(dihydrogenphosphate)

Sodium Nutrient Exposure

Application: Whole Plot

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
Na1 16 kgNa/ha 1968 - 1973 Annually in autumn sodium sulphate
Na2 55 kgNa/ha 1968 - 2000 Annually in autumn sodium sulphate 57 kgNa/ha until 1973

Magnesium Nutrient Exposure

Application: Whole Plot

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
Mg 12 kgMg/ha 1968 - Annually in autumn magnesium sulphate 11kgMg until 1973. 35 kgMg every 3rd year 1974-2000.
Mg2 24 kgMg/ha 2001 - 2005 Annually in autumn magnesium sulphate Plus 60 kg Mg in autumn 2000 only
Mg* 30 kgMg/ha 1968 - 2000 Annually in autumn magnesium sulphate 31kgMg as magnesium sulphate until 1973

Farmyard Manure Exposure

Description: From cattle

Application: Whole Plot

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
Fym 35 t/ha 1968 - Annually in autumn winter wheat Derived from cattle. Not applied to beans from 2018, not applied to oats 1996-2017.
Residual Fym 2001 - Plots previously receiving FYM

Castor Meal Exposure

Application: Whole Plot

Levels
Level Name Amount Years Frequency Crop Method Chemical Form Notes
C 96 kgN/ha 1968 - 1988
Residual C - Plots previously receiving

Factor Combinations

Factor Combinations are the combination of factors applied to different plots on the experiment.

Factor Combination Time Coverage Notes
FYM N2 PK 1968 - 1984 Applied to strip 01
FYM N4 PK 1985 - 2000 Applied to strip 01
(FYM) N4 2001 - Applied to strip 01
FYM N2 1968 - 2004 Applied to strip 2.1
FYM N3 2005 - Applied to strip 2.1
FYM 1968 - Applied to strip 2.2
Nil 1968 - No organic or inorganic amendments, strip 03
(P)K(Na)Mg 1968 - 1973 Applied to strip 05
N1 (P)K(Na)Mg 1968 - Applied to strip 06
N2 (P)K(Na)Mg 1968 - Applied to strip 07 and applied to strip 16 until 1984
N3 (P)K(Na)Mg 1968 - Applied to strip 08, and applied to strip 15 until 1984
N4 (P)K(Na)Mg 1968 - Applied to strip 09
N2 1968 - 2000 Applied to strip 10
N4 2001 - Applied to strip 10
N2 P 1968 - 2000 Applied to strip 11
N4 PMg 2001 - Applied to strip 11
N2 PNa 1968 - 2000 Applied to strip 12
N1+3+1 (P)K2Mg2 2001 - 2005 Applied to strip 12. P was not applied in this period
N1+3+1 (P)KMg 2006 - Applied to plot 12
N2 PK 1968 - 2000 Applied to plot 13
N4 PK 2001 - Applied to strip 14
N2 PKMg* 1968 - 2000 Applied to plot 14
N4 PK* 2001 - Applied to strip 14
N5 (P)KMg 1985 - Applied to strip 15
N6 (P)KMg 1985 - Applied to plot 16
N2 1/2[PK(Na)Mg 1968 - 1984 Applied to strips 17 and 18 in alternate years
N[0|1]+3 1/2[PKMg] 1985 - 2000 Applied to strips 17 and 18 in alternate years
N1+4+1 PKMg 2000 - Applied to strip 17
N1+2+1 PKMg 2001 - Applied to strip 18
C 1968 - 1988 Applied to strip 19
N1+1+1 KMg 2001 - Applied to strip 19
N2 K(Na)Mg 1968 - 2000 Applied to strip 20
N4 KMg 2000 - Applied to strip 20

Measurements

Variable Unit Collection
Frequency
Material Description Crop
Yield Components t/ha annually AllCrops Grain and straw at 85% dry matter.
Hectolitre Grain Weight annually SpecifiedCrop Since 1999 selected plots only winter wheat
Thousand Grain Weight annually SpecifiedCrop Since 1974 selected plots only winter wheat
Weed Species Richness annually Section 8 only (no herbicides)
Soil Organic Carbon every five years from 1987 Soil Topsoil (0-23cm)
Soil Total Nitrogen every five years from 1987 Soil Topsoil (0-23cm)
Plant Available Phosphorous mg/kg every five years for 1987 Soil Topsoil (0-23cm).
Soil Bulk Density Soil A single mean value for all plots which do not receive FYM and estimated values for plots which receive FYM, based on measurements made in 1865, 1881, 1893 (Dyer, 1902), 1914 (unpublished) and 2000 (Watts et al, 2006).
Nutrient Content annually AllCrops Selected plots since 1968 % N, P, K, Ca, Mg, Na and S. Grain and straw.
Take-all Disease Incidence annually SpecifiedCrop Selected plots since 1968. Also eyespot, sharp eyespot and brown foot rot. winter wheat
Harvest Date annually AllCrops Sowing and harvest dates of all crops
Earthworm Abundance occasional Selected plots, occasional years.

Site: Broadbalk - Rothamsted

  • Experiment Site: Rothamsted
  • Description: The site has probably been occupied since Roman times, and the Rothamsted map of 1623 shows the site under arable cultivation. The first experimental crop was harvested in 1844 after a rotation of turnips (dunged) 1839, barley 1840, peas 1841, wheat 1842 and oats 1843. The last four crops being entirely unmanured. The field was therefore considered to be exhausted according to contemporary practice.
  • Management: The site is managed using conventional tillage and pesticide applications are applied as necessary, except for herbicide and fungicide exclusion plots. There is no irrigation. The plough layer (0-23 m) is limed when necessary to maintain a minimum soil pH of 7.0 – 7.5.
  • Visit Permitted?: Yes
  • Visiting Arrangments: Contact Dr Andy Macdonald
  • Elevation: 130 Metres
  • Geolocation:    51.80946, -0.37301

Soil

  • Type: Luvisol
    The soil is classified as a Chromic luvisol. The soil texture is described as clay loam to silty clay loam over clay-with flints. The soils contain a large number of flints and are slightly calcareous. Below about 2m depth the soil becomes chalk. The experiment is under-drained and the site is free draining. There is considerable variation in soil texture across the site, with clay contents ranging from 19 – 39%

Soil Properties

Variable Value Reference Year Is Estimated Is Baseline
Sand content 25% (Percent) NO NO
Silt content 50% (Percent) NO NO
Clay content 25% (Percent) NO NO
Soil organic carbon 1% (Percent) 1843 YES NO
Total soil nitrogen 0.11% (Percent) 1843 YES NO
Plant available phosphorous (Olsen P) 10mg/kg (milligram per kilogram) 1843 YES NO
Soil bulk density 1.25g/cm3 (gram per cubic centimetre) 1843 YES NO
Soil organic carbon 28.8t/ha (tonnes per hectare) YES NO

Datasets available

Crop yield data

Broadbalk mean long-term winter wheat yields
Crop yield data Mean long-term winter wheat yields from selected treatments on Broadbalk 1852-2016, reflecting the improved treatments and agronomic practices introduced on Broadbalk such as modern cultivars, better control of pests, diseases and weeds, especially since the 1960s.
OAWWYields
Broadbalk Wheat Experiment mean annual grain and straw yields 1852-1925
Crop yield data Mean annual grain and straw yields for each treatment strip of the Broadbalk Wheat Experiment, 1852-1925. Also other agronomic information, including sowing and harvest dates, amount, type and date of application of treatments, and winter wheat cultivars.
YIELD852925
Fisher 1921 Broadbalk wheat grain yields 1852-1918
Crop yield data This dataset consists of annual wheat yields from selected plots of the Broadbalk Wheat Experiment, 1852-1918, as used by R. A. Fisher in his 1921 paper 'Studies in crop variation'.
FISHER1921

Crop nutrient data

Broadbalk Crop Nutrient Content, Wheat 1968-2017
Crop nutrient data From 1968 Broadbalk was divided into 10 sections. Grain and straw from selected sections and plots were collected and stored in the Sample Archive. They were analysed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na) and sulphur (S).
BKNUTRW

Disease data

Broadbalk Wheat Experiment brown foot rot (Fusarium spp.) 1992-2009
Disease data This dataset contains scores of Brown Foot Rot (BFR) caused by _Fusarium_ spp. , from the Broadbalk wheat experiment, with associated grain yield at harvest, 1992-2009. BFR infection varied a lot from year to year, possibly due to variation in winter and spring temperature and rainfall.
BKBFR

Soil data

Broadbalk soil organic carbon content 1843-2015
Soil data Long-term changes in soil organic carbon content (t/ha) in selected treatments of the Broadbalk experiment, where winter wheat has been grown every year since autumn 1843. SOC in t/ha, calculated from %SOC and soil weights, adjusted for changes in soil bulk density in FYM treatments.
BKSOC1843
Broadbalk Soil Total % Nitrogen Content, 1843-2010
Soil data Long-term changes in total % nitrogen concentration in the topsoil (0-23 cm) in selected treatments of the Broadbalk experiment, where winter wheat has been grown most years since 1843 (continuous wheat).
Nitro1843
Broadbalk changes in Olsen P in top soil, 1843-2010
Soil data Summary data showing changes in plant-available phosphorus (Olsen P) in the topsoil (0-23cm) of selected plots of the Broadbalk Wheat experiment, 1843-2010.
OAOlsenP1844

Species observation data

Cirsium arvense frequency on Broadbalk Section 8 1991-2018
Species observation data This dataset consists of the relative frequencies of Cirsium arvense (Creeping thistle) of the Family Asteraceae recorded on Section 8 plots of the Broadbalk Wheat Experiment, 1991-2018. Section 8 has not received any herbicides in its history.
CIRSIUM1991
Additional data is available through e-RAdata. Please register for access.

More about Broadbalk

Plans and treatments:
Experimental plans, fertilizer treatments and cropping details, 1852-present
Disease surveys:
Information about the wheat root and stem diseases assessed (take-all, eyespot, sharp eyespot and brown foot rot)
Weeds surveys:
Information about the weed surveys on Section 8 (no herbicides), 1991-present, and earlier surveys on the whole experiment, 1933-1979.
Crop nutrient content:
Information about analytical methods for crop macro nutrient content (% N, P, K, Ca, Mg, Na and S)
Grain quality assessment:
Description of what grain quality data is available (TGWs, Hagberg falling number, Hectolitre weights, grain size categories), and analytical methods used
Soil physical properties and site details:
Site details, plot area, soil moisture and drainage, soil description and texture and soil weights
Soil chemical properties:
Details of which soil chemical properties have been measured, analytical methods used and soil sampling methods
Wheat yield background information:
Description of harvest methods and datasets available
Other crops and fallow:
Description of potatoes, oats, beans and forage maize crops grown on Broadbalk, and the management of the fallow
Earthworms:
Information about earthworm measurements on Broadbalk
See a Video on the Broadbalk Experiment

Broadbalk Weeds

The Broadbalk experiment was started in 1843 to investigate the relative importance of different plant nutrients (N, P, K, Na, Mg) on grain yield of winter wheat. Weeds were controlled initially by hand hoeing and fallowing, but since 1964, herbicides have been applied to the whole experiment with the exception of Section 8. This is one of the few arable sites in the country where herbicides have never been applied. Weed surveys have been carried out annually in two phases, the first between 1933-1979 and the second from 1991-present day. There are earlier records too, with the first plot-by-plot surveys of weed species done in 1869 recording the presence of 23 species in stubble in September. Since then, approximately 130 weed species have been recorded on Broadbalk Section 8, but many of these only occur sporadically and about 30 of these are currently recorded annually (Species list 1869-2018). This site also provides an invaluable reserve for seven nationally rare or uncommon species including corn cleavers (Galium tricornutum), corn buttercup (Ranunculus arvensis), shepherd’s needle (Scandix pecten-veneris) and prickly poppy (Papaver argemone). This is now the only location in the UK where corn cleavers is known to occur naturally (see below). This resource and associated data enables various weed investigations including weed population ecology, studies on the effects of fallowing on the weed seed bank, seed dormancy and persistence, agroecology, and population dynamics of individual weed species. Recently, molecular approaches have been used to study the genetic diversity of weeds found on Section 8, this rare herbicide-free arable plot.

Section 8 was fallowed in 2015 and 2016 so there is no data for these years.

Current Survey 1991 to present

The current weed survey was started on Section 8 in 1991 and has continued annually ever since - although not on years when that section is in fallow i.e. 1994, 2001, 2008, 2015 & 2016. It was fallowed in 2015 and 2016 in order to reduce an infestation of Rumex obtusifolius in particular (see table below). Section 8 (called section VA 1958-1967) was created in 1968 when the experiment was divided into its present layout (Broadbalk plan today). The current assessment method records the presence of individual weed species in 25 random quadrats (0.1m2) per plot. Each year all 18 plots are surveyed meaning 450 quadrats are assessed per year, usually in June. Frequencies refer to the total number of quadrats in which a weed is recorded, the maximum being 25 per plot and 450 across all plots in the section. This method is more appropriate for detecting long-term trends in weed frequencies and population differences between plots than the earlier surveys (below) and provides a comprehensive set of 20 years of data for weed studies.

Galium tricornutum Section 8 Broadbalk
Corn cleavers

(Galium tricornutum) in Broadbalk

Non-herbicide plot section 8 Broadbalkp
Weeds species in Broadbalk

non-herbicide Section 8 in early summer

Broadbalk elevated view
Elevated view of Broadbalk

Section 8 weeds, mid-view, in late summer

Galium tricornutum Section 8 Broadbalk
Corn buttercup

Ranunculus arvensis

Non-herbicide plot section 8 Broadbalkp
Shepherd's needle

Scandix pecten-veneris

Broadbalk elevated view
Field poppy

Papever rhoeas

Data is presented in e-RA as the following datasets:

BKWEEDS_SUM: A summary of annual total frequencies for section 8 1991-present.

BKWEEDS_PLOT: Annual frequencies of each species per plot for section 8 1991-present.

There have been 53 species recorded in total since 1991 [species list 1991-2018] but on average there are 31 species found per year (with a maximum of 38 in 1993 & 1995 and a minimum of 26 in 2009) and there has been a gradual slight decline over the period. The long dataset allows general, overall trends to be observed and weed species are seen to differ greatly in their response to a given set of conditions, some declining, some increasing and others fluctuating - for example a decline in Papaver rhoeas between 1999 and 2003, and subsequent recovery (for which there is no obvious explanation). Of the species currently recorded annually ten species are locally common on many plots: Blackgrass (Alopecurus myosuroides), field poppy (Papaver rhoeas), common vetch (Vicia sativa), parsley-piert (Aphanes arvensis), scentless mayweed (Tripleurospermum inodorum), shepherd's needle (Scandix pectin-veneris), chickweed (Stellaria media), venus's looking glass (Legousia hybrida), creeping thistle (Cirsium arvense) and black medic (Medicago lupulina). A principal components analysis of the 1991-2002 survey data for 15 species showed clearly the influence of inorganic N fertiliser levels on the frequency of individual species. The frequency of one species (common chickweed (Stellaria media)) was greatly favoured by increasing amounts of nitrogen fertiliser from 0 to 288 kg N ha-1, others were strongly disadvantaged (e.g., black medic (Medicago lupulina) and horsetail (Equisetum arvense)), some were slightly disadvantaged (e.g., common vetch (Vicia sativa) and parsley-piert (Aphanes arvensis)), and some showed little response to differing N rates (e.g., blackgrass (A. myosuroides) and poppy (P. rhoeas)) (Moss et. al 2004).

Corn cleavers (Galium tricornutum) is one of the rarest plants in the UK and this occurence on Broadbalk is the last known site in the UK. Numbers have increased from under five individuals in the 1990's to over 450 in 2011 and this has been a consequence of our active management strategy.

The commonest species on Broadbalk:

20-year* mean frequency (max = 450 quadrats) for 19 species occurring in a mean minimum of 20 quadrats

Rank
Species listed in order of frequency
(20 yr mean)
20 year mean
1991 - 2013
2014
frequency
2014
as % of 20 yr mean
1
Alopecurus myosuroides
448
450
100
2
Papaver rhoeas
341
351
103
3
Vicia sativa
270
347
129
4
Aphanes arvensis
260
163
63
5
Tripleurospermum inodorum
257
249
97
6
Scandix pecten-veneris
180
191
106
7
Stellaria media
155
300
194
8
Legousia hybrida
125
72
57
9
Cirsium arvense
117
124
106
10
Medicago lupulina
101
61
60
11
Veronica persica
83
79
95
12
Polygonum aviculare
83
20
24
13
Equisetum arvense
81
59
72
14
Odontites verna
73
36
49
15
Ranunculus arvensis
69
64
93
16
Viola arvensis
53
1
2
17
Veronica arvensis
39
18
46
18
Minuartia hybrida
22
23
105
19
Rumex obtusifolius
20
97
469

* 20 years of records taken over 23 years (not in those years when section 8 was fallow i.e. 1994, 2001 and 2008)

Galium tricornutum Section 8 Broadbalk
Meadow vetchling

Lathyrus pratensis

Non-herbicide plot section 8 Broadbalkp
Horsetail

Equisetum arvense

Broadbalk elevated view
Chickweed

Stellaria media

Galium tricornutum Section 8 Broadbalk
Dwarf spurge

Euphorbia exigua

Non-herbicide plot section 8 Broadbalkp
Black medick

Medicago lupilina

Broadbalk elevated view
Common vetch

Vicia sativa

Earlier surveys 1933-1967 and 1968-1979

Annual surveys were conducted from 1933 to 1979. Originally, there were no sections on Broadbalk, just long strips the length of the whole field (Broadbalk plan 1852-1926). In 1926 the field was divided into 5 sections (I-V) (Broadbalk plan 1926). The whole field length was sampled for weeds as no herbicide weed control took place, just fallowing every five years. This gave all plot and section combinations (between 90 and 129 plots per year). After 1968, it was divided in to ten sections (Broadbalk plan 1996-2017) and again the whole field was surveyed each year - enabling comparison of weeds with and without herbicides.

This appears to be an excellent resource, however, it has not been widely used, principally because of the inconsistent frequency categories used. Neither were quadrats used, rather the assessor walked in a zig-zag pattern along the plot noting all weeds within 45cm of the plot boundary. Consequently there is a limitation on the interpretation of the data for ecological studies. The codes used to indicate species presence and abundance (termed STATE in the database) include the following:

0 Occasional
0+ Between 0 and T
T Distributed
T+ Between T and P
P Plentiful
P+ Between P and PP
PP Very plentiful
PP+ Between PP and PPP
PPP Extremely plentiful

The following datasets are available:

BBKWEEDS_FAL for 1933-67 (FAL indicating fallow) - herbicides applied from 1964 to all sections except VA (which became section 8 in 1968). Data for all sections and all plots.

BBKWEEDS_ROT for 1968-79 (ROT indicating rotation with other crops, though not on section 8 which is rotated only with fallow): - herbicides applied throughout to all sections except 8. Data for all sections and all plots.

During these years, surveys were conducted twice yearly, usually in May and August (sometimes as early as April or as late as September). Supplementary surveys were done for special purposes such as for blackgrass which is not obvious in the early season surveys and become more obvious in the summer when flowering. It is recommended that you extract both STATE and SPEC_REMARK since the presence of a species may be indicated by a remark such as 'patch' even though there is no code for the state. In view of the large number of null values it is probably best to tick the checkbox for STATE and exclude 'null' and '-', meaning none. In these datasets, dates are termed START DAY rather than year, as there are two surveys each year.

There were 114 species names recorded during 1933-1967 [species list 1933-1967] and 113 species names during the 1968-79 surveys [species list 1968-79].

Earlier surveys - data not included in e-RA:

Originally, there were no sections on Broadbalk, just long strips the length of the whole field (Broadbalk plan 1852-1926). The first plot-by-plot list of weed species was done in 1869 and recorded the presence of 25 species in stubble in September [species list 1869] (Thurston, 1969). Hand weeding and hoeing was practiced but due to the shortage of labour during the 1914-18 war the field became very weedy. Between 1926-1929 the field was fallowed to eliminate weeds, three out of five sections fallowed for 2 years running (Broadbalk plan 1926-1966). From 1931 a regular cycle of fallowing 1 year in five was introduced and the effect of fallow on weed seeds was studied (Brenchley & Warington 1930). Routine plot-by-plot surveys were started in 1930 and made twice yearly; first in May after spring germinating weeds are large enough to identify without trampling the crop and secondly, after the crop is cut and harvested which showed late germinating species.

Further information and references

The review paper by Moss et al. (2004) provides the most recent summary of weed studies on Broadbalk. The Thurston (1969) report provides additional information on the earlier surveys. References in both papers provide comprehensive coverage of other studies. For more details, refer to the Rothamsted Guide to the Classical Experiments 2018 pages 15-16 or contact the e-RA Curators.

Acknowledgements: With thanks to Stephen Moss, Jon Storkey, Richard Hull and Graham Shephard (VCU) for help with compiling images and data.

Note on herbicides: Applied to section 1A from 1957; to VB from 1963; and to all other sections (except VA which became section 8 in 1968) from 1964.

Notes on species: These include records of volunteer plants such as potatoes and both names for species names which have changed.

List of Latin and common names of species in current Broadbalk Survey.

Galium tricornutum Section 8 Broadbalk
Groundsel

Senecio vulgaris

Non-herbicide plot section 8 Broadbalk
Plot 3 Section 8 Broadbalk

Broadbalk elevated view
Plot 21 Section 8 Broadbalk

Key References

2021

  • Le Coeur, C. , Storkey, J. and Ramula, S.(2021) "Population responses to observed climate variability across multiple organismal groups", Oikos, 130, 476-487
    DOI: 10.1111/oik.07371
  • Storkey, J. , Mead, A. , Addy, J. and Macdonald, A.(2021) "Agricultural intensification and climate change have increased the threat from weeds", Global Change Biology, 00, 1-10
    DOI: 10.1111/gcb.15585

2018

  • Metcalf, H. , Milne, A. E. , Hull, R. , Murdoch, A. J. and Storkey, J.(2018) "The implications of spatially variable pre-emergence herbicide efficacy for weed management", Pest Management, 74, 755-765
    DOI: 10.1002/ps.4784
  • Storkey, J. and Neve, P.(2018) "What good is weed diversity?", Weed Research, 58, 239-243
    DOI: 10.1111/wre.12310

2014

  • Garcia De Leon, D. , Storkey, J. , Moss, S. R. and Gonzalez-Andujar, J. L.(2014) "Can the storage effect hypothesis explain weed co-existence on the Broadbalk long-term fertiliser experiment?", Weed Research, 54, 445-456
    DOI: 10.1111/wre.12097

2010

  • Storkey, J. , Moss, S. R. and Cussans, J. W.(2010) "Using Assembly Theory to Explain Changes in a Weed Flora in Response to Agricultural Intensification", Weed Science, 58, 39-46
    DOI: 10.1614/ws-09-096.1

2004

  • Moss, S. R. , Storkey, J. , Cussans, J. W. , Perryman, S. a. M. and Hewitt, M. V.(2004) "The Broadbalk long-term experiment at Rothamsted: what has it told us about weeds?", Weed Science, 52, 864-873
    DOI: 10.1614/WS-04-012R1

2000

1969

1964

  • Thurston, J. M.(1964) "Weed studies in winter wheat", Proceedings of the 7th British Weed Control Conference Vol. II, 592-598

1958

  • Warington, K.(1958) "Changes in the Weed Flora on Broadbalk Permanent Wheat Field During the Period 1930-55", Journal of Ecology, 46, 101-113

1945

  • Brenchley, W. E. and Warington, K.(1945) "The influence of periodic fallowing on the prevalence of viable weed seeds in arable soil", Annals of Applied Biology, 32, 285-296

1936

  • Brenchley, W. E. and Warington, K.(1936) "The weed seed population of arable soil. III. The re-establishment of weed species after reduction by fallowing", Journal of Ecology, 24, 479-501
  • Warington, K.(1936) "The effect of constant and fluctuating temperature on the germination of the weed seeds in arable soil", Journal of Ecology, 24, 185-204

1933

  • Brenchley, W. E. and Warington, K.(1933) "The weed seed population of arable soil. II. Influence of crop, soil and methods of cultivation upon the relative abundance of viable seeds.", Journal of Ecology, 21, 103-127

1930

  • Brenchley, W. E. and Warington, K.(1930) "The weed seed population of arable soil. I. Numerical estimation of viable seeds and observations on their natural dormancy", Journal of Ecology, 18, 235-272

1924

  • Warington, K.(1924) "The influence of manuring on the weed flora of arable land", Journal of Ecology, 12, 111-126

Key References

2021

  • Glendining, M. J. and Poulton, P. R.(2021) "Broadbalk Wheat Experiment plan and cropping 1852-1925", Electronic Rothamsted Archive, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
    DOI: 10.23637/rbk1-sup-1534342858-02
  • Rothamsted_Research(2021) "Broadbalk Wheat Experiment plan and cropping 1926-1967", Electronic Rothamsted Archive, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
    DOI: 10.23637/rbk1-plan1926-67-02
  • Rothamsted_Research(2021) "Broadbalk Wheat Experiment plan and cropping 1968-2017", Electronic Rothamsted Archive, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
    DOI: 10.23637/rbk1-plan1968-2017-01
  • Rothamsted_Research(2021) "Broadbalk Wheat Experiment plan and cropping since 2018", Electronic Rothamsted Archive, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
    DOI: 10.23637/rbk1-today2018-02
  • Addy, J. W. G. , Ellis, R. H. , Macdonald, A. J. , Semenov, M. A. and Mead, A.(2021) "The impact of weather and increased atmospheric CO2 from 1892 to 2016 on simulated yields of UK wheat", J. R. Soc. Interface, 18, 20210250
    DOI: 10.1098/rsif.2021.0250
  • Rothamsted_Research(2021) "Broadbalk Wheat Experiment cropping 1843-2021", Electronic Rothamsted Archive, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
    DOI: 10.23637/rbk1-crop1843-2021-01

2020

  • Addy, J. W. G. , Ellis, R. H. , Macdonald, A. J. , Semenov, M. A. and Mead, A.(2020) "Investigating the effects of inter-annual weather variation (1968-2016) on the functional response of cereal grain yield to applied nitrogen, using data from the Rothamsted Long-Term Experiments", Agricultural and Forest Meteorology, 284, 107898
    DOI: 10.1016/j.agrformet.2019.107898
  • Machtoldt, J. , Piepho , H.-P. , Honermeier, B. , Perryman, S. , Macdonald, A. and Poulton, P.(2020) "The effects of cropping sequence, fertilization and straw management on the yield stability of winter wheat (19862017) in the Broadbalk Wheat Experiment, Rothamsted, UK", The Journal of Agricultural Science, 158, 6579
    DOI: 10.1017/S0021859620000301

2018

  • Johnston, A. E. and Poulton, P. R.(2018) "The importance of long-term experiments in agriculture: their management to ensure continued crop production and soil fertility; the Rothamsted experience. ", European Journal of Soil Science, 69, 113-125
    DOI: 10.1111/ejss.12521
  • Rothamsted_Research(2018) "Broadbalk experiment fertilizer and manure treatments, 1852-2021", Electronic Rothamsted Archive, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
    DOI: 10.23637/rbk1-FertTreats
  • Rothamsted_Research(2018) "Broadbalk experiment plan revised 2018", Electronic Rothamsted Archive, Rothamsted Research, Harpenden, Herts, UK.
    DOI: 10.23637/rbk1-today2018-01

2016

  • 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 - Academic Press), Vol 55, Chapter 1, pp. 3-42
    DOI: 10.1016/bs.aecr.2016.08.002

2012

  • Powlson, D. S. , Bhogal, A. , Chambers, B. J. , Coleman, K. , Macdonald, A. J. , Goulding, K. W. T. and Whitmore, A. P.(2012) "The potential to increase soil carbon stocks through reduced tillage or organic material additions in England and Wales: A case study.", Agriculture, Ecosystems and Environment, 146, 23-33
    DOI: 10.1016/j.agee.2011.10.004

2009

  • Johnston, A. E. , Poulton, P. R. and Coleman, K.(2009) "Soil organic matter: its importance in sustainable agriculture and carbon dioxide fluxes", Advances in Agronomy, 101, 1-57
    DOI: 10.1016/s0065-2113(08)00801-8
  • Rothamsted_Research(2009) "Broadbalk experiment plan 1996-2017", Electronic Rothamsted Archive, Rothamsted Research, Harpenden, Herts, AL5 2JQ UK
    DOI: 10.23637/rbk1-plan1996-2017-01

2006

1996

  • Poulton, P. R.(1996) "Broadbalk Wheat Experiment", Global Change and Terrestrial Ecosystems, Report No. 7, GCTE Task 3.3.1, Soil Organic Matter Network (SOMNET): 1996 Model and Experimental Metadata (Smith P. , Smith J.U. and Powlson D.S. (eds) - GCTE Focus 3 Office, Wallingford, UK), 69-72

1993

  • Hart, P. B. S. , Powlson, D. S. , Poulton, P. R. , Johnston, A. E. and Jenkinson, D. S.(1993) "The availability of the nitrogen in the crop residues of winter wheat to subsequent crops", Journal of Agricultural Science, 121, 355-362
    DOI: 10.1017/S0021859600085555

1990

  • Jenkinson, D. S.(1990) "The turnover of organic carbon and nitrogen in soil", Philosophical Transactions of the Royal Society of London, Series B, 329, 361-368
    DOI: 10.1098/rstb.1990.0177

1983

  • Dyke, G. V. , George, B. J. , Johnston, A. E. , Poulton, P. R. and Todd, A. D.(1983) "The Broadbalk wheat experiment 1968-78: yields and plant nutrients in crops grown continuously and in rotation", Rothamsted Experimental Station Report for 1982, Part 2
    Get from eRAdoc: ResReport1982p2-5-44

1969

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