DOI: 10.23637/rbk1-beanyld6822-01
title: Dataset: Broadbalk field bean yield components 1968-2022

description: Annual field bean (*Vicia faba*) yields for each treatment plot of the Broadbalk Experiment, with details of all fertilizer and manure applications. Also thousand grain weights (TGWs) and other agronomic information, including sowing and harvest dates, and bean cultivars. Field beans were grown as part of the arable rotation on Broadbalk in 1968-1978 (spring beans, Sections 2, 4 and 7) and 2018-2022 (winter beans, Sections 2-5 and 7).
description: The [Broadbalk Wheat Experiment](experiment/rbk1) was started in autumn 1843 to investigate the effects of fertilizers containing N, P, K, Na and Mg in various combinations, and organic manure, on the yield of winter wheat grown continuously. The treatment STRIPS extend the whole length of the field; each strip tests a different fertilizer or manure treatment. In 1926 the strips were divided into five SECTIONS (I-V), bare fallowed in sequence to control weeds. There were further divisions in 1955 making seven Sections (IA-VB). Each PLOT is a unique strip\section combination. In 1968 the experiment was divided into ten SECTIONS (0-9), to allow the comparison of wheat grown continuously with wheat in a three or five-year rotation. Wheat is grown in rotation with other arable crops (beans, potatoes, oats or forage maize) and fallow in Sections 2-5 and 7. Wheat only is grown in the other sections. Strip 1 was added in 1968, on Sections 2-7 only. 

See Section_names.pdf which shows changes in the Broadbalk sections over time.
description: An Excel file, 01-BKbeans6822.xlsx, contains the Broadbalk bean grain yield components and treatment details, for 1968-2022. Frictionless CSV files are provided for users who prefer CSV over Excel files. A README file contains extensive metadata information.
Section_names.pdf which shows the changes in the Broadbalk sections over time.
description: Bean grain and bean straw yields are at 85% dry matter. Bean straw is that part of the bean stalks and leaves cut by the combine harvester, and does not include the stubble and broken pieces of leaf or stem which fall to the ground. Bean straw is removed at harvest. 

Spring beans grown 1968-1978 received N, FYM and other fertilizers at the same rate as the winter wheat. Winter beans grown from 2018 onwards did not receive N or FYM, but received P, K and Mg at the same rate as the winter wheat. 

TGWs calculated from two sub-samples of 100 bean grains, is the weight in grams of 1000 beans, expressed at 100% dry matter. 

Current strip 21 is also known as 2.1, 2a and 2A; current strip 22 is also known as 2.2, 2b and 2B. By convention, the year is that of harvest (not sowing). 

Yields from wheat and the other non-wheat crops are published separately. See section_names.pdf for full details of layout and the cropping plans for details of the different crop rotations.
description: Yields of grain and straw and TGWs are from the BKBEANS datasets in the e-RA database (e-RAdata). Treatment details were taken from the Rothamsted Yield Books, published each year with details of each experiment. In accordance with the Joint Code of Practice for Research at Rothamsted, data processing in e-RA follow rigorous standard operating procedures to ensure the quality and correctness of data collected in the field through to depositing in the e-RA database. To ensure quality control during data inputting, the data sets were typed on two separate occasions (double data entry). During the second typing (verification) the data values were compared with those typed on the earlier occasion, and any discrepancies were resolved before verification continued. This procedure also set out how to handle situations where the written records were illegible or ambiguous. This procedure avoided visual checking of data, which can be very inaccurate. Once the data were entered into e-RA, they were independently back-checked against the original data sheets. We thank the many other [Rothamsted staff](info/credits) who have been involved in the production of this data, including farm staff, field recorders, laboratory staff and data recorders, too numerous to mention.