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.
- Date Start: 1843
- Establisment Period End: 1851
- Date End: Ongoing
- Key Contacts: Andrew Gregory, (Principal Investigator), 0000-0001-7123-0784 , Sarah Perryman, (Data Manager), Margaret Glendining, (Data Manager), 0000-0002-6466-4629 ,
Description
- Started in 1843, Broadbalk is the longest running scientific experiment 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.
Funding
- The e-RA database, including the published datasets generated from it, is part of the Rothamsted Long-Term Experiments - National Bioscience Research Infrastructure (RLTE-NBRI) , which also includes the Long-Term Experiments, the 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 supported by the Lawes Agricultural Trust and the Biotechnology and Biological Sciences Research Council (Grants BBS/E/C/00005189 (2012-2017); BBS/E/C/000J0300 (2017-2022); BBS/E/RH/23NB0007 (2023-2028)).
Keywords
- arable farming, arable soils, bacterial genomes, bare fallow, botanical composition, broadbalk long-term experiment, broadbalk wilderness experiment, copper, crop rotation, crop yield, cropping system, ecological metagenomes, experimental design, farmyard manure, fertilizer, field beans, flora, functional genomics, fusarium spp, grain yield, herbicides, highfield ley-arable rotation experiment, iron, liming, long term experiments, magnesium, maize, microbial ecology, micronutrient, mineral content, nitrogen, nitrogen content, nitrogen fertilizers, oats, pathogenic fungi, phosphorous, phosphorus fertilizers, plant available phosphorus, plant footrot, plant fungal diseases, plant population, potassium, potassium fertilizers, potatoes, rothamsted research, selenium, soil, soil biology, soil bulk density, soil exchangeable calcium concentration, soil exchangeable potassium concentration, soil fertility, soil microbiome, soil microorganisms, soil organic carbon, soil ph, soil total nitrogen concentration, statistical data, statistics, straw, weeds, wheat, zinc
Datasets available
| Title (hover for a longer description) | Year of Publication | Identifier | Version |
|---|---|---|---|
Crop nutrient data | |||
| Broadbalk wheat grain micronutrients 1845-2005 | 2024 | https://doi.org/10.23637/rbk1-trace2005-01 |
01 |
| Broadbalk Crop Nutrient Content, Wheat 1968-2017 | 2021 | https://doi.org/10.23637/rbk1-BKNUTRW-01 |
01 |
Crop yield data - Annual | |||
| Broadbalk Wheat annual grain and straw yields 1852-1925 | 2021 | https://doi.org/10.23637/rbk1-1796346264-1 |
01 |
| Broadbalk Wheat annual grain and straw yields 1926-1967 | 2023 | https://doi.org/10.23637/rbk1-yld2667-01 |
01 |
| Broadbalk Wheat annual grain and straw yields 1968-2022 | 2023 | https://doi.org/10.23637/rbk1-yld6822-01 |
01 |
| Broadbalk field bean yield components 1968-2022 | 2023 | https://doi.org/10.23637/rbk1-beanyld6822-01 |
01 |
| Broadbalk forage maize yields 1997-2017 | 2023 | https://doi.org/10.23637/rbk1-fmyield9717-01 |
01 |
| Broadbalk oats grain and straw yields 1996-2022 | 2025 | https://doi.org/10.23637/rbk1-oatyld9622-01 |
01 |
| Broadbalk potato tuber yields 1968-1996 | 2025 | https://doi.org/10.23637/rbk1-potyld6896-01 |
01 |
| Fisher 1921 Broadbalk wheat grain yields 1852-1918 | 2018 | https://doi.org/10.23637/rbk1-data-fisher-1921-01 |
01 |
| Broadbalk Wheat yields and N uptake Section 1, 2001-2015 | 2022 | https://doi.org/10.23637/rbk1-yldS10115-01 |
01 |
Crop yield data - Summary | |||
| Broadbalk mean long-term yields of winter wheat 1852-2022 | 2023 | https://doi.org/10.23637/rbk1/meanWWYields1852-2022-03 |
03 |
| Broadbalk Wheat 10-year mean yields 1852-1967 | 2023 | https://doi.org/10.23637/rbk1-meanyld5267 |
01 |
Disease data | |||
| Broadbalk Wheat brown foot rot (Fusarium spp.) 1992-2009 | 2021 | https://doi.org/10.23637/rbk1-bfr-01 |
01 |
Experiment details | |||
| Broadbalk Wheat Experiment organic manure chemical composition | 2024 | https://doi.org/10.23637/rbk1-FYM-01 |
01 |
| Broadbalk Wheat Chalk Applications | 2022 | https://doi.org/10.23637/rbk1-chalk-01 |
01 |
Soil data | |||
| Broadbalk soil chemical properties 1843-2021 | 2025 | https://doi.org/10.23637/rbk1-bksoils-01 |
01 |
| Broadbalk soil organic carbon content 1843-2015 | 2021 | https://doi.org/10.23637/KeyRefOABKsoc-02 |
02 |
| Broadbalk soil metagenomic study | 2024 | rbk1/01-METAGEN - PRJEB54688 |
01 |
| Broadbalk Soil Total % Nitrogen Content, 1843-2010 | 2018 | https://doi.org/10.23637/BK-oadata-soilN-01 |
01 |
| Broadbalk changes in Olsen P in top soil, 1843-2010 | 2016 | https://doi.org/10.23637/keyrefoabkolsenp |
01 |
Species observation data | |||
| Cirsium arvense frequency on Broadbalk Section 8 1991-2018 | 2019 | https://doi.org/10.23637/bbk-2078416917-01 |
01 |
| Broadbalk Weed Survey Data 1991-2021 | 2023 | https://doi.org/10.23637/rbk1-weeds_1991-2021_01 |
01 |
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Key Information
Leaflet describing Broadbalk
Short handout describing the experiment and it's history
Plans and Treatments
Experimental plans, fertilizer treatments, chalk, cropping details, and dates of key field operations, 1852-present
Broadbalk Dataset for School
Scholastic Dataset
Crop nutrient content
Information about analytical methods for crop macro nutrient content (% N, P, K, Ca, Mg, Na and S)
Disease surveys
Information about the wheat root and stem diseases assessed (take-all, eyespot, sharp eyespot and brown foot rot)
Earthworms
Information about earthworm measurements on Broadbalk
Grain quality assessment
Description of what grain quality data is available (TGWs, Hagberg falling number ,Hectolitre weights, grain size categories), and analytical methods used
Other crops and fallow
Description of potatoes, oats, beans and forage maize crops grown on Broadbalk, and the management of the fallow
Soil chemical properties
Details of which soil chemical properties have been measured, analytical methods used and soil sampling methods
Soil physical properties and site details
Site details, plot area, soil moisture and drainage, soil description and texture and soil weights
Weeds surveys
Information about the weed surveys on Section 8 (no herbicides), 1991-present, and earlier surveys on the whole experiment, 1933-1979.
Wheat yield background information
Description of harvest methods and datasets available
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 Andrew Gregory
- 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 | 10mg/kg (milligram per kilogram) | 1843 | YES | NO |
| Soil density | 1.25g/cm3 (gram per cubic centimetre) | 1843 | YES | NO |
| Soil organic carbon | 28.8t/ha (tonnes per hectare) | YES | NO |
Experiment Design
Use the arrows to navigate between periods
- 1 - Early period - 1852 - 1925 - 
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
- Experiment Design Type: Demonstration strip design
- Number of Plots: 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.
| Level Name | Factor Name | Amount | Years | Frequency | Method | Chemical Form | Notes |
|---|---|---|---|---|---|---|---|
| N1 | Nitrogen Fertilizer Exposure | 48 kgN/ha | 1852 - 1925 | 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* | Nitrogen Fertilizer Exposure | 48 kgN/ha | 1852 - 1925 | Broadcast Application Method | Sodium Nitrate | All applied in spring, as one application until 1898, as two equal amounts 1899-1925 | |
| N1. 5 | Nitrogen Fertilizer Exposure | 72 kgN/ha | 1852 - 1878 | Broadcast Application Method | Ammonium Sulfate | Applied to Plot 19 with rape cake, All applied in autumn | |
| N2 | Nitrogen Fertilizer Exposure | 96 kgN/ha | 1852 - 1925 | 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* | Nitrogen Fertilizer Exposure | 96 kgN/ha | 1852 - 1925 | Broadcast Application Method | Sodium Nitrate | All applied in spring, as one application until 1898, as two equal amounts 1899-1925 | |
| N3 | Nitrogen Fertilizer Exposure | 144 kgN/ha | 1852 - 1925 | 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 | Nitrogen Fertilizer Exposure | 192 kgN/ha | 1852 - 1864 | Annually | Broadcast Application Method | Ammonium Sulfate | All applied in autumn |
| Farmyard Manure | Farmyard Manure Exposure | 35 t/ha | 1843 - 1925 | Annual | 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 | ||
| P | Phosphate Fertilizer Exposure | 35 kg/ha | 1843 - 1925 | Annually | Chemical Basal Application | Triple Superphosphate | Applied in the autumn, omitted 1915 |
| K | Potassium Fertilizer Exposure | 90 kg/ha | 1843 - 1925 | Annually | Fertilizer Basal Application | Potassium Sulphate | Applied in the autumn, omitted 1915, 1917-1919 |
| Na | Sodium Nutrient Exposure | 16 kg/ha | 1843 - 1925 | Annually | Fertilizer Basal Application | Sodium Sulphate | Applied in the autumn, omitted 1915 |
| Mg | Magnesium Nutrient Exposure | 11 kg/ha | 1843 - 1925 | Annually | Fertilizer Basal Application | Magnesium Sulfate | Applied in the autumn, omitted 1915 |
| C | Rapeseed Cake Exposure | 96 kgN/ha | 1852 - 1926 | Annually | 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 |
|---|---|---|---|---|
| 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. |
| Weight per Bushel Dressed Corn | lb | Annually | SpecifiedCrop | Bushel weights can be used to derive Hectolitre weights (HLWT),a measure of grain quality. |
| 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. |
- 
- 2 - Middle period - 1926 - 1967 -
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
- Experiment Design Type: Demonstration strip design
- Number of Plots: 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.
| Level Name | Factor Name | Amount | Years | Frequency | Method | Chemical Form | Notes |
|---|---|---|---|---|---|---|---|
| N1 | Nitrogen Fertilizer Exposure | 48 kg/ha | 1926 - 1967 | Twice | Broadcast Application Method | Ammonium Sulfate | 24kgN applied in autumn, remainder in spring |
| N2 | Nitrogen Fertilizer Exposure | 96 kg/ha | 1926 - 1967 | Twice | Broadcast Application Method | Ammonium Sulfate | 24kgN applied in autumn, remainder in spring |
| N3 | Nitrogen Fertilizer Exposure | 144 kg/ha | 1926 - 1967 | Twice | Broadcast Application Method | Ammonium Sulfate | 24kgN applied in autumn, remainder in spring |
| N1* | Nitrogen Fertilizer Exposure | 48 kg/ha | 1926 - 1967 | Twice | Broadcast Application Method | Sodium Nitrate | Applied in spring as two equal amounts |
| N2* | Nitrogen Fertilizer Exposure | 96 kg/ha | 1926 - 1967 | Twice | Broadcast Application Method | Sodium Nitrate | Applied in spring as two equal amounts |
| Farmyard Manure | Farmyard Manure Exposure | 35 t/ha | 1926 - 1967 | Once a Year | 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 |
|---|---|---|---|---|
| Yield Components | t/ha | Annually | SpecifiedCrop | Grain and straw yields at field moisture content, approximately 85% dry matter. |
| Weight per Bushel Dressed Corn | lb | Annually | SpecifiedCrop | Bushel weights can be used to derive hectolitre weights (HLWT), a measure of grain quality |
| 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) |
- - 3 - Current period - 1968 - Now
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 Wheat | 1968 - |
| Oats | 1996 - |
| Spring Beans | 1968 - 1978 |
| Potatoes | 1968 - 1996 |
| Winter Beans | 2018 - |
| Fallow | |
| Maize | 1997 - 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.
| Level Name | Factor Name | Amount | Years | Frequency | Method | Chemical Form | Notes |
|---|---|---|---|---|---|---|---|
| N1 | Nitrogen Fertilizer Exposure | 48 kgN/ha | 1968 - | Annually in Mid-april | Ammonium Nitrate | ||
| N2 | Nitrogen Fertilizer Exposure | 96 kgN/ha | 1968 - | Annually in Mid-april | Ammonium Nitrate | ||
| N3 | Nitrogen Fertilizer Exposure | 144 kgN/ha | 1968 - | Annually in Mid-april | Ammonium Nitrate | ||
| N4 | Nitrogen Fertilizer Exposure | 192 kgN/ha | 1968 - | Annually in Mid-april | Ammonium Nitrate | ||
| N5 | Nitrogen Fertilizer Exposure | 240 kgN/ha | 1985 - | Annually in Mid-april | Ammonium Nitrate | ||
| N6 | Nitrogen Fertilizer Exposure | 288 kgN/ha | 1985 - | Annually in Mid-april | Ammonium Nitrate | ||
| N1+1+1 | Nitrogen Fertilizer Exposure | 144 kgN/ha | 2001 - | Mid-march, Mid-april, Mid-may | Ammonium Nitrate | N2+1 for maize 1997-2017 | |
| N1+2+1 | Nitrogen Fertilizer Exposure | 192 kgN/ha | 2001 - | Mid-march, Mid-april, Mid-may | Ammonium Nitrate | N2+2 for maize 1997-2017 | |
| N1+3+1 | Nitrogen Fertilizer Exposure | 240 kgN/ha | 2001 - | Mid-march, Mid-april, Mid-may | Ammonium Nitrate | N2+3 for maize 1997-2017 | |
| N1+4+1 | Nitrogen Fertilizer Exposure | 288 kgN/ha | 2001 - | Mid-march, Mid-april, Mid-may | Ammonium Nitrate | N2+4 for maize | |
| K | Potassium Fertilizer Exposure | 90 kgK/ha | 1968 - | Annually in Autumn | Potassium Sulphate | ||
| K2 | Potassium Fertilizer Exposure | 180 kgK/ha | 2001 - 2005 | Annually in Autumn | Potassium Sulphate | ||
| K* | Potassium Fertilizer Exposure | 90 kgK/ha | 2001 - | Annually in Autumn | Potassium Chloride | ||
| P | Phosphate Fertilizer Exposure | 35 kgP/ha | 1968 - | Annually in Autumn | Calcium Bis(dihydrogenphosphate) | ||
| Na1 | Sodium Nutrient Exposure | 16 kgNa/ha | 1968 - 1973 | Annually in Autumn | Sodium Sulphate | ||
| Na2 | Sodium Nutrient Exposure | 55 kgNa/ha | 1968 - 2000 | Annually in Autumn | Sodium Sulphate | 57 kgNa/ha until 1973 | |
| Mg | Magnesium Nutrient Exposure | 12 kgMg/ha | 1968 - | Annually in Autumn | Magnesium Sulfate | 11kgMg until 1973. 35 kgMg every 3rd year 1974-2000. | |
| Mg2 | Magnesium Nutrient Exposure | 24 kgMg/ha | 2001 - 2005 | Annually in Autumn | Magnesium Sulfate | Plus 60 kg Mg in autumn 2000 only | |
| Mg* | Magnesium Nutrient Exposure | 30 kgMg/ha | 1968 - 2000 | Annually in Autumn | Magnesium Sulfate | 31kgMg as magnesium sulphate until 1973 | |
| Fym | Farmyard Manure Exposure | 35 t/ha | 1968 - | Annually in Autumn | Farmyard Manure | Derived from cattle. Not applied to beans from 2018, not applied to oats 1996-2017. | |
| Residual Fym | Farmyard Manure Exposure | 2001 - | Plots previously receiving FYM | ||||
| C | Castor Meal Exposure | 96 kgN/ha | 1968 - 1988 | Annually |
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 |
|---|---|---|---|---|
| Yield Components | t/ha | Annually | AllCrops | Grain and straw at 85% dry matter. |
| Hectolitre Grain Weight | Annually | SpecifiedCrop | Since 1999 selected plots only | |
| Thousand Grain Weight | Annually | SpecifiedCrop | Since 1974 selected plots only | |
| 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. | |
| Harvest Date | Annually | AllCrops | Sowing and harvest dates of all crops | |
| Earthworm Abundance | Occasional | Selected plots, occasional years. |
License
These media (images and videos) are
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Attribution Licence (4.0) with attribution to Rothamsted Research.
Videos
Video on the Broadbalk Experiment
A visually engaging short film on the Broadbalk experiment.
Images
Key References
2024
- - Poulton, P. R., Johnston, A. E., Glendining, M. J., White, R. P., Gregory, A. S., Clark, S. J., Wilmer, W. S., Macdonald, A. J. and Powlson, D. S. (2024) "The Broadbalk Wheat Experiment, Rothamsted, UK: Crop yields and soil changes during the last 50 years", Advances in Agronomy DOI: https://doi.org/10.1016/bs.agron.2023.11.003
2021
- - 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: https://doi.org/10.1098/rsif.2021.0250
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: https://doi.org/10.1016/j.agrformet.2019.107898
- - Macholdt, J., Piepho, H.-P., Honermeier, B., Perryman, S., Macdonald, A. and Poulton, P. R. (2020) "The effects of cropping sequence, fertilization and straw management on the yield stability of winter wheat (1986–2017) in the Broadbalk Wheat Experiment, Rothamsted, UK", The Journal of Agricultural Science, 158, 65–79 DOI: https://doi.org/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: https://doi.org/10.1111/ejss.12521
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: https://doi.org/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 & Environment, 146, 23–33 DOI: https://doi.org/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: https://doi.org/10.1016/s0065-2113(08)00801-8
2006
- - Rothamsted_Research (2006) "Guide to the Classical and other Long-term Experiments, Datasets and Sample Archive (reprinted 2012)", Rothamsted Research, Lawes Agricultural Trust Ltd, Harpenden UK , , DOI: https://doi.org/10.23637/rothamsted-long-term-experiments-guide-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", The Journal of Agricultural Science, 121, 355–362 DOI: https://doi.org/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: https://doi.org/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 , 5–44 Get from eRAdoc: ResReport1982p2-5-44
1969
- - Avery, B. W. and Bullock, P. (1969) "The soils of Broadbalk: Morphology and classification of Broadbalk soils", Rothamsted Experimental Station Report for 1968 , , 63–81 with references pp 112–115 Get from eRAdoc: ResReport1968p2-63-81
- - Garner, H. V. and Dyke, G. V. (1969) "The Broadbalk Yields", Rothamsted Experimental Station Report for 1968 , Part 2 , 26–46; with references pp 49 Get from eRAdoc: ResReport1968p2-26-46
- - Johnson, C. G., Lofty, J. R. and Cross, D. J. (1969) "Insect pests on Broadbalk", Rothamsted Experimental Station Report for 1968 , Part 2 , 141–156 Get from eRAdoc: ResReport1968p2-145-160
- - Johnston, A. E. (1969) "The plant nutrients in crops grown on Broadbalk", Rothamsted Experimental Station Report for 1968 , Part 2 , 50–62 Get from eRAdoc: ResReport1968p2-50-62
- - Johnston, A. E. (1969) "The soils of Broadbalk: Plant nutrients in Broadbalk soils", Rothamsted Experimental Station Report for 1968 , Part 2 , 93–115 Get from eRAdoc: ResReport1968p2-93-115
- - Johnston, A. E. and Garner, H. V. (1969) "Broadbalk: Historical Introduction", Rothamsted Experimental Station Report for 1968 , Part 2 , 12–25 Get from eRAdoc: ResReport1968p2-12-25
