Plant Bioestimulants: Compost Tea and Bioslurry Characterization

Abstract In the present study, the quality of aerated and non-aerated compost teas and bioslurry as bio-fertilizers and its application on two plant species in different substrates were tested. Compost tea brewed from a mixture residues compost presented higher nutrient content than that brewed from grape marc composted. Aeration, with shorter extraction time, resulted in higher pH, but in general with lower nutrient concentration, while bioslurry, presented higher nitrogen content. No pathogen and toxic effects were detected in the bio-products. Finally, Bio-products were evaluated in ornamental plant species: Petunia hibrida and Impatiens walleriana , where compost teas and bioslurry presented highly variable properties and effects on plant growth, depending on the substrate and species used. While in sand no significant effect on plant biomass and pigments were observed, in compost and commercial substrate bioslurry presented values similar to the traditional fertilizer. Compost tea presented variable results with no differences between aerated and non-aerated, both increasing carotenoids in I. walleriana in sand. We conclude that aeration showed no differences in compost tea quality, whilst bioslurry demonstrated to increase plant biomass at similar values to traditional fertilizer. Our results demonstrated that alternative products are an efficient, safe, ecological, and economical alternative to traditional products.