Antelo Rodríguez, MaiteIllera Vives, MartaFernández Labrada, MiguelSeoane Labandeira, SocorroLópez Mosquera, María Elvira2023-01-232023-01-232022Rodríguez, M.A., Illera-Vives, M., Labrada, M.F. et al. Improving growing substrates by adding the seaweed Cystoseira baccata. J Appl Phycol 34, 3177–3188 (2022). https://doi.org/10.1007/s10811-022-02846-40921-8971http://hdl.handle.net/10347/29979We examined the impact of adding the seaweed Cystoseira baccata (Ochrophyta, Sargassaceae) in various forms to two different growing substrates: pine bark and gorse compost. Specifically, we examined the influence of the seaweed on the physical and chemical properties of the substrates, and on their agronomic performance on a lettuce crop. The seaweed was used in a 20% (v/v) proportion and three different forms, namely: fresh (FS), washed fresh (WFS), and washed and dried (WDS). The mixed substrates exhibited no signs of instability. FS and DWS increased the total water retention capacity of pine bark by 20% and 27%, respectively. Adding the seaweed in any of its three forms to this type of substrate, which is poor in nutrients and has a low electrical conductivity (EC), significantly increased its P, K, Mg and Na contents, as well as its EC (from 0.08 dS m–1 in the control substrate to 0.69, 0.12 and 0.27 dS m–1 in those containing FS, WFS and WDS, respectively). On the other hand, only in fresh form (FS) altered the salinity and total K content of a substrate rich in nutrients and salts such gorse compost (from 0.89 to 1.42 dS m−1 in terms of EC and 0.59% to 0.98% in K). All mixtures performed well as substrates for a lettuce crop. Those containing DWS increased aerial mass in gorse compost, while any of the tested formats increased aerial mass in pine barkeng© 2022 The Authors. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/Atribución 4.0 Internacionalhttp://creativecommons.org/licenses/by/4.0/Brown seaweedGrowing mediaPhysical propertiesSalinityGerminationLettucejournal article10.1007/s10811-022-02846-41573-5176open access