Biochar and deactivated yeast as seed coatings for restoration: performance on alternative substrates

Biochar and deactivated yeast are potential sustainable, low-cost materials with high nutrient- and water-holding capacity that could be used in this context as seed coatings to aid in seedling establishment on challenging substrates. We conducted a greenhouse study to assess the effectiveness of biochar and deactivated yeast, applied alone in a factorial combination, as seed coatings, on the germination, establishment, and early growth of white clover (Trifolium repens) and purple prairie clover (Dalea purpurea).

Coated seeds were applied to a mine tailing, a coarse granitic sand, and potting soil mix substates; seedling establishment and growth were monitored over 75 days. Results indicate strong interactive effects of seed coating type with effects of species and substrate. Biochar coatings enhanced germination of Trifolium, while yeast coatings did so for Dalea.