The Hoosfield spring barley experiment was started by Lawes and Gilbert in 1852. Spring barley has been grown continuously since then. The experiment offers interesting contrasts to Broadbalk; because it is spring sown it has only been necessary to fallow it four times to control weeds and it tests not only nitrogen, minerals and FYM but also sodium silicate.
The aim was to test the effects of different inorganic fertilizers (supplying the elements N, P, K Mg and sodium silicate) and farmyard manure (FYM) on the yield of spring barley. The experiment has had 4 main phases:
1. 1852-1967. Four combinations of nutrients were tested in a factorial design (strips 1-4; see plan): 0 v P v KMgNa v PKMgNa. This series was crossed by four series testing either no N or three forms of N usually applied at 48kgNha-1 (Series O, no N; Series A, ammonium sulphate; Series AA, sodium nitrate; Series C, rape cake, later castor meal). Four additional plots in the south side test: unmanured (plot 61); ashes, 1852-1932 (plot 62); residues of FYM applied 1852-1871 (plot 71); FYM since 1852 (plot 72).
The sodium nitrate series was divided in 1862 for a test of with and without sodium silicate, to see what effect this had on straw strength, which was used in large quantities in the local hat factories at that time.
The variety Plumage Archer was grown from 1917-1966. In 1927 and 1928-32 alternate strips of Plumage Archer and Spratt Archer were grown for comparison. The Spratt Archer data is shown in dataset HOOSYIELD as SA.
In 1964-1966, the plots were split in half, to compare the old variety, Plumage Archer, with the modern variety, Maris Badger (shown as plot name MB in dataset HOOSYIELD2). The amount of N applied to Maris Badger was increased to 96kgNha-1. Plumage Archer continued to receive 48kgNha-1 and the other fertilizer and manure treatments were unchanged.
There is no data for 1967, as the whole experiment was fallowed to control weeds.
2. 1968-1978. In 1968, short-strawed cultivars were introduced and a three course rotation with potatoes and beans was started on part of the experiment (series AA and C). See Hoosfield rotation 1968-1978 (pdf) for details of the cropping sequence and N fertilizer applied to the rotation each year.
Also in 1968, most of the existing plots were divided into four main plots, testing four rates of fertilizer N, replacing the test of different forms of N. See Hoosfield plan 1968-1978 (pdf). The rates are N0, N1, N2 and N3, equivalent to 0, 48, 96 and 144 kg N ha -1. The rates were fixed from 1968-1973, there was then a transition period, 1974-1980, when the N rates changed after three and four years, then since 1981 the rates of N have changed every year in the order N3-N2-N1-N0. See Hoosfield N rate sequence 1968-.xlsx for details of the sequence of N fertilizer applied since 1968.
3. 1979-2000. The three course rotation was discontinued in 1979 as the effects of a two year break were small. The testing of sodium silicates (Series AA) was modified in 1980 to test: 0 v silicate 1862-1979 v silicate since 1980 v silicate since 1862. See Hoosfield plan 1979-2000 (pdf).
4. 2001 onwards. Two new plots testing P2KMg (plot 63) and FYM (plot 73) were introduced in 2001 and Strip 5 tested various other combinations of N, P, K and Mg.
In 2003, major changes were made. On the 'Main Plots', in addition to the four-level N test, P and Mg are withheld on some plots (and on parts of Series AA) until levels of plant available P and Mg decrease to more appropriate agronomic levels. This is reviewed every year.
Response to plant-available P is tested in Series C and Strip 5; basal N is applied and some plots receive K fertiliser to ensure K is not limiting yield. On Series AA the four-level N test was stopped in 2003 and basal N applied instead to simplify the silicate test. Sodium silicate, both as fresh application and residue, continued to give substantial yield increases in the period 2002-2005 on plots lacking P or K. Hoosfield plan 2001 onwards (pdf)
For more details, refer to the Rothamsted Guide to the Classical Experiments 2006 pages 31-34 and to the Key References listed below.
The following data can be extracted using the e-RA Data Extraction Tool. Preview sets of data are also available.
Thousand grain weights (TGWs) are available from selected plots from 1974 onwards. Hectolitre weights are available from selected plots from 2005 onwards.
Grain and straw %N, P, K, Ca, Mg, Na are available for the Main plots, 1964, 1966, and 1970-2010. %S data is available from 1996 onwards.
Physical samples of crops and soils have been preserved in the Rothamsted Sample Archive. For more details please contact the e-RA Curators.
With thanks to Paul Poulton for help with compiling the text and plans.