Marine calcium (marine sediment) 
Calcareous marine sediment mined from deposits, with remains of seaweed and marine worms (polychaetes), sold in Mexico by Ecoagro.
Characteristics
- Analysis published by the maker: pH 7.66, electrical conductivity 2.83, ash 76.99%, organic matter 23.01%, carbon 13.35%, sulphates 29% (sulphur 9.67%), calcium 27.1% (calcium oxide 37.94%).
- Advantages put forward by the maker: enriching the soil with calcium, sulphur and organic matter, and helping to bring saline soils back into production; it shows demonstration plots reclaimed in Sinaloa.
- According to the maker, the activity of marine worms enriches the material with organic matter, humic and fulvic acids and microbial flora.
- Ecoagro also uses it as a complement in its blends.
Role in the preparation: Supplies calcium, sulphur and organic matter to soil, compost or mineral blends.
Caution: Commercial product whose composition is documented only by the maker: ask for a recent batch analysis, including salinity. Wear a mask when handling the powder.
Sources: Ecoagro (Guamúchil, Sinaloa, México) — ficha técnica «Calcio marino» · Remineralize the Earth — The Ecoagro Revolution in Mexico (2018)
Documentary information: this is neither a recommendation for use nor a plant-protection or veterinary claim. Check your country's regulations before any use.