Soil Sciences: Definitions and Functions of Soil and Its Components, Quizzes of Agricultural engineering

Download Soil Sciences: Definitions and Functions of Soil and Its Components and more Quizzes Agricultural engineering in PDF only on Docsity! TERM 1 Components of the Global Ecosystem DEFINITION 1 Atmosphere Biosphere hydrosphere lithosphere TERM 2 Atmosphere DEFINITION 2 Air surrounding the Earth TERM 3 Biosphere DEFINITION 3 Environment in which living organisms are found and interact TERM 4 Hydrosphere DEFINITION 4 Total body of water that exists on or close to the surface of the Earth TERM 5 Lithosphere DEFINITION 5 Upper (oceanic and continental) layer of the solid Earth TERM 6 Pedosphere DEFINITION 6 The envelope of the Earth where soils occur and where soil-forming processes are active. TERM 7 5 Factors of Soil Formation DEFINITION 7 Climate Living organisms Parent material Topography/relief Time TERM 8 Soil boundaries DEFINITION 8 Upper boundary Lateral boundary Lower limit TERM 9 Upper Boundary DEFINITION 9 Generally considered as air-solid surface interface or free water-solid surface interface TERM 10 Lateral Boundary DEFINITION 10 Deep water or barren areas of rock, ice, salt, or shifting desert sand dunesSediments at depths greater than were emergent plants grow are not considered as soil TERM 21 Soil Fertility DEFINITION 21 Concerned with the quality of a soil that enables it to provide nutrients in adequate amounts in proper balance for the growth of specified plants or crops.(agriculture) TERM 22 Soil Chemistry DEFINITION 22 Deals with the chemical constitution, chemical properties, and chemical reactions of soils.(applied toward waste management or agriculture) TERM 23 Soil Conservation DEFINITION 23 Concerned with the protection of the soil against physical loss by erosion or against chemical deterioration; that is, excessive loss of fertility by with either natural or artificial means. TERM 24 F.A. Fallou DEFINITION 24 Founder of Soil Science(1794-1877) TERM 25 V.V. Dokuchaev DEFINITION 25 Father of Modern Soil Science(1846-1903) TERM 26 E.W. Hilgard DEFINITION 26 "Father of American Soil"(1833-1893) TERM 27 H. Jenny DEFINITION 27 Published "Factors of Soil Formation"(1899-1992) TERM 28 Climate DEFINITION 28 Primarily precipitation and temperature TERM 29 Parent Material DEFINITION 29 Rocks and minerals or organic residues that give rise to soil. Determines the mineralogy and hence nutritional status of the soil. TERM 30 Topography DEFINITION 30 Slope, aspect and landscape position TERM 31 Biotic Factor or Living Organisms DEFINITION 31 Native vegetation Microorganisms, soil animals, and human beings TERM 32 Time DEFINITION 32 the period of time since the parent materials began to undergo soil formation TERM 33 6 ways Parent Material is Transported DEFINITION 33 Alluvial - transported by rivers/stream Collovial - transported by gravity Eolian - wind deposits Lacustrine - lake deposits Marine - sea or ocean bottom deposits Glacial - deposited by melting glacier TERM 34 Alluvial DEFINITION 34 Transported by Rivers/Streams (Floodplain) TERM 35 Collovial DEFINITION 35 Transported by Gravity TERM 46 Acid Solution DEFINITION 46 presence of added hydrogen ions in soil solution accelerates weathering TERM 47 Dissolution DEFINITION 47 Water hydrated the cations and anions until they become dissociated from each other and surrounded by water molecules TERM 48 Oxidation-reduction DEFINITION 48 Elements such as iron, manganese, or sulfur that are part of the mineral structure may change oxidation state depending on whether conditions in the soil are oxidizing or reducing. TERM 49 Complexation DEFINITION 49 organic acids in soils form chemical complexes with minerals This could sometimes result in the removal of certain elements from the mineral TERM 50 "ACTIVE FACTORS" DEFINITION 50 Climate Living Organisms TERM 51 Most important Climatic Parameters are: DEFINITION 51 1. Temperature - Organic matter production increases as temp increases, provided there is rainfall for good plant growth 2. Precipitation - When rainfall increases, organic matter production increases provided the temp is high enough for good plant growth. TERM 52 Living Organisms are responsible for: DEFINITION 52 Organic matter decomposition Biochemical weathering Soil profile mixing Development of soil physical properties TERM 53 Slope Aspect DEFINITION 53 Affects the degree of exposure to the sun which influences the moisture content of the porous material Affecting organic mater decomposition and the degree of weathering More advance soils are on flat lands TERM 54 Trends that happen on the soil with Time DEFINITION 54 It becomes deeper, develops distinct layers, becomes more acidic Usually becomes redder and most of the nutrients are leached by percolating rainwater causing them to be less fertile Soils can erode away, be buried, or even become the parent material for a new soil TERM 55 Soil Horizon DEFINITION 55 A soil horizon is a layer generally parallel to the soil surface, whose physical characteristics differ from the layers above and beneath. soil horizon boundaries are usually initially determined by soil color boundaries TERM 56 Soil Profile DEFINITION 56 A vertical section of soil from the surface through all of its horizons and extending into the parent material TERM 57 Soil Solum DEFINITION 57 Part of the soil profile that contains the roots or influenced by plant roots TERM 58 Pedon DEFINITION 58 Smallest volume that can be called a soil TERM 59 4 General processes of how soil Profile changes DEFINITION 59 Addition to the soil Losses from the soil translocations within the soil transformations with the soil Important Note: all of the process are going on at the same time in the soil. They are working together to form different horizons. TERM 60 Epipedons DEFINITION 60 Diagnostic horizons that occur at the surface TERM 71 Oa DEFINITION 71 sapric soil materials Highly decomposed organic materials TERM 72 Oe DEFINITION 72 Hemi soil materials Partially (moderately) decomposed organic materials TERM 73 Oi DEFINITION 73 Fibricsoil materials Slightestdecomposed organic materials TERM 74 Criteria for A Horizons DEFINITION 74 Granular structure Typically dark in color TERM 75 Typical subordinate distinction of A horizon DEFINITION 75 Ap - plowing or other disturbance TERM 76 Field criteria for E Horizons DEFINITION 76 Lighter in color than over or underlying horizon TERM 77 Subordinate Distinctions of E horizon DEFINITION 77 Eg - strong Fleeing (color of matrix: >= 4/2) Ex - fragipan, dense, restrictive horizon TERM 78 Field criteria for B horizon DEFINITION 78 Blocky, prismatic, columnar In well drained soils it has the brightest colors TERM 79 Common subordinate distinction of B horizon DEFINITION 79 Bt - accumulation of clay (clay context 5% or higher from A) Bg - strong Gleying (matrix color: > 4/2) Bs - illuvial accumulation of susquioxides(iron) (Spodic) sandy Bh - illuvial accumulation of humus-feel greasy(Spodic) sandy Bss -Slickensides (highly cracked) low permeability Bk - Accumulation of CaCO3 (Calcic) Bx - brittle pan, usually loamy textured, dense TERM 80 Field Criteria for C Horizon DEFINITION 80 No structure development Massive or single-grained TERM 81 Well Drained DEFINITION 81 No redox features within 48" from surface TERM 82 Moderately well drained DEFINITION 82 Redox features between 24 - 48" TERM 83 Somewhat Poorly Drained DEFINITION 83 Redox features between 12 - 24" TERM 84 Poorly Drained DEFINITION 84 A Horizon < 12" think with gray colors dominant below A horizon TERM 85 Very Poorly Drained DEFINITION 85 >10" Black surface underlying by gray colors (matrix is gray) Has an O horizon TERM 96 Mollisol DEFINITION 96 oll Grasslands Common in Oklahoma Base saturation of >50% to an impermeable layer or at 1.8m from the surface Dark, think, good structure 7% of global ice-free land area TERM 97 Alfisol DEFINITION 97 alf Forest soils of cool moist climates Light colored, slightly to moderately acid with illuvial layer high in silicate clays Younger than Ultisol making it more fertile 10% of global ice-free land area TERM 98 Inceptisol DEFINITION 98 ept 15% Exchangeable sodium Young Soils, with only horizons that form quickly 17% of global ice-free land area ( highest) TERM 99 Entisol DEFINITION 99 ent Soil garbage bin Very young soils Slopes16% of global ice-free land area TERM 100 Soils 3 phases in system DEFINITION 100 Air (20-30%) Water (20-30%) Solids Inorganic/mineral fraction (45%) Organic fraction (5%) TERM 101 Saturation DEFINITION 101 Theocratic condition where all the pores are filled with water.Air is totally excluded from the pores and the effective supply of oxygen to soil is halted TERM 102 Major differences between soil air and atmosphere air DEFINITION 102 Soil air is not continuous Soil air has lower oxygen content and has higher carbon dioxide content than atmospheric air. TERM 103 What happens when pores are devoid of air DEFINITION 103 Microbial activity is affected nutrient fates are affected/chemical speciation changes - Nitrate could undergo denitrification Plant growth is affected Changes in soil morphology - redoximorphic features are formed TERM 104 Primary Minerals DEFINITION 104 Derived directly from solidification of magma sand TERM 105 Secondary Minerals DEFINITION 105 From the alteration of primary minerals Clay and Silt TERM 106 Types of Rocks DEFINITION 106 igneous rocks Sedimentary rocks Metamorphic rocks TERM 107 Humus DEFINITION 107 refers to the fraction of soil organic matter that is amorphous and without the "cellular structure characteristic of plants, micro-organisms or animals." Humus significantly influences the bulk density of soil and contributes to moisture and nutrient retention. TERM 108 3 factors that control Decomposition DEFINITION 108 Substrate (quality) - composition of organic material Environment - temp, availability of moisture/drainage, natural vegetation, disturbance, and aeration Soil-borne organisms - activity of microorganisms TERM 109 6 Functions of organic matter in the soil DEFINITION 109 Source of essential elements Substrate of most soil organisms Provides the distinct black color of soils that improve the soils ability to absorb the suns heat energy Improves soil physical properties Contributes to retention of water, nutrients and contaminants Good buffer against pH changes