Influence of cutting date on botanical composition and yield of species-rich lowland meadows in south Germany

摘要

Species-rich lowland hay meadows are a characteristic landscape element of grassland in south Germany and arc protected by the European Habitats Directive as 'habitat type 6510'. The conservation status of these meadows is frequently reported to be unfavourable - farmers are often unsatisfied with the biomass yield and forage quality. This study considers the effect of postponing the date of the first cut from mid-May to the beginning of July on plant diversity, forage yield and quality. This was investigated with four different cutting dates at two sites from 2013 to 2015. Annual mean dry matter yield (5.2 t ha~(-1)) was found to be only slightly affected by cutting date. The percentage of first growth in annual yield increased from 50% in the early cut to 63% in the late cut. Crude protein and net energy content declined by 43 and 21%, respectively. After 3 years, the number of species was highest in the mid-May cut, but only slightly lower in the later cuts. This suggests that early cutting maynot be the only factor endangering biodiversity. However, it may take several years before these effects become evident in permanent grassland through suppressed propagation.