Search results
Results from the WOW.Com Content Network
Soil bulk density is equal to the dry mass of the soil divided by the volume of the soil; i.e., it includes air space and organic materials of the soil volume. Thereby soil bulk density is always less than soil particle density and is a good indicator of soil compaction. [47] The soil bulk density of cultivated loam is about 1.1 to 1.4 g/cm 3 ...
Arable density (m² per capita) by country. This is a list of countries ordered by physiological density."Arable land" is defined by the UN's Food and Agriculture Organization, the source of "Arable land (hectares per person)" as land under temporary crops (double-cropped areas are counted once), temporary meadows for mowing or for pasture, land under market or kitchen gardens, and land ...
The physiological density or real population density is the number of people per unit area of arable land. A higher physiological density suggests that the available agricultural land is being used by more and may reach its output limit sooner than a country that has a lower physiological density. Egypt is a notable example, with physiological ...
Soil bulk density, when determined at standardized moisture conditions, is an estimate of soil compaction. [60] Soil porosity consists of the void part of the soil volume and is occupied by gases or water. Soil consistency is the ability of soil materials to stick together. Soil temperature and colour are self-defining.
In geotechnical engineering, a soil test can be used to determine the physical characteristics of a soil, such as its water content, void ratio or bulk density. Soil testing can also provide information related to the shear strength, rate of consolidation and permeability of the soil. The following is a non-exhaustive list of engineering soil ...
[71] [72] There may be a population limit of around one billion cells per gram of soil, but estimates of the number of species vary widely from 50,000 per gram to over a million per gram of soil. [73] [74] The number of organisms and species can vary widely according to soil type, location, and depth. [72] [74]
The Proctor compaction test is a laboratory method of experimentally determining the optimal moisture content at which a given soil type will become most dense and achieve its maximum dry density. The test is named in honor of Ralph Roscoe Proctor [de], who in 1933 showed that the dry density of a soil for a given compactive effort depends on ...
Soil gradation is a classification of the particle size distribution of a soil. Coarse-grained soils, mainly gravels or sands, are graded as either well graded or poorly graded. Poorly graded soils are further divided into uniformly-graded or gap-graded soils. Fine-grained soils, mainly silts and clays, are classified according to their ...