Mineral Absorption

Mineral nutrients present in soil exist in one of two states - either dissolved directly in the soil solution, or adsorbed onto the surface of colloidal clay particles - and their movement into living root cells, technically called mineral absorption (with entry into a cell termed influx and exit termed efflux), takes place not only through root hairs but through the root epidermis, or epiblema, more generally. It was once mistakenly assumed that mineral absorption simply travels along automatically with water absorption, but the two processes are now understood to be genuinely independent of one another - minerals do not necessarily enter root hairs together with water at all. A further complication is that the plasma membrane of root cells is not equally permeable to every kind of ion, and different ions belonging to the same dissolved salt are not absorbed at the same rate as each other, which is why several distinct theories - grouped broadly into pass …