Alternate Wheat and Fallow
- Local identifier
- R/WF/3
- Years operational
- 1856—2014
- Description
- The Alternate Wheat and Fallow experiment was started by Lawes and Gilbert in 1856, on a 0.4 ha site on part of Hoosfield. The experiment originally had two strips which alternated winter wheat and a bare fallow in successive years. Between 1932 and 1982, a modification was introduced to allow a yearly comparison of a one-year and a three-year fallow but the effects on the yield of the subsequent wheat crop were small and since 1983 the experiment has reverted to the original design. The wheat cultivar grown has usually been the same as on Broadbalk, and the effects of fallowing on the yield of winter wheat can be roughly estimated by comparing yields from this experiment with continuous, unmanured wheat on Broadbalk (plot 03). In the first 10 years of the experiment the one-year fallow gave an extra 0.6 t ha-1, but over the next 60 years the difference was even smaller (0.14 t ha-1). Since its reversion to the original design in 1983, and with modern cultivars, average yields of the wheat after a one-year fallow have been 1.7 t ha-1. When expressed on the basis of the whole area (i.e. wheat plus fallow), the yield of 0.85 t ha-1 is slightly less than the 1.0 t ha-1 for continuous wheat on Broadbalk. Since autumn 2015, the whole experiment (both plots) has been sown to winter wheat, the same variety as is grown on Broadbalk. A small amount of N fertilizer (50 kg N ha-1) is applied in spring (mid-April), but to maintain the low soil P and K status, no other fertilizers are applied. No yields or crop samples have been taken since harvest 2015. It was in this experiment in 1935, that symptoms caused by the fungal pathogen Gibellina cerealis or 'white straw disease' were first recorded in the UK.
- Data Access Statement
- Available to any researcher on request
- Data license
- CC BY
- Data URL
- http://www.era.rothamsted.ac.uk/Alternate
- Data policy
- Yes (not online)
- Organization
- Rothamsted Researchresearch organisation
- People
- Dr Andy Macdonaldprincipal investigatorRothamsted ResearchSustainable Agricultural SystemsDr Sarah Perrymandata managerRothamsted ResearchComputational and Analytical Sciences
Site: Hoosfield
- Type
- research station field
- Location
- HarpendenHertfordshireUnited Kingdom
- Geographic location
- 51.812632, -0.375997
- Elevation
- 131 Metres
- Visits permitted?
- Yes
- Visiting arrangements
- By arrangement with Dr Andy Macdonald
- History
- The experiment is sited on part of Hoosfield that had received no applications of fertilizers or manures since 1851.
- Soil type
- luvisol
Design period: Original Scheme (1856—1931)
- Design description
- Two half acre strips, A and B, lie side by side, one carrying wheat while the other is fallow. These treatments alternate each year. No fertilisers are applied.
- Number of plots
- 2
- Number of harvests per year
- 1
- Crops
Crop Years grown wheat fallow - Measurements
Variable Material Units Frequency Scale Comment harvested surface area wheat ha annually plot grain yield trait wheat t/ha annually plot At field moisture content harvest date Not specified date annually plot Start and end date forage yield wheat t/ha annually plot straw yield
Design period: Revised Scheme (1932—1982)
- Description
- A modification was made to enable the effect of a 1 year fallow to be compared with that of a 3 year fallow.
- Design description
- Each original A and B strip was divided transversly into 4 equal sections. When a strip carries wheat, only 3 of the 4 sections are cropped, the fourth section being left fallow. Each of the eight sections has a triple fallow in turn with an eight year cycle having 5 fallow and 3 cropped years Between the autumn of 1956 and 1960 each strip was divided in half longitudinally. The centre two halves continued the eight year cycle while the outer plots were assigned to the Entomology department for studies wheat bulb fly. No fertilizers were used. Between 1963 and 1966 plots were split to compare varieties Squarehead's Master 13/4 (Kloka 1966), Capelle and Rothwell Perdix.
- Number of plots
- 8
- Number of harvests per year
- 1
- Crops
Crop Years grown wheat fallow - Crop Rotation
- WFFFWFWF
- 1wheat
- 2fallow
- 3fallow
- 4fallow
- 5wheat
- 6fallow
- 7wheat
- 8fallow
- Measurements
Variable Material Units Frequency Scale Comment harvested surface area Not specified ha annually plot harvest date Not specified date annually plot start and end date grain yield trait wheat t/ha annually plot Measured at field moisture content until 1957 and 85% dry matter from 1958 forage yield wheat t/ha annually plot Measured at field moisture content until 1957 and 85% dry matter from 1958 fallow years Not specified The number of consecutive fallow years
Design period: Reversion to Original Scheme (1983—2015)
- Design description
- The four sections for each strip were merged reverting the experiment to the original two strip design.
- Number of plots
- 2
- Number of harvests per year
- 1
- Crops
Crop Years grown wheat fallow - Measurements
Variable Material Units Frequency Scale Comment harvest date wheat date annually plot harvested surface area Not specified ha annually plot grain yield trait wheat t/ha annually plot Measured at 85% dry matter forage yield wheat t/ha annually plot Measured at 85% dry matter
Design period: Low P and K Maintenance (2016—)
- Description
- Since autumn 2015, the whole experiment (both plots) has been sown to winter wheat, the same variety as is grown on Broadbalk. A small amount of N fertilizer (50 kg N ha-1) is applied in spring (mid-April), but to maintain the low soil P and K status, no other fertilizers are applied. No yields or crop samples have been taken since harvest 2015.
- Number of plots
- 1
- Number of harvests per year
- 1
- Crop
Crop Years grown wheat