| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a block, a powder body or a grain body obtained by hydration-hardening a mixture of natural humic with iron (powder or grain) or an iron-containing mineral component with a curing agent and useful for the project of fisheries in such a manner that pest is suppressed in plant culture, and seawater-damage is suppressed by releasing ionized fulvic acid iron and mineral ions.SOLUTION: By using powder body or grain body obtained by hydration-hardening a mixture of natural humic and iron (powder or grain) or an iron-containing mineral component with a curing agent for a crop land, or submerged-installing a molded block or powder body to a water area, a land or a sea area releasing the fulvic acid iron and mineral ions for a long period and enough in various mineral ions can be made. Further, a powder body, a grain body or a block obtained by being added with seed, a fertilizer and organisms upon the hydration hardening can be used for agriculture and cultivation.</p> |
