Productivity, Biodiversity and Forage Value of Meadow Sward Depending on Management Intensity and Silicon Application

The efficiency and quality of meadows is affected by, among others, the botanical composition of the sward and the frequency of cutting. The research was conducted in 2023–2024 on the experiment established in 2014 on arable land, where 3-species mixtures of grasses and legumes were sown. During the next three years, the sward was fertilized and cut 3-times per year, and then, for five years, was mown twice a year, without fertilization. On the sward formed at that time, in 2023, an experiment was established to evaluate how management intensity (2- or 3-cuts and rate of fertilizer) and silicon application (Si or 0Si) affect botanical composition, yield, and nutrient content in perennial meadow swards under variable precipitation over two years. Species richness rose in the sward in the second year, especially under 3-cut management (from 15 to 21 species). The share of species sown earlier in the mixtures Dactylis glomerata, Festulolium braunii, and Medicago x varia was very high at both management intensities (66–87% DM). Yield and the content of crude protein and nutrients were higher in the 3-cut system in the second and third regrowths. Silicon supplementation increased plant diversity and yield resilience during drought, with more intensive management supporting sustainable forage production. Moreover, the sward contained more nutrients with 3-cuttings in the second and third regrowths. These findings indicate that intensive meadow management and silicon application enhance productivity, forage value, and biodiversity, providing valuable insights for sustainable meadow management strategies.