Granulometric Evolution of Soils in Response to Their Fertilization with Crushed Rocks: Case Study of the Western Highlands Andosols Treated with Trachyte Powder

The present paper aims to highlight the consequence of the fertilization of soils with rock powder on their granulometric evolution. For that purpose, Andosols developed on trachyte in the upper part of the southern limb of the Bambouto Mountains were fertilized with trachyte powder at different rates, activated with water and incubated during nine months. The different treatments generate the granulometric evolution of soils. The increasing of the amounts of trachyte powder as same as the duration of the incubation process makes the evolution more significant. In the detail, that treatment induces the enrichment of the treated soils in silts particles in the expense of clay and sands. At the end of the process, soils with high amounts of sands and silts in general are engendered. The use of rock powder as fertilizers must be gainfully preceded by the acquisition of informations concerning their amounts in organic matters. In case of low amounts, a supply with organic fertilizers would be necessary.