Impact of long-term organic and mineral fertilization on lucerne forage yield over an 8-year period

摘要

Effects of direct fertilization on lucerne (Medicago sativa L.)forage yield have been widely investigated;however there is a lack of published studies investigating the long-term effect of indirect application of mineral and organic fertilization. The main objective of the present research was therefore to investigate differences in forage yield under different combinations of mineral (6 treatments) and organic (3 treatments) fertilization over the past 8 years of long-term experiment conducted since 1955 in Ruzyně.Long-term absence of fertilization provided average annual dry matter yield of 8.64 t/ha. Indirect application of single manure or slurry significantly increased yield to 9.68 and 9.37 t/ha, respectively. Absence of mineral fertilization provided yield of 9.23 t/ha across organic fertilization and an inconsistent effect of the increase of indirectly applied nitrogen (N) rate was observed. The highest yields over 10 t/ha were observed at treatments where combinations of organic fertilization with higher rates of N, phosphorus (P) and potassium (K) were applied. The trend for yield reduction was observed under increasing N rates within identical P and K fertilization. This research has shown that indirect effect of fertilization should be considered together with stand age when lucerne forage yield is evaluated.