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Soil moisture equilibrium with relative humidity under different constant temperatures for clay and calcareous soils
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Abstract: A modified apparatus was used to study the effect of relative humidity (rh) on equilibrium moisture content (r), under different constant temperatures (Ko for two soils. A clay soil taken from Behera Governorate and calcareous soil from Nubaria. The chemical and physical prosperities of the two soils were determined. Different air temperatures inside the chamber and (rh) were recorded and (r) was determined. A quantitative approach was used.
where: () and (are constants, their values depend on soil type.
The calculated values in average for () and (were 1.2 x10-5 and 2.12 at temperature ranged between 290 and 314 (Ko) for clay soil, respectively, while the corresponding values for calcareous soil were 3.7 x10-4 and 1.431, at temperature ranged between 291 and 313 (Ko), respectively. So, the developed formula for clay soil took the form:
, while it was for calcareous soil.
The results indicated that exponential equations were definitely the more suitable to describe the relation between (rh) and (r). As expected, the results revealed that the (r) was increased with increasing (rh) for both clay and calcareous soils. With respect to soil types, the ( value for calcareous soil was greater than that of clay soil at the same range of air temperature, therefore the (r) for calcareous soil was less than that of clay soil. This could be attributed mainly to the difference of clay content (i.e. surface area), porosity and pore size for both kinds of soils. The (r) and (rh) were decreased with increasing temperature. Such decreasing was, however, varied within both soil types
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| URL |
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| Publication year |
2004
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| Pages |
145-156
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| Availability location |
Soils, Water and Environment Research Institute, ARC
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| Availability number |
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| Organization Name |
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| Country |
Egypt
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| City |
Alexandria
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| serial title |
J. Adv. Agric. Res. 9(1):.
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| Volume |
9
. 1
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| Department |
Soil Salinity and Alkalinity Res. Lab.
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| Author(s) from ARC |
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| Agris Categories |
Nature conservation and land resources
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AGROVOC
TERMS |
Calcareous soils.
Clay soils.
Relative humidity.
Soil water content.
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| Proposed Agrovoc |
temperatures;
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| Publication Type |
Journal
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