Seaweed-based boosters from Galicia help crops cope with heat, drought and salt

Around 400 tonnes of seaweed go through Porto-Muiños every year, a company in Cerceda, in Galicia (north-west Spain), that prepares it for people to eat. Some of it used to be discards or species with no commercial value. After nearly four years of work, the BIO_MARTERRA operational group, set up by the company, has turned those leftovers into a crop biostimulant that, its developers say, helps plants withstand drought, heat and, in greenhouses, salty conditions. The tests were small-scale, the results were presented on 22 October at the Biological Mission of Galicia (MBG-CSIC) in Salcedo, Pontevedra, and no study has been published so far.

From seaweed scraps to the field

The team tested the extract in the lab, in greenhouses and in the field, at different doses and with different ways of applying it, on tomato, lettuce, pepper, potato and grapevine. One of the challenges was adapting the processing so the product met the rules for this kind of farm input. Manuela Buján, from Porto-Muiños’ R&D department, summed it up at the event: “We have successfully produced an extract that complies with current regulations and have demonstrated – on a small scale, under both controlled conditions and in the field – that it effectively mitigates various plant stressors, including drought, heat, and salinity.”

Two farmers who took part, Avelino Santana (Patatas A Corga) and Néstor Liñares (Horta da Lousa), shared their field results.

Atlantic seaweed against downy mildew

At the Biological Mission, CSIC’s VIOR group (Viticulture, Olive and Rose), led by researcher Carmen Martínez, studied Atlantic seaweed extracts against grapevine downy mildew. The goal is to cut the number of applications of the plant protection products now used in vineyards to control disease-causing fungi. According to the MBG, lab results are “clear and promising”; positive effects have also been seen in the field, but they need more years of testing.

Funding from the EU, Spain and Galicia

The project received €179,634.83: 80% from the European Agricultural Fund for Rural Development (EAFRD), 16% from Spain’s Ministry of Agriculture, Fisheries and Food and 4% from the Galician regional government. Alongside Porto-Muiños and MBG-CSIC, the group includes the FEUGA foundation, which coordinates it, a unit of the University of Santiago de Compostela and farmer Avelino Santana, with support from the Mabegondo Agricultural Research Centre and Horta da Lousa.

The next step is the market: the MBG describes these products as close to commercialisation, and Porto-Muiños has opened a new line of business around them.

Photos of the trials, provided by the VIOR group, will be added to this story.