Search results
Results from the WOW.Com Content Network
With the addition of an equal volume of 0.02 M to the soil suspension that was prepared for the water pH, the final soil-solution ratio is 1:2 0.01 M . A 20-g soil sample is mixed with 20 mL of reverse osmosis (RO) water (1:1 w:v) with occasional stirring.
Soil acidification is the buildup of hydrogen cations, which reduces the soil pH. Chemically, this happens when a proton donor gets added to the soil. The donor can be an acid , such as nitric acid , sulfuric acid , or carbonic acid .
The centimetre (SI symbol: cm) is a unit of length in the metric system equal to 10 −2 metres ( 1 / 100 m = 0.01 m). To help compare different orders of magnitude , this section lists lengths between 10 −2 m and 10 −1 m (1 cm and 1 dm).
The AASHTO Soil Classification System was developed by the American Association of State Highway and Transportation Officials, and is used as a guide for the classification of soils and soil-aggregate mixtures for highway construction purposes.
The pH range is commonly given as zero to 14, but a pH value can be less than 0 for very concentrated strong acids or greater than 14 for very concentrated strong bases. [2] The pH scale is traceable to a set of standard solutions whose pH is established by international agreement. [3]
The original Proctor test, ASTM D698 / AASHTO T99, uses a 4-inch-diameter (100 mm) by 4.584-inch-high (116.4 mm) mold which holds 1/30 cubic feet of soil, and calls for compaction of three separate lifts of soil using 25 blows by a 5.5 lb hammer falling 12 inches, for a compactive effort of 12,375 ft-lbf/ft 3.
CEC is the amount of exchangeable hydrogen cations (H +) that will combine with 100 grams dry weight of soil and whose measure is one milliequivalent per 100 grams of soil (1 meq/100 g). Hydrogen ions have a single charge and one-thousandth of a gram of hydrogen ions per 100 grams dry soil gives a measure of one milliequivalent of hydrogen ion.
Topsoil is composed of mineral particles and organic matter and usually extends to a depth of 5-10 inches (13–25 cm). Together these make a substrate capable of holding water and air which encourages biological activity.