Alternate Wheat and Fallow

  • Experiment Code: R/WF/3
  • Experiment Site: Rothamsted
  • 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.
  • Date Start: 1856
  • Date End: 2014

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

Funding

Experimental 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.

Design

  • Period: 1856 - 1931
  • Number of Blocks: 2
  • Number of Harvests per Year: 1

Crops

Crop Years Grown
Wheat
Fallow

Measurements

Variable Unit Collection
Frequency
Material Description Crop
Harvested Surface Area ha annually SpecifiedCrop wheat
Grain Yield Trait t/ha annually SpecifiedCrop At field moisture content wheat
Harvest Date date annually Start and end date
Forage Yield t/ha annually SpecifiedCrop straw yield wheat

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.

Design

  • Period: 1932 - 1982
  • Number of Blocks: 8
  • Number of Harvests per Year: 1

Crops

Crop Years Grown
Wheat
Fallow

Crop Rotations

Rotation Crops
WFFFWFWF ( - ) Wheat > Fallow > Fallow > Fallow > Wheat > Fallow > Wheat > Fallow

Measurements

Variable Unit Collection
Frequency
Material Description Crop
Harvested Surface Area ha annually
Harvest Date date annually start and end date
Grain Yield Trait t/ha annually SpecifiedCrop Measured at field moisture content until 1957 and 85% dry matter from 1958 wheat
Forage Yield t/ha annually SpecifiedCrop Measured at field moisture content until 1957 and 85% dry matter from 1958 wheat
Fallow Years The number of consecutive fallow years

Description

  • The four sections for each strip were merged reverting the experiment to the original two strip design.

Design

  • Period: 1983 - 2015
  • Number of Blocks: 2
  • Number of Harvests per Year: 1

Crops

Crop Years Grown
Wheat
Fallow

Measurements

Variable Unit Collection
Frequency
Material Description Crop
Harvest Date date annually SpecifiedCrop wheat
Harvested Surface Area ha annually
Grain Yield Trait t/ha annually SpecifiedCrop Measured at 85% dry matter wheat
Forage Yield t/ha annually SpecifiedCrop Measured at 85% dry matter wheat

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.

Design

  • Period: 2016 - Now
  • Number of Blocks: 1
  • Number of Harvests per Year: 1

Crops

Crop Years Grown
Wheat

Site: Hoosfield - Rothamsted

  • Experiment Site: Rothamsted
  • Description: The experiment is sited on part of Hoosfield that had received no applications of fertilizers or manures since 1851.
  • Visit Permitted?: Yes
  • Visiting Arrangments: By arrangement with Dr Andy Macdonald
  • Elevation: 131 Metres
  • Geolocation:    51.812632, -0.375997

Soil

  • Type: Luvisol
Datasets for Alternate Wheat and Fallow are only available through e-RAdata. Please register for access.

Key References

1991

1985

  • Glynne, M. D. , Fitt, B. D. L. and Hornby, D. (1985) "Gibellina cerealis, an unusual pathogen of wheat", Transactions of the British Mycological Society, 84, 653-659

1957

1936

  • Glynne, M. D. (1936) "Some new British records of fungi on wheat, Cercosporella herpotrichoides Fron. Gibellina cerealis Pass. and Ophiobolus herpotrichus (Fr.) Sacc.", Transactions of the British Mycological Society, 20, 120-122

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