Plants vs Soil
My background is in chemistry (used to teach years back).
I'm now an amateur gardener. What is the primary reason some plants
thrive in clay soils while others in sandy soils? I have searched the
Internet, and found a lot of information concerning the soils themselves,
but nothing about what plant root structures or cells that make the
plants more adaptable to either type of soil. Do sandy soil plant roots
need to have greater surface area since drainage is quicker?
Various plant species are adapted to different soil types and differing
amounts of clay, silt, and sand.
Possibly of interest:
Anthony Brach Ph.D.
This is a bit of a stretch of my areas of expertise, but at least four
factors come to mind:
1. You mention drainage which certainly is a factor.
There are actually two factors. The first is some plants like a wet root
system while others prefer a drier environment. In addition nutrients tend
to "wash away" in porous sandy soil so nutrient retention would play a role.
2. Soil packing would be another. Clay soils tend to pack tightly and some
plant roots to not have the "strength" to set their roots deeply enough for
sustained growth in densly packed soils.
3. My recollection is that clay
soils tend to have a lower pH (more acidic) than sandy soils and certainly
soil pH will affect growth. I'm sure there are other more subtle effects.
Your local Ag extension office probably has a lot of information on how
various plants respond to various soil types.
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Update: June 2012