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That's not quite accurate.
Soil capacity is soil capacity, and the closer it is to saturation the less water can be added.

However, there are certain conditions that reduce initial infiltration rates. Bare soil, when first struck by raindrops, will often form a crust at the surface due to movement of clay and silt particles to fill the pore spaces at the surface.
Also, in semiarid and (more often) arid environments, an impermeable K horizon can form below the A horizon. This is a leading cause of flash floods in deserts.

Tallgeese wrote:

That's not quite accurate.
Soil capacity is soil capacity, and the closer it is to saturation the less water can be added.

take a damp sponge and a dry sponge.
Pour a cup of water over them.

The wet sponge will hold more than the dry sponge.

I'm gonna take a wild guess here and say that Texans probably slow down or in some other way alter their driving style when the roads are wet.

Not so in California. It's surprising any of us are alive.

In other Comcast-related news, I'm told a friend of my mother's, who lives in SF, finally got sick and tired of having so few cable channels to choose from, so today she called Comcast to complain. They determined that she'd cancelled her service back in June!

Last edited by Bren (2009-10-13 5:06 pm)

You know, I wasn't looking to start an argument but to share some information from my area of expertise, but...

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*Water Content: The content or amount of water in the soil affects the infiltration rate of the soil. The infiltration rate is generally higher when the soil is initially dry and decreases as the soil becomes wet. Pores and cracks are open in a dry soil and many of htme are filled in by water or swelled shut when the soil becomes wet. As they become wet, the infiltration rate slows to the rate of permeability of the most restrictive layer.

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The infiltration rate is the velocity or speed at which water enters into the soil. It is usually measured by the depth (in mm) of the water layer that can enter the soil in one hour. An infiltration rate of 15 mm/hour means that a water layer of 15 mm on the soil surface, will take one hour to infiltrate.

In dry soil, water infiltrates rapidly. This is called the initial infiltration rate. As more water replaces the air in the pores, the water from the soil surface infiltrates more slowly and eventually reaches a steady rate. This is called the basic infiltration rate.

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Inherent - Infiltration rate is dependent on soil texture (percentage of sand, silt, and clay) and clay mineralogy.Water moves more quickly through the large pore spaces ina sandy soil than it does through the small pores of aclayey soil, especially if the clay is compacted and haslittle or no structure or aggregation (see Table 1).Depending on the amount and type of clay minerals, manyclayey soils develop shrinkage cracks as they dry, creatinga direct conduit for water to enter the soil. These clay soilshave high infiltration capacities as water moves into theshrinkage cracks, although at other times, when cracks arenot present, their infiltration rate is characteristically slow. Dynamic - A reflection of climate and landscape position, as well as management practices and cropdemand, existing soil water content affects the ability ofthe soil to pull additional water into it. Pores and cracksare generally open in a dry soil. Many of them are filled inby water or swelled shut as the soil becomes wet, soinfiltration rate is generally highest when the soil is dry. Asthe soil becomes wet, the infiltration rate slows to the rateat which water moves through the most restrictive layer,such as a compacted layer or a layer of dense clay.Infiltration is affected by crop and land managementpractices that affect surface crusting, compaction, and soilorganic matter. Without the protective benefits ofvegetative or residue cover, bare soil is subjected to thedirect impact and erosive forces of raindrops that dislodgesoil particles. Dislodged soil particles fill in and blocksurface pores, contributing to the development of surfacecrusts that restrict water movement into the soil.

I love this rain! I'm also happy to be on the second floor right now.

:waits for one or more trees to fall:

resedit wrote:

I don't care about the technical details.
The fact remains that damp soil will hold water better than dry soil and you can easily test it.

I'd recommend hushing up and just accepting what he has to say. The fact is, Tallgeese knows more about soil than probably anybody else here, and that includes myself and the farmers.