Sustainable Soil Management
Glossary
E
ECOSYSTEM. Community of animals and plants and the physical environment in which they live.
EFFLUENT. Discharge or emission of a liquid or gas.
ELEMENTAL SULFUR. Sulfur in the elemental form that must be oxidized by soil microbes to the sulfate form for plant uptake.
ELLICTRICAL CONDUCTIVITY. The capacity of a substance to conduct or transmit electrical current. In soils or water, measured in siemens/meter (or often dS/m), and related to dissolved solutes.
ELUVIATION. The removal of materials such as clays, organic matter, iron, or aluminum from a horizon.
ENTISOLS. An order in Soil Taxonomy. Soils that have no diagnostic pedogenic horizons. They may be found in virtually any climate on very recent geomorphic surfaces.
EROSION. The wearing away of the land surface by running water, wind, ice, geological agents or mechanical actions, such as tillage or land leveling.
ESSENTIAL PLANT NUTRIENTS. Inorganic elements required for growth and development of plants.
EUTROPHICATION. A natural process of enrichment of aquatic systems by nutrients, primarily nitrogen and phosphorus. Accelerated, or cultural, eutrophication is caused by the addition of excess nutrients to a system. This results in excessive vegetative growth. Decomposition of this plant material can result in the depletion of oxygen in water, leading to the death of aquatic organisms.
EVAPOTRANSPIRATION (ET). Loss of water to the atmosphere from the earth’s surface by evaporation and by transpiration through plants.
EXCHANGEABLE IONS. Positively or negatively charged atoms or groups of atoms that are held on or near the surface of a solid particle by attraction to charges of the opposite sign, and which may be replaced by other like-charged ions in the soil solution.
