Soil Science Terms and Definitions, Quizzes of Geography

Download Soil Science Terms and Definitions and more Quizzes Geography in PDF only on Docsity! TERM 1 parent material DEFINITION 1 The inorganic material base from which soil is formed. TERM 2 soil DEFINITION 2 A natural terrestrial surface layer that contains minerals and organic matter and that supports, or is capable of supporting plants, animals, and microbial communities. TERM 3 regolith DEFINITION 3 The layer of rock and mineral particles that lies above bedrock. TERM 4 humus DEFINITION 4 Dark brownto black organic matter on or in the soil, consisting of fragmented plant tissues partly digested by organisms. TERM 5 soil horizon DEFINITION 5 A distinctive layer of soil, more or less horizontal, set apart from other layers by differences in physical or chemical composition. TERM 6 soil profile DEFINITION 6 A display of soil horizons on the face of a freshly cut vertical exposure through the soil. TERM 7 soil enrichment DEFINITION 7 Additions of materials to the soil body. TERM 8 illuviation DEFINITION 8 The accumulation in a lower soil horizon of materials brought down from upper horizons. TERM 9 calcification DEFINITION 9 The accumulation of calcium carbonate in a soil, usually occurring in the B or C horizons. TERM 10 gleyzation DEFINITION 10 Iron and manganese compounds are reduced in the soil, creating streaks of blue, results from a hard pan of calcification that occurs in cold climates. TERM 21 soil colloid DEFINITION 21 An extremely small mineral or organic particle that can remain suspended in water indefinitely. TERM 22 bases DEFINITION 22 Positively-charged plant nutrients ions; base cations. TERM 23 cation-exchange capacity DEFINITION 23 The ability of soil to hold and exchange cations (positively charged mineral ions); determines fertility of soilwater solution for plants. TERM 24 entisols DEFINITION 24 Mineral soils without distinct horizons. TERM 25 Inceptisols DEFINITION 25 Weakly developed horizons usually because the soil is young. TERM 26 Alfisols DEFINITION 26 Mature soils characterized by a clay rich B horizon produced by illuviation. TERM 27 Spodosols DEFINITION 27 Soil formed in the cold boreal forest climate beneath a needleleaf forest. TERM 28 Ultisols DEFINITION 28 Soil that is exposed to warm temperatures and high rainfall, so it is highly weathered and leached of nutrients. TERM 29 Oxisols DEFINITION 29 Soils of moist climates of the equatorial, tropical, and subtropical zones on land surfaces that have been stable for long periods. TERM 30 Mollisols DEFINITION 30 Grassland soils that occupy vast areas of semiarid and subhumid climates in midlatitudes. TERM 31 Aridisols DEFINITION 31 Soil that is characteristic of deserts and are dry for much or all of the year. TERM 32 Gelisols DEFINITION 32 Soils of cold regions that are underlain by perennially frozen ground, or permafrost. TERM 33 Vertisols DEFINITION 33 Soil with a unique set of properties that contrast sharply with Oxisols and Ultisols. TERM 34 Andisols DEFINITION 34 Soils where more than half of the parent material is volcanic ash. TERM 35 Histosols DEFINITION 35 Unique soil that has a high content of organic matter in a thick, dark upper layer.