To obtain a culture material for promoting fertilizer retention, the maintenance of ground temperature, heat retaining properties, the activation of microorganisms or the like, improvement and stabilization of soil, assimilation and fusion of soil in the natural world.

This culture material is obtained by mixing a biological microorganism with fine powder of activated carbon such as bamboo charcoal, charcoal, etc., mineral fine powder having a far infrared effect, combining and uniforming. The three particular characteristics and the synergistic effects of the characteristics can provide a composite culture material promoting the activation of microorganisms, adjustment function of PH/EC concentration, assimilation and fusion of soil in the natural world and having fertilizer retention, heat retaining properties, air permeability, drainage, etc.