Seaweed Fertilizers in Agriculture: How to Make, Benefits, NPK Ratio, and Disadvantages

Seaweed fertilizers, or kelp fertilizers, are natural fertilizers derived from seaweed used in agriculture for centuries. Seaweed contains various beneficial nutrients and minerals to enhance plant growth and improve soil health. In recent years, seaweed fertilizer has become more popular because it lasts longer and is better for the environment than traditional chemical fertilizers.

This article discusses the advantages/benefits, and negatives of kelp fertilizer and its benefits, preparation, and NPK ratio. Knowing the qualities of kelp fertilizer can help farmers of all sizes maximize their harvest’s productivity and quality.

Seaweed Fertilizers in Agriculture

What are Seaweed Fertilizers?

Seaweed fertilizers are natural soil amendments made from sustainable marine algae sources. It is approved for organic use and is a powerful tool in a gardener’s arsenal. Seaweed fertilizers can come in two forms, kelp meal, and liquid seaweed. Unlike chemical fertilizers, they contain high micronutrients, minerals, and organic matter that promote healthier plants. Seaweed is a great way to promote plant vigor, produce more abundant fruits and vegetables, and improve soil quality by supporting beneficial microorganisms. By using seaweed fertilizer, you can enhance plant growth and development, increase soil fertility, and reduce the use of synthetic chemicals in your garden.

History of Seaweed Fertilizers

Seaweed, a type of algae that grows in oceans, has over 10,000 species and plays a vital role in marine ecology. Unlike terrestrial plants, seaweed cells can directly take up nutrients from surrounding water, and all cells can photosynthesize. Seaweeds have cultural significance and economic value, making their production a major industry in coastal nations.

By using seaweed fertilizers in gardens, individuals can support regenerative farming practices and the growth of the seaweed industry. Some recommended seaweed fertilizers for gardening include Espoma Organic Kelp Meal, Bloom City CleanKelp Seaweed Fertilizer, Neptune’s Harvest Seaweed Fertilizer, and Seaweed Bliss Soluble Seaweed Extract.

How to Make Seaweed Fertilizers

You can use either newly harvested seaweed collected from the ocean or dried seaweed purchased from a gardening shop to create seaweed fertilizer.
Once you’ve collected your kelp, give it a good rinsing under running water to get rid of any traces of salt or sand. Second, cut or snip the seaweed into manageable segments.
Once the seaweed is chopped up, add a container with water to the pail. Please soak the seaweed for several days until the water goes brown and has a pungent odor. The seaweed is soaked to extract the elements and nutrients that it contains.
After a few days, pour the juice through a sieve or cheesecloth to remove the seaweed. Nutrients and elements from the seaweed are extracted and concentrated in the resulting liquid.
To use the seaweed fertilizer, dilute the liquid with water at a ratio of 1:5 (one part seaweed liquid to five parts water). This helps to prevent the fertilizer from being too strong and potentially harming the plants.
Finally, apply the diluted seaweed fertilizer to your plants by watering them with it or applying it directly to the soil around the plant’s base.

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Benefits of Seaweed Fertilizer in Agriculture

Seaweed fertilizer is an organic fertilizer produced by accurately processing marine plants such as seaweed as the primary raw material. It is a natural and nutrient-rich fertilizer that offers many benefits to agriculture.
Firstly, seaweed fertilizer contains many essential nutrients that plants require for growth and development. It contains 40 kinds of minerals, such as potassium, calcium, magnesium, iron, zinc, and iodine, and abundant vitamins, which are unmatched by terrestrial plants.
Secondly, the active ingredients in seaweed fertilizers are easily absorbed by plants. They enter the plants within 2 to 3 hours after application. This speedy absorption and conduction velocity are due to the alginic acid in seaweed fertilizer, which reduces the surface tension of water and forms a layer of film on the plant’s surface, increasing the contact area and making the nutrients in the seaweed extract more accessible to plants.
Thirdly, seaweed fertilizer can improve soil quality by directly increasing soil organic matter through soil or plants and activating various microorganisms. These microorganisms can act as catalysts in the circulation of plant-microbial metabolites, increasing the biological effectiveness of the soil.
Fourthly, seaweed fertilizer has a long-lasting fertilizing effect due to the chelation system formed by seaweed polysaccharides and humic acid, which can release nutrients slowly and extend fertilizer efficiency.
Lastly, seaweed fertilizer is safe and non-toxic. The raw materials used in seaweed fertilizer are derived from natural seaweeds, making them non-toxic and harmless to humans and livestock.

NPK Ratio of Seaweed Fertilizers

Seaweed fertilizers are a great source of micro-nutrients and growth hormones for plants. Liquid seaweed is non-burning and can be used in every watering, while kelp meal is best added to soil as a supplement. All-purpose seaweed fertilizers like Maxsea have higher N-P-K numbers but can burn plants incorrectly.

Maxsea has a balanced pH and is an affordable option for hydroponic gardens. Supplement with Cal-Mag or Epsom salt for fast-growing plants to provide extra calcium and magnesium. Concentrated seaweed extracts like Nitrozime can be used as a foliar spray or nutrient additive. Still, they should only be used by experienced growers who understand the basic N-P-K ratios.

How to Use Seaweed Fertilizers

Seaweed fertilizer comes in two forms: powder and liquid. The powder form can be mixed into soil or sprinkled on top, while the liquid form is more expensive and needs to be diluted before use. Diluted liquid fertilizer can be used to drench roots or spray onto leaves. It’s important to follow the recommended dilution ratio on the product packaging.

Soak plants in a seaweed solution for 1-2 hours or overnight for best results. Carefully follow the manufacturer’s instructions and make a test application before using it widely throughout the garden. Seaweed fertilizer suits various plants, including vegetables, flowers, fruit trees, and potted plants.

Disadvantages of Seaweed Fertilizers

First, they can be expensive compared to traditional fertilizers. Second, the high salt content in some seaweed fertilizers can harm certain plants if not properly diluted. Third, the odor of seaweed fertilizers can be strong and unpleasant. Finally, using seaweed from polluted waters can introduce toxins into the soil.

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Conclusion

Seaweed fertilizers offer numerous benefits in agriculture, including improved plant growth, disease resistance, and carbon sequestration. They can be easily made at home and have a favorable NPK ratio. However, they can be expensive, have a strong odor, and have high salt content if not properly diluted.

Seaweed Fertilizers in Agriculture: How to Make, Benefits, NPK Ratio, and Disadvantages