Use of seed balls as a technique to improve seedling emergence and establishment in an area degraded by the disposal of urban solid waste

Direct seeding is used for the restoration of extensive areas, but seed germination, seedling stabilization, and survival depend on the development of adequate techniques. This study evaluated plant emergence, survival, establishment, and growth using seed balls with different substrates for the restoration of a decommissioned landfill area in the municipality of Diamantina, Minas Gerais, Brazil. Seed balls made with manure and 45%, 60%, and 75% clay, containing seeds of four tree species and two herbaceous species, composed the treatments with low (T1), medium (T2), and high (T3) clay content. Seedling emergence was assessed after 60 days, and survival, establishment, and growth (final height − initial height) were evaluated after 12 months. Seed balls containing 60% clay (T2) resulted in the highest seedling emergence and height growth, while survival and establishment were generally greater in the treatments with medium and high clay contents than in the low-clay treatment. Overall, the medium-clay formulation provided the most favorable balance among the evaluated recruitment indicators. Under the environmental conditions of this study, seed balls containing 60% clay improved early plant recruitment and establishment, indicating their potential use in the initial stages of ecological restoration of degraded areas.