AFS
American Foundrymans Society Average Fineness Number is used to denote the relative grading of sand. AFS is calculated using the old BS mesh numbering system for sieves. In general lower figures denote coarser material. The value does not give any indication for the distribution of particle sizes.
 
AGS
Average Grain Size is used to denote the relative grading of sand. AGS is calculated using micron sieve sizes. In general lower figures denote finer material. The value does not give any indication for the distribution of particle sizes.
 
Bulk density
Mass or weight, including air space, of a sample (usually but not always oven dried,) usually expressed as g/cm3
 
Capillary porosity
Smaller pore space, generally filled with water. (see Total Porosity)
 
Cation exchange capacity (CEC)
Ability to hold onto nutrients by electrical attraction, measured as the total amount of exchangeable cations which can be held, usually expressed as meq/100g
 
Clay
Inorganic mineral fraction less than 2 microns in diameter.
 
Dolomite
Sedimentary rock composed mainly of calcium-magnesium carbonate as CaCO₃,MgO₃.
 
D Value
Particle size diameter at which a given cumulative percentage of material is indicated to pass. e.g. If D90 = 650 microns this would indicate that 90% of material is smaller than 650 microns.
 
Free lime content
Percentage by weight of solid carbonate in the form of calcium as CaCO₃ and/or calcium-magnesium (dolomite) as CaCO₃,MgCO₃.

Gradation index
Indicates the degree of uniformity for a particle size distribution analysis. Two common ratios used are D90/D10 and D60/D10 Low result indicates a uniform particle size distribution whereas a high result indicates a wide spread of particle sizes which can lead to interpacking.
 
Gravel
Granular aggregate material between 60 and 2 millimetres in diameter.
Coarse Stone between 60 and 50 millimetres in diameter.
Medium Stone between 50 and 20 millimetres in diameter.
Fine Stone between 20 and 8 millimetres in diameter.
Coarse Gravel between 8 and 4 millimetres in diameter.
Fine Gravel between 4 and 2 millimetres in diameter.

Lignite
A brownish-black coal in which the alteration of vegetable matter has proceeded further than in peat but not so far as in bituminous coal.
 
Limestone
Sedimentary rock composed mainly of calcium carbonate as CaCO3.
 
Micron
Micron is the shortened name for micrometre. There are 1000 micrometres in a millimetre.
 
Non-capillary porosity
Larger pore space, generally filled with air. (see Total Porosity)
 
Organic matter content
The percentage by weight of organic constituents. This may include plant and animal tissues (living and dead) and their partial decomposition and synthesis.
 
pH
Measurement of relative acidity or alkalinity expressed in terms of the pH scale of which, values less than 7 are acidic, greater than 7 are alkaline and 7 is neutral. (see Free Lime Content)
 
Rootzone
Prepared blend of sand and organic/inorganic amendment for use as a medium in the development of turfgrass rooting. The blend should offer desired physical properties for use in the construction of sports turf areas.
 
Sand
Inorganic mineral fraction between 2000 and 63 microns (2.0 and 0.063mm) in diameter.
Very Coarse Sand between 2000 and 1000 microns in diameter.
Coarse Sand between 1000 and 500 microns in diameter.
Medium Sand between 500 and 250 microns diameter.*
Fine Sand between 250 and 125 microns in diameter.*
Very Fine Sand between 125 and 63 microns in diameter.*
Note that USGA defines sand as:
Inorganic mineral fraction between 2000 and 53 microns (2.0 and 0.053mm) in diameter.
Very Coarse Sand between 2000 and 1000 microns in diameter.
Coarse Sand between 1000 and 500 microns in diameter.
Medium Sand between 500 and 250 microns diameter.
Fine Sand between 250 and 150 microns in diameter.
Very Fine Sand between 150 and 53 microns in diameter.

Saturated hydraulic conductivity
The constant rate at which a saturated rootzone, sand or soil is able to transmit water downwards, usually measured in mm/hr.
NB Hydraulic conductivity, in an unsaturated rootzone will decrease as water content decreases.
 
Silica
The chemically and physically resistant dioxide of silicon [SiO2] which occurs naturally as quartz, flint, chert, opal, or chalcedony and combines in silicates as an essential constituent of many rock-forming minerals.
 
Silt
Inorganic mineral fraction between 63 and 2 microns in diameter.*
Coarse Silt between 63 and 20 microns in diameter.
Fine Silt between 20 and 2 microns in diameter.
* Note that USGA defines silt as:
Inorganic mineral fraction between 53 and 2 microns in diameter.

Soil
Areas of the Earth's surface that support plants, consisting of inorganic mineral matter, organic material, air and water. The varying properties are determined by the integrated effects of climate and the conditions under which they were formed.
 
Thatch
An organic layer of dead leaves, stem bases, roots, stolons and rhizomes, in various stages of decay lying on top of the mineral soil, it also contains living roots etc. of the turf. Thatch is a natural development in all turf when earthworms are absent. It has a high lignin content and so resists microbial breakdown.
 
Top dressing
Prepared blend of sand and organic amendment which is designed to sustain or augment the rootzone profile. Top dressings are applied to the surface of a sports turf area for purposes of amelioration and to improve the trueness of the surface.
 
Total porosity
Total pore space which is filled with air and/or water. Total pore space may account for 35% - 55% of a material depending on texture, structure and compaction.

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