DOI: 10.23637/rrn1-hlacrop4923-01
title: Dataset: Highfield Ley-arable Experiment cropping sequence 1949-2023

description: Cropping details of the Highfield Ley-arable experiment, 1949-2023, with details of the arable and ley-arable rotation sequences in each of the twelve blocks, and the different treatment crops and varieties. The experiment was designed to test the effects of different rotations with and without leys (short-term herbage) on the yield of three arable test crops, in a site that had been in long-term grassland. Additionally, plots of old grassland from before the experiment started were left for comparison with the ley treatments, and other plots were ploughed and reseeded with grass at the start of the experiment. This is a companion to the Fosters ley arable experiment, started at the same time on a site that had been in long-term arable. It is now an important resource for investigating long-term changes in soil organic matter due to different cropping systems.

This dataset was assembled by Fergus Blyth from September 2022 to August 2023 as part of a year spent on placement for an MSci degree from the University of Glasgow.

This work was supported by the Natural Environment Research Council [NE/S007423/1], through the ENVISION Doctoral Training Partnership, Research Experience Placement scheme.
description: The main data table consists of the treatment rotations followed and crops grown in each plot and block each year. It contains the rotations, the crop codes (crop types) and crop varieties. Originally it consisted of 144 main plots, divided over 12 blocks. From 1968, blocks 5-12 were turned over to continuous wheat cropping to study the effects of take-all disease and are not included further in this dataset, except the 1st, 2nd and 3rd test crops in blocks 6, 7, 10 and 11, which continued until 1971. Blocks 1-4 are maintained to this day, although the measuring of yields was halted in 1990. 

The experiment began with a cut-grass (Cg) treatment, a grazed ley (L) treatment, a lucerne treatment (Lu) and an arable with hay treatment (A), as well as the permanent old grass (G) and the reseeded grass (R). The crops and treatments used in the A treatment changed several times over the course of the experiment. The L and Cg treatments were discontinued in 1962 in favour of a clover-grass (Lc) and an all-grass (Ln) treatment, respectively. Some R plots were ploughed up and converted to the arable with hay treatment in the late 1960s, before being returned to reseeded grass in the 1970s (Rp). The G, R and Rp treatments were divided into two subplots (1 and 2) from 1962-1990 to test grass with nitrogen (n) and grass/clover (c). From 1991 the G, and R and Rp plots were no longer split and were all under grass/clover, called Gc, Rc or Rpc. The Lu and Ln plots were converted to Lc plots in 1991. Several changes were made in 2009: the Lc plots that had previously been Lu were turned over to arable treatment (Al), and the Lc plots that had previously been Ln were turned over to permanent fallow (F). The Rc and Rpc plots and pre-existing A plots were turned over to the Highfield Conversion Experiment (R/CS/767).
description: - Cropping data, with details of the crop grown on each plot each year.
- Crop types, including variety. 
- Rotation types, with details of the different arable and ley-arable rotations.
description: The main plots are in pairs. At conception in 1949, it consisted of 144 main plots, divided over 12 blocks. It now numbers 48 plots, divided over 4 blocks. The year refers to harvest year; the experiment was started in autumn 1948 with the first crop harvested in 1949.
description: Taken from the Rothamsted Yield Books, field plans and paper archive. The frictionless dataset of crop sequence data was compiled by Fergus Blyth and checked by Margaret Glendining and Sarah Perryman, July 2023.