DOI: 10.23637/rbk1-fym-01
title: Dataset: Broadbalk Wheat Experiment organic manure chemical composition

description: Details of the chemical composition of the organic manures applied to the Broadbalk Wheat Experiment, 1850-2019. Farmyard manure (FYM) is applied each autumn at 35t/ha to treatment strip 2.1 (also known as 2A or 21) since 1885, to treatment strip 2.2 (also known as 2B or 22) since 1843, and to strip 01 in 1968-2000 only, from cattle housed on cereal straw. Rapeseed cake or castor bean meal was applied to strip 19 until 1988, to supply around 96kgN/ha; it was also applied to other strips 1843-1872. FYM and castor bean meal has been analysed routinely since 1967. This dataset gives details of the chemical composition: % total N, C, P, K, Ca, Mg, Na and S, and the total amount of each element applied each year 1967-2019. There is also some limited mean data for earlier periods and trace element data for 1982 and 1983. 


The FYM supplies on average 249 kgN/ha, 48 kgP/ha and 326kgK/ha; the rape cake/castor meal 104 kgN/ha, 17 kgP/ha and 19 kgK/ha. For comparison, the standard inorganic fertilizer treatments on Broadbalk receive 0-288 kgN/ha, 35kgP/ha, and 90 kgK/ha.
description: Total concentration of nitrogen determined in fresh sample (not dried) at normal (ambient) moisture content by Kjeldahl digestion. Total carbon determined by combustion in oven-dry samples. Total P, K, Ca, Mg, Na, S and trace elements determined in oven-dry samples by digestion with 6M HCl, the extracts analysed by ICP-OES.
description: An Excel file with annual data, 1967-2019 and some earlier data. Frictionless CSV files are also provided for users who prefer the CSV format.
description: Rapeseed cake was applied to strip 19 1852-1940, and replaced by castor bean meal, 1941-1988. Rapeseed cake was also applied to several other strips, 1843-1872.

Two samples, A and B, were taken of the FYM applied each year, from the front and back of the trailer containing the FYM. 

Trace elements (Fe, Mn, Zn, Cu, Ni, Co, Cd, Cr and Pb) were measured on samples applied for the 1982 and 1983 harvest years. Two replicate samples (1 and 2) were taken from each sample for analysis. If the value was below the Limit of Detection of the equipment used, it is shown as LOD, and the actual LOD is listed in the fields_metadata under the appropriate trace element.
description: Early mean data from Warren, R.G. and Johnston, A.E. (1962), Rothamsted Report for 1961, Table 9. Additional data from the Broadbalk White Books, and the Rothamsted Library Archive. The majority of the data was compiled from sample analysis data sheets. 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. Data checked by Paul Poulton and Andy Gregory. 

The Analytical Chemistry Unit follows the Joint Code of Practice (JCoPR) and participates in European Quality Assurance programmes. All performance is strictly monitored using certified external standards alongside in-house standard materials. Standards and check samples are monitored and recorded.