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Name: Freddy
Status: student
Grade: 4-5
Location: FL
Country: USA
Date: N/A 


Question:
How do different soils types hold water?



Replies:
Freddy

I think this article will answer your questions for you. Just click on it and your browser should launch and take you to this site:

http://en.wikipedia.org/wiki/Soil_water_%28retention%29

Here is the answer to your question from the article:

The spaces that exist between soil particles, called pores, provide for the passage and/or retention of gasses and moisture within the soil profile. The soil's ability to retain water is strongly related to particle size; water molecules hold more tightly to the fine particles of a clay soil than to coarser particles of a sandy soil, so clays generally retain more water (Leeper and Uren, 1993). Conversely, sands provide easier passage or transmission of water through the profile. Clay type, organic content and soil structure also influence soil water retention For example, sand has a lot of space between its grains and water can collect in those spaces Whereas soil compacted really hard such that it becomes metamorphic igneous rock doesn't have any room to store water.

Sincere regards,
Mike Stewart


Freddy,

The ability of soil to hold water depends on several factors, but particularly on it's composition and the amount of air space (porosity) within it.

Soil can be composed of mineral and organic parts, often characterized as clay, silt, and sand. Clay particles are generally very small, sand particles are generally very large, and silt particles are medium size.

A very sandy soil is not capable of holding water well, whereas soil with a high clay content is very good at holding water. The difference between them is not so much the amount of air space between the soil particles as it is the size of the air spaces in the soil. In high clay soils, the air spaces are more numerous and much smaller than in sandy soils, making it hard for water to drain out. Water can more easily drain through high sand content soil than through high clay content soil. Therefore, high clay content soil retains water much more easily than doe high sand content soil.
--
David R. Cook
Meteorologist
Climate Research Section
Environmental Science Division
Argonne National Laboratory



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