Seaweed biostimulants – a solution towards a regenerative and sustainable agriculture

Biostimulants are one of the most innovative alternatives for those who want to improve the yield, quality, and post-harvest shelf-life of agricultural products and promote the sector's sustainability. Biostimulants include a diverse array of microorganisms or organic material that helps the plants to thrive, even under stressing environmental conditions, by improving water and nutrient uptake and protecting them against pathogens. Furthermore, biostimulants can, directly and indirectly, contribute to a reduction in the use of synthetic chemicals that could be detrimental to the benefic plant and soil microorganisms.

Among the naturally derived plant biostimulants, seaweed gains momentum as they are highly nutritious, have fast growth rates, and no need for freshwater, pesticides, or chemicals throughout its cultivation. Seaweeds have been used in agriculture and horticulture directly or mixed with other fertilizing ingredients for many centuries, enhancing crop productivity and soil fertility. Besides, many seaweed species are economically and ecologically important, providing hydrocolloids and other precious compounds for the pharmaceutical, cosmetic, food, and feed industries.

Liquid biostimulants or sap can be extracted from seaweed before biomass enters the industrial production chain, such as carrageenan extraction industry. Kappaphycus sp. is the most extensive culture species of seaweed for the production of carrageenan. However, Kappaphycus sap, or k-sap, also has phytohormones that positively affect plants, fruits, and seeds, improving plant productivity. Thus, this seaweed can provide an exciting and practical solution toward regenerative and sustainable agriculture, reducing or even eliminating the use of synthetic fertilizers or pesticides.

Kappaphycus alvarezii has been successfully applied in crops and horticulture through different modes of application. The seed treatments with small doses of K. alvarezii extract helped increase the length of roots and shoots of soybeans and improved germination of rice, peanuts, and chilli. In this latter study, the combination of seedling treatment with foliar application of 2% of liquid K. alvarezii fertilizer resulted in a yield increase of 27% and 33% for rice and chilli, respectively, while 1% of foliar spray increased the yield of peanuts in 30,6%. Foliar application of K. alvarezii has also improved the yield and quality of wheat, sugarcane, maize, tomatoes, bananas, and several other vegetable crops. Besides the positive effects on plant health, growth, and quality, K. alvarezii can also regulate tomatoes' immunologic response against fungus.

The applications of Kappaphycus as biostimulants are still a new trend within the agricultural sector. However, the results are promising and certainly indicate its great potential as a biostimulant in a diversity of cultures. If you want to try with your cultures, get in contact with us and request trial information.