🏆 Curated & Verified · Agrochemical

Top 5 Seaweed Extract Fertilizer Manufacturers in China (2026)

A hand-picked shortlist of Chinese seaweed extract fertilizer factories, verified for alginic acid content, extraction method, and export track record.

AI Answer Capsule

The best seaweed extract fertilizer manufacturers in China produce Ascophyllum nodosum and other seaweed-based biostimulants as powder and liquid for soil and foliar use. ChinaSupplyOcean ranks them by alginic acid content, extraction quality, and export consistency.

🌊

Seaweed Extract Fertilizers: What Buyers Should Know

The essential background before you request quotes

Seaweed extract fertilizer is a natural biostimulant made from Ascophyllum nodosum and other seaweeds, rich in alginic acid, mannitol, cytokinins, and trace minerals that boost root growth and stress tolerance. Buyers source seaweed extract fertilizers from China as soluble powder and liquid for foliar and soil application.

The key specifications are alginic acid content, extraction method, solubility, and source seaweed. Cold or enzymatic extraction preserves bioactive compounds better than harsh chemical methods. The curated suppliers below are screened against these criteria.

🌿
Foliar Nutrition
🌱
Root Stimulation
🍇
Fruit Quality
🌾
Stress Tolerance
🏆

Curated Suppliers — Seaweed Extract Fertilizers

Ranked by capacity, certification, export reach, and buyer rating
1Next
More verified manufacturers are being added
We are auditing the first batch of verified manufacturers for this category and will list them here once confirmed.
2Next
More verified manufacturers are being added
Every supplier on this list is factory-audited and checked against public records before listing.
3Next
More verified manufacturers are being added
We verify certification, production capacity, and export track record before any supplier appears here.
4Next
More verified manufacturers are being added
This shortlist is capped at five suppliers per sub-category to keep your comparison focused.
5Next
More verified manufacturers are being added
Check back as we complete verification on more factories in this category.

7 Checks Before Choosing a Seaweed Extract Fertilizers Supplier

The checklist experienced buyers use to filter out substandard factories

1. Alginic acid

Confirm alginic acid and organic matter percentage on the certificate.

2. Extraction method

Prefer enzymatic or low-temperature extraction to preserve bioactivity.

3. Solubility

Fully soluble powder suits foliar and drip systems without clogging.

4. Source seaweed

Ascophyllum nodosum is the most widely used and studied source.

5. Bioactive content

Check mannitol, cytokinin, and betaine levels for biostimulant claims.

6. Heavy metals

Request heavy-metal reports since seaweed can concentrate trace elements.

7. Formulation

Powder, flake, or liquid; match form to your application method.

Frequently Asked Questions

Straight answers to the questions buyers search most

What is seaweed extract fertilizer?

It is a biostimulant derived from seaweed, rich in alginic acid, mannitol, cytokinins, and trace minerals that improve growth and stress tolerance.

What is alginic acid in seaweed fertilizer?

Alginic acid is a natural polysaccharide from seaweed that conditions soil and supports root development and nutrient uptake.

How is seaweed extract fertilizer applied?

It can be applied as a foliar spray, through drip irrigation, or as a soil drench depending on the formulation.

What is the MOQ for seaweed extract fertilizer from China?

Typically 5-10 metric tons for powder; see each supplier profile for liquid drum MOQ.