Feldspar's role in providing soil with macronutrients k and ca (example: Wadi El-Annab Northeast of Algeria)

Abstract

Feldspars are an abundant mineral group and make up about 60% of the earth's crust. They are present in many sedimentary deposits and are found in almost all igneous and metamorphic rocks. The crust-mantle interaction at the plate boundary and inside the plate is the primary source of these minerals. Common feldspars include orthoclase (KAlSi3O8), albite (NaAlSi3O8), and anorthite (CaAl2Si2O8). Weathering of feldspars is important in soil formation, especially for increasing soil fertility for food production. The Feldspar group of minerals is an important mineral to sustain life on the Earth. The feldspar group minerals play an important role in the overall dynamics of macronutrients such as K and Ca in soils. The massif of Wadi El-Annab is made up of igneous rocks. This massif is surrounded by the forest from all sides and a big part of this massif is covered with plants. This region is characterized by significant rainfall and a good hydrographic system. This study of massif by thin sections shows that it consists mainly of feldspar groups, quartz, micas (biotite and muscovite) and calcite as a secondary mineral. The feldspar group includes orthoclase and plagioclases. The plagioclases represent 50% of all feldspar. The orthoclase represents 50% of all feldspar. The feldspars are altered and show microfractures. The alteration of the feldspars is mainly because of water while the microfractures are because of the incursion of plant roots in the floor.