nzhang_raw_data.txt

soil samples were taken from Plot 3 and Plot 14/2 from the Park Grass Experiment at Rothamsted Experimental Station, dating back to 1870, 1876, 1906, 1923, 1959, 1976, 1984, 1991, 1998, 2002, 2005 and 2008 for the plot 3 and 1870, 1876, 1906, 1923, 1939, 1959, 1984, 1991, 1998, 2002, 2005 and 2008 for the plot 14/2. Plot 3 had not received fertilizer since 1856 (control). Plot 14/2 was fertilized with 96kg N ha-1 y-1 as sodium nitrate in spring since 1856 with additional minerals (35 kg P ha-1 y-1 as triple superphosphate, 225 kg K ha-1 y-1 as potassium sulfate, 15 kg Na ha-1 y-1 as sodium sulfate, and 10 kg Mg ha-1 y-1 as magnesium sulfate, and no lime was applied. Totally, there are 24 archived soil samples, 12 control samples and 12 fertilized samples.