Price of horticultural vermiculite

　　Vermiculite is a mica-like material formed by silicate materials heated at high temperature. In the heating process, the water quickly loses and expands, and the volume after expansion is 8-20 times that of the original volume. Thus, the material can increase the ventilation pore and water retention capacity. The volume weight of horticultural vermiculite is 130-180 kg/cubic meter, which is neutral to alkaline (ph7-9). Vermiculite absorbs 500-650 litres of water per cubic meter. Appropriate amounts of potassium, calcium and magnesium can be released after steam disinfection.

　　As a horticultural vermiculite, its main function is to increase the aeration and water retention of soil (medium). Because of its fragility, with the extension of the use time, it is easy to make the medium dense and lose ventilation and water retention, so the use time of coarse vermiculite is longer than that of fine vermiculite, and the effect is good. Therefore, vermiculite for horticultural use should be chosen as thinner sheet vermiculite, even if the medium for seeding fine seeds and as cover for seeding are better than thicker sheet vermiculite.