Autor(es): Machado, Rui M.A. ; Alves-Pereira, Isabel ; Alves, Inês ; Ferreira, Rui M. A. ; Gruda, Nazim S.
Data: 2024
Identificador Persistente: http://hdl.handle.net/10174/37572
Origem: Repositório Científico da Universidade de Évora
Assunto(s): Lactuca sativa; soilless system; short-cycle crops; municipal compost; biochar; total phenols; flavonoids; ascorbic acid; circular economy
This research aimed to assess the influence of reusing coir-based substrates on growth, nutrient content, and phytonutrients accumulation in lettuce. The experiment included a new coir pith and four coir-based mixes (1) coir, biochar, and perlite; (2) coir, compost, and perlite; (3) coir, biochar, and pine bark; and (4) coir, compost, and pine bark. All mixes had been previously utilized to grow transplanted spinach and possessed identical ratios of 78:12:10% (v/v) among their components. Lettuce (Lactuca sativa L. cv. ‘Godzilla’) seedlings were transplanted into Styrofoam plant boxes. Each day, the planting boxes received a nutrient solution via drip irrigation. Plants grown in reused mixes had similar macronutrient concentrations as those grown in coir for the first time, except for N and K in the third mix. Plants grown in reused mixtures had similar yields as those in new coir. Lettuce heads yielded 4.6–4.9 kg/m2, while plants grown in reused mixtures had equal or higher total phenols than those in new coir. Ascorbic acid content was higher in plants cultivated in reused mixes. Coir-based growing media can be reused for another short-cycle crop, like lettuce, without yield loss or phytonutrients decrease.
