10.1371/journal.pone.0174632.g005 Jonathan Kidd Jonathan Kidd Peter Manning Peter Manning Janet Simkin Janet Simkin Simon Peacock Simon Peacock Elizabeth Stockdale Elizabeth Stockdale Changes in mean hay yield at Palace Leas for the FYM (20 t ha<sup>-1</sup>) and four ammonium sulphate-containing fertilizer treatments for the first 5 years of the experiment (1897–1901) and the more recent long-term average (1976–2015). Public Library of Science 2017 surface SOC stocks fertilization effects plant species richness ammonium sulphate-induced acidification future fertilizer use ecosystem Steinach Grassland experiments fertilizer addition FYM Palace Leas Hay Meadow response 120 years 2017-03-28 18:45:13 Figure https://plos.figshare.com/articles/figure/Changes_in_mean_hay_yield_at_Palace_Leas_for_the_FYM_20_t_ha_sup_-1_sup_and_four_ammonium_sulphate-containing_fertilizer_treatments_for_the_first_5_years_of_the_experiment_1897_1901_and_the_more_recent_long-term_average_1976_2015_/4796131 <p>Changes in mean hay yield at Palace Leas for the FYM (20 t ha<sup>-1</sup>) and four ammonium sulphate-containing fertilizer treatments for the first 5 years of the experiment (1897–1901) and the more recent long-term average (1976–2015).</p>