To maintain species‐rich swards from which forage of a high nutritional quality can be produced, it is essential to adapt grassland fertilization strategies. In this study, we investigated how different long‐term mineral fertilization treatments affect dry‐matter (DM) yield, plant species composition, and nutrient and mineral concentrations of forage from mountain grasslands. During 2 years, forage was sampled from three different long‐term fertilization experiments located at 930 (L), 1,190 (M) and 1,340 (H) m a.s.l. at different sites in Switzerland. At each site, three mineral fertilization treatments (0, PK and NPK) had been maintained for three to six decades, with two (L and M) or three harvests (H) per year. Yield, the botanical composition and concentrations of net energy, utilizable crude protein and different phenolic fractions were determined. Nutrient and mineral concentrations were also determined. For all three sites (L, M and H), unfertilized swards had lower annual DM yields (3.39, 5.17 and 2.73 t/ha) compared to PK (6.33, 7.17 and 4.44 t/ha) and NPK fertilized swards (7.69, 7.22 and 7.44 t/ha), respectively. Long‐term fertilization had little effect on the gross nutrient and phenolic composition, but forage P and K concentration increased. The decades‐long fertilization of either PK or NPK of up to 85 kg N, 80 kg P₂O₅ and 240 kg K₂O/ha reduced plant species richness only at site H. Fertilization of PK may allow to simultaneously increase forage productivity and maintain forage quality in mountain grasslands.

中文翻译：

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几十年来，零，PK和NPK矿物施肥的物种丰富的高山草原的牧草质量

为了维持可产生高营养品质牧草的物种丰富的草皮，调整草地施肥策略至关重要。在这项研究中，我们调查了不同的长期矿物施肥处理措施如何影响干草原（DM）产量，植物物种组成以及高山草地牧草的养分和矿物质浓度。在2年中，从三个不同的长期施肥实验中取样了草料，分别位于瑞士不同地点的930（L），1,190（M）和1,340（H）m asl。在每个站点，三到六十年一直维持三种矿物施肥处理（0，PK和NPK），每年两次（L和M）或三个收获（H）。产量，植物成分和净能量浓度，确定了可利用的粗蛋白和不同的酚类馏分。还确定了营养和矿物质的浓度。与PK（6.33、7.17和4.44 t / ha）和NPK施肥的草皮（7.69、7.22）相比，这三个地点（L，M和H）的未施肥草皮的年DM产量（3.39、5.17和2.73 t / ha）都较低。和7.44吨/公顷）。长期施肥对总养分和酚类成分影响不大，但饲草中磷和钾的含量增加。长达85公斤N，80公斤P的PK或NPK长达数十年的施肥 长期施肥对总养分和酚类成分影响不大，但饲草中磷和钾的含量增加。长达85公斤N，80公斤P的PK或NPK长达数十年的施肥 长期施肥对总养分和酚类成分影响不大，但饲草中磷和钾的含量增加。长达85公斤N，80公斤P的PK或NPK长达数十年的施肥₂ O ₅和240 kg K ₂ O / ha仅在站点H处降低了植物的丰富度。PK的施肥可以同时提高草场的牧草生产力并保持草场质量。