National Capital Cactus and Succulent Society (NCCSS)  by Donna
Kuroda   - Soils are essential for life on earth and critical in
many of the environmental challenges facing the earth.  Most
plants depend on soils as a suitable medium for growth by
providing at least six factors for plant growth:  physical
support for anchoring the root system, aeration and ventilation
for the roots, pores for absorbing rainwater and holding it for
use by the roots, moderation of temperature fluctuations,
protection from phytotoxic substances, and supplying inorganic
minerals in the form of dissolved nutrients.       - The four
major components of soil are air, water, mineral matter, and
organic matter.  An ideal soil for plant growth has a
composition by volume of 50% solid (45% mineral, 5% organic) and
50% pore space (25% filled with air and 25% filled with water).
Succulent Soils  - The most important consideration in making a
potting soil for succulents is that it will drain well.  The
soil must be porous so that water pe