Soil Science Flashcards
Having a pH less than 7.0
Acid
Group of soil bacteria resembling fungi; actinomycetes Play a role in the decomposition Of organic matter and the release of mineral elements
Actinomycetes
Adhesion on contact of the molecules of gases, dissolved substances, or liquids to the surface of solids or liquids with which They are in contact
Adsorption
Provision of air to the soil to allow root and microbial respiration
Aeration
Close cluster and/or mix of small particles of soil and or organic matter of varying sizes that are bonded together
Aggregate
Having a PH greater than 7.0
Alkaline
State or quality of being alkaline
Alkalinity
Ion that carries a negative charge
Anion
Water remaining in the soil after gravitational water has drained and before the Permanent wilting point has been reached
Available water
Minute, usually single celled organisms having a cell wall but no organized nucleus and reproducing by fission; some species are plant pathogen’s
Bacteria
Ability of a soil to maintain i.e. resist change in its pH
Buffering capacity
Mass of soil per unit volume; used as a measure of soil compaction; often written as grams/cubic centimeter (g/cm3)
Bulk density
Water held in the capillary pores of the soil; much of this water can move in any direction and is readily available to plant roots
Capillary water
Positively charged ion; NN soils, the most abundant cations are calcium (Ca) magnesium (Mg) potassium (K) sodium (Na) and aluminum (Al)
Cation
Ability of a soil to absorb and hold cations; affected by soil organic matter and particle size; a measure of soil fertility and clay composition
Cation exchange capacity (CEC)
Chemical compounds that keep plant nutrients usually iron (Fe) and manganese (Mn) soluble and available for plants absorption over a broad range of pH
Chelates
(1) soil particles with a typical grain size less than 0.004 MM; (2) A soil predominantly composed of such particles
Clay
Predominantly negatively charge soil particles of clay and hummus that absorb cat ions; when positively charged, anions Are absorbed; storage site for plant nutrients
Colliod
Closely or firmly packed or join together
Compaction
Organic matter that has been intentionally subjected to decay or decomposed to the point of not being recognizable as the regional parent material
Compost
Pertaining to plant nutrients, lack or insufficient Quantity of a required element
Deficiency
Process of reducing nitrates to nitrogen gases
Denitrification
Type of mycorrhizae that grows between the cortical or epidermal cells of absorbing roots, forming an outer sheath around the roots
Ectomycorrhizae
Type of mycorrhizae that grows within route cells, also referred to as vesicular-Arbuscular (VA) mycorrhizae (VAM)
Endomycorrhizae
Minerals essential to the growth and development of trees; these minerals are essential because plants cannot complete their life cycle without them
Essential elements
An oozing from pores or breaks in cell membrane
Exudation
Maximum soil moisture content following the drainage of water due to the force of gravity
Field capacity
Water that drains from soil macropores due to the force of gravity
Gravitational water
Layer of soil within the soil profile
Horizon
Dark colored, stable form of organic matter that remains after most of the plant or animal residue have decomposed
Humus
Crystalline polymers that absorb water and, if needed, can be added to the soil to increase its water holding capacity
Hydrogels
Study of the properties, distribution, and effects of water on the earth surface, underground, and the atmosphere
Hydrology
The physical or chemical property of a molecule or substance that is attracted to water (and may be dissolved in water)
Hydrophilic
The physical or chemical property of a molecule or substance that repels water
Hydrophobic
Retained water that is held to tightly in soil for update by plants
Hygroscopic
Surface that does not allow for infiltration and or penetration of liquids
Impervious
(1) Downward entry of water into the soil; (2) entry of fine particles into drainage or aeration systems; can lead to system clogging and failure; (3) downward entry of materials from one soil or fillet or to another, as when a gravel road surface mixes with underlying soil
Infiltration
Speed at which water penetrates the soil
Infiltration rate
Atoms or a group of atoms with a positive or negative charge
Ion
(1) Tendency for elements or compounds to wash down through and or out of the soil; (2) tendency for elements Or compounds to wash into the soil
Leach (leaching)
Soil texture classification based on a balanced ratio of sand silt and Clay; considered ideal for plant growth
Loam
Essential element that is required by plants in relatively large quantities such as nitrogen (N) phosphorus (P) potassium (K) and sulfur (S)
Macronutrients
Relatively large space between soil particles that is usually airfield analyze from water movement in route penetration
MacroPore
Essential elements that is required by plants and relatively small quantities such as iron (Fe) manganese (Mn) zinc (Zn) copper (Cu) and boron (B)
Micronutrient
Space between soil particles that is relatively small and likely to be water filled
Micropore
Naturally occurring, and organic solid that has a definite chemical composition and possesses characteristic physical properties; certain minerals are considered essential elements for tree growth and development
Mineral
Process in which an organic substance is converted to or trapped In a inorganic substance
Mineralization
Symbiotic association between certain fungi and absorbing roots of plants
Mycorrhizae
Substance that provides nourishment essential for the growth and maintenance of life; implants, often used synonymously with essential elements
Nutrient
Movement of mineral elements sometimes called nutrients with an Ecosystem as organic matter decomposers, releasing found nutrients back to plants
Nutrient cycling
Condition in which the supply or availability of an essential element causes cessation of critical plant Processes, resulting in visible, physical symptoms such as chlorotic leaves or necrotic margins, and which, if left untreated, will reduce tree health and may eventually lead to premature death
Nutrient deficiency
Condition in which the supply or availability of an essential element reduces the growth rate but does not cause plant dysfunction or premature death
Nutrient limitation
Layer of organic matter at the soil surface
Organic layer
Material derived from the growth and death of living organisms; the organic components of soil
Organic matter
Diffusion of water through a semi permeable membrane from a region of higher water potential (lower salt concentration) to a region of lower water potential (higher salt content concentration)
Osmosis
Pressure generated by the movement of water across the cell membrane caused by the difference between solute concentrations on each side
Osmotic pressure
Soil bread rock or base material from which a soil profile develops
Parent material
Movement of water through the soil
Percolation
Point at which a plant cannot pull any more water from the soil and suffers permanent damage
Permanent wilting point
Allowing liquids or gases to pull through, as with a membrane or material
Permeable
Penetrable; allowing passage through; often used to describe surfaces
Pervious
Soil area immediately adjacent to, and affected by, plant roots; typically has a high level of microbial activity
Rhizosphere
Soils with a high concentration of soluble salts; Can cause poor plant health
Saline soil’s
Soils with high concentrations of fell soluble salts (saline) and sodium ions (sodic)
Saline-sodic salts
Soil particles are the size between 0.06 mm and 2.0 mm in diameter
Sand
Point at which a soil or an aquifer will no longer absorb any amount of water without losing an equal amount
Saturation point
Mineral elements, such as calcium (Ca) and magnesium (Mg), required in moderate amounts by plants
Secondary nutrients
Soil particles with a grain size between 0.004 mm in 0.062 mm (coarser than clay particles but finer than sand)
Silt
