Agrogeological and mineralogical characteristics of the soil from experimental fields of the Institute of Agriculture-Kyustendil, Bulgaria

Abstract

Four main and two secondary feeding provinces with minerals and soil forming material are determined: Bistritsa River feeding province, Struma River feeding province, Struma Diorite Formation feeding province and Neogene Conglomerate Sandstone feeding province. Montmorillonite from the clay minerals, quartz, magnetite, and chlorite shales are determined as the most important agricultural minerals for the studied soils. Quartz has property of creating electrical energy under the influence of external factors such as pressure, shock, heat, friction, chemical reactions, etc. make it a prime suspect as a source of energy and electrical impulses in soil, which are very important for cation exchange between soil and plant roots and for converting some substances into others, incl. of inorganic chemical compounds in organic. Quartz determines the basic granular composition of the soil and determines the moisture absorption, plasticity, moisture performance, etc. It helps maintain constant temperature and acidity of the soils. Magnetite associates with carbonates and quartz and by this way marks secondary mineralization due to adsorption processes in the soil and speaks of the participation of magnetite in cation exchange processes in the soil. The mineral magnetite is also related to the microbial composition of the soil. Chlorite shale as well as Montmorillonite can, under certain conditions, release chlorine and thus, together with the released sodium described above, NaCl salt is formed, which is the mineral halite or otherwise table salt, which salinized the soil and leads to damage to agricultural production, worsens the quality and storage life of the fruit and finally leads to the death of the plants and economic loses. In these cases it is needed to use gypsum agricultural mineral fertilizer for neutralization of the salt and its drainage.