On the French Atlantic coast, in Brittany and Normandy, huge limestone reefs have formed over the course of millennia. They were created from the thallus of the red alga Lithotamnium calcareum, supersaturated with calcium compounds, in water heated by the Golfstrom, at a depth of 20 do 100 m. Due to their red color, these algae are also called coral algae. When exposed to air, their red color changes to light gray.
Red algae are sedentary forms, they live on rocks in the depths of the seas, adhered to the ground with grippers. Rafy created by them, often hundreds of meters thick, is currently operated with small vessels. Red algae has a coarse-grained structure. After extraction, they are dried (the water content decreases with 20 do 5%), then it cleans and grinds to obtain a dusty formulation. Its main ingredient is calcium carbonate of organic origin, the magnesium content is also significant. It also contains many valuable micronutrients, in proportions similar to seawater. In addition, it shows a rich microbiological life. Breton farmers have been using this flour for several centuries, they call "maerl", as fertilizer and animal feed. When its production on an industrial scale was developed, its consumption in the countries of western and central Europe has clearly increased. Red algae preparations should not be overlooked in agriculture or horticulture, especially in special crops. They are sold under the name Algomin. They can be used in various ways. The algal lime spread over the soil surface improves its structure and water balance. Under the influence of Algomin, the content of calcium in the soil significantly increases, magnesium, as well as increasing the amount of micronutrients built into various complex organic compounds.
The deficiencies of many components in the soil can be replaced with Algomin, e.g.. used as a solution. Red algae preparations are also used for foliar fertilization of fruit trees; it was first used in this way in northern Italy. Algomin dusty is known in Germany. It can be spread by hand or with the use of dusters. In this way, diseases caused by fungi can be easily controlled, such as the potato blight, caused by Phytophtora infestam, and also fight harmful insects. The finely ground powder penetrates the pest's body and causes its death by dehydration. In the event of massive diseases or pests, the treatment must be repeated several times. The white spots on the leaves are not a disease symptom and they disappear quickly. This measure is not phytotoxic. If it is used for the first time to increase the content, is the dose, depending on pH, it should be 800-1200 kg / ha. If the preparation is used annually, 200-300 kg / ha is enough. 35-50 kg / ha are needed to dust the plants, and a concentration of liquid is used for spraying 2,5%. Be careful when spraying, that no grains of sand enter the sprayer pump.
The possibility of adding algae lime to the compost was mentioned earlier.