Revisiting a 37 years abandoned fertilizer experiment on Nardus grassland in the Czech Republic

A set-aside experiment on sub-alpine Nardo-Caricion rigidae grassland was identified in the Giant Mts. (Krkonoše, Karkonosze), in which Ca, N and P fertilizers were each applied at three rates on five occasions from 1965 to 1967; since that time plots remained abandoned. In 2004, the effect of all fertilized treatments on sward structure was still visible 37 years after the last fertilizer application. Avenella flexuosa and Anthoxanthum alpinum were the dominant species in phosphorus fertilized plots whereas Nardus stricta was the dominant species in the control as well as in the limed and nitrogen fertilized treatments. The biomass production of A. alpinum was higher in all fertilized treatments than in the control but significantly only in one P treatment. The lowest amount of dead aboveground biomass was found in all P fertilized plots followed by two Ca treatments. P, Ca and NO3− concentrations in the biomass were highest in P treatments and Ca concentration was higher, but non-significantly differing from control, also in two Ca treatments. Soil pH was highest in two Ca treatments and was affected by soil Ca concentration.