• Can Liquid Seaweed Fertiliser Replace Synthetic Fertiliser?

Fuel for Thought

Can Liquid Seaweed Fertiliser Replace Synthetic Fertiliser?

May 31 2023

Liquid seaweed fertiliser is an intriguing player in the world of plant nutrition. Often overlooked in favour of more conventional options, its potential as a sustainable and organic alternative to synthetic fertilisers is substantial. Manufactured predominantly from kelp, this type of fertiliser is known for its comprehensive nutrient profile and environmentally friendly harvesting processes. 

Liquid seaweed fertiliser provides an impressive variety of benefits for plant growth and health. It contains more than 70 minerals, vitamins and enzymes, essential for optimal plant development. The key nutrients—magnesium, potassium, zinc, iron and nitrogen—present in seaweed are crucial for various plant processes, including photosynthesis. 

This organic fertiliser promotes budding and extends the shelf life of fruits and vegetables when applied before harvesting. The extract enhances the longevity of cut flowers, serves as an efficient rooting solution, and increases the nutrient uptake and quality of pasture crops. 

Fascinatingly, seaweed extract also improves resistance of plants to frost and disease, enhances the uptake of inorganic constituents from the soil, bolsters resilience to stress conditions, and minimises storage losses of fruit. It's a game-changer in organic gardening, offering the micro-nutrients in a readily available form and promoting robust growth while deterring pests and diseases. 

The efficacy of liquid seaweed as a fertiliser is more than just anecdotal evidence. Numerous studies have substantiated the array of benefits it provides for plant growth and health. Researchers have found that seeds soaked in seaweed extract germinate more rapidly, exhibit stronger growth, larger root mass, and better survival rates. This treatment even reduces transplant shock, quickens root growth and enhances crop yields. 

Liquid seaweed fertiliser also contributes to plant health through plant hormones—auxins, cytokinins, betaines and gibbelerins. These hormones, present in small but potent quantities, are indispensable for plant health. For instance, auxins regulate growth speed and prevent untimely bud formation, while cytokinins activate basic growth processes and protect from frost and ageing. Betaines enhance water uptake, providing resilience in dry conditions and under stress. 

One distinguishing advantage of liquid seaweed fertiliser is the flexibility it offers in terms of application and concentration. For instance, foliar application—a method of spraying the fertiliser directly onto plant leaves—has been found to be 8-20 times more effective than soil application. Moreover, the concentration of this fertiliser can be varied based on plant needs, offering a tailored approach to plant nutrition. 

Liquid seaweed fertilisers are produced from various seaweed species, ensuring minimal environmental impact. Harvesting methods are optimised for sustainability, with the processing methods designed to harness the natural benefits of seaweed immediately upon application. The production process involves no harmful chemicals, making it an organic product extensively tested in grower trials. 

In the UK, the use of seaweed fertiliser is already quite widespread. It is used in traditional farming methods in Scotland and the Channel Islands and is popular in maintaining the English and Scottish Football Premiership Grounds, as well as numerous UK Championship Golf Courses. 

Today, as concerns mount over the environmental implications of synthetic fertilisers, seaweed fertilisers are emerging as an attractive sustainable alternative. They contain essential nutrients in balanced proportions, enhancing crop yield and quality while being economical and eco-friendly. 

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