摘要：Organic grassland farmers are caught between the pressure to operate profitably and theneed to ensure ecosystem services like nature conservation. Phosphorus (P) management isat the core of this dilemma: grassland legumes, which are vital for nitrogen (N) inputs, foragequantity and quality, have high P requirements. However, rising soil P contents lead todecreased phytodiversity. We examined this ‘P dilemma’ based on data of a study in typicalorganically managed grasslands in north-eastern Germany. We found a slight, but notsignificant negative correlation between the soil P contents and phytodiversity. Such anegative correlation was much clearer in broader ecological studies of European grasslands,probably due to a scale effect. Despite comparably small P concentrations, we detected onlymoderate species richness. Thus, other factors besides P concentrations are limiting phytodiversity here, probably N concentrations. The P concentrations in the biomass of variouslegume species indicated P limitations for most of them. We conclude that a bundle ofadapted management measures could reconcile economic and environmental requirementsof organic farmers to a certain degree and thus lessen the conflict between the twoecosystem services ‘biodiversity’ and ‘forage production’.
