Egardening

Taking a close look at my soil texture here in South East Oakville

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1. Digging a new garden plot

2. Random samples were taken of the top soil layer  uppermost 20cm

3. About 5.5cm of loose soil was placed in a 1L mason jar - corresponding to about 33dL.

4. 50dL or water was added and the jar shaken vigorously.

5 After 10 minutes the sand layer had settled and measured approximately 5.3cm (unfortunately the jar was on a table which was clearly not level)

6. After 1 hour approximated 0.175 cm of silt settled on the sand now slightly compressed to 5.cm

7. After 12 more hours a barely visible layer of clay had settled on the silt layer - perhaps 0.025 (This is certainly not rigorous measurement, as the slant makes apparent). The sand layer had now separated into a distinct grey layer at the base and a browner lighter layer of sand above.

This soil is 96% sand, 3.25% slit and 0.75% clay.

"Soil texture is crucial because it affects several aspects of plant growth and development:

• the rate at which water will percolate through the soil
• the ease with which the soil may be tilled
• the ability of the soil to provide nutrients for good plant growth under stress conditions.

In sand that has a uniform particle size, large pore spaces (macropores) are present between the soil particles.

When enough of these large sand particles exist in a soil, they touch each other. Through their bridging action they maintain the large pore spaces even under heavy watering or foot traffic. A sandy loam soil, on the other hand, contains smaller silt and clay particles as well as large sand particles. Smaller pore spaces (micropores or capillary pores) form between the silt and clay particles.

The macropores and micropores form a network of interconnecting, irregular tubes or tunnels that honeycomb the soil matrix. Oxygen, carbon dioxide, and other gases move into, through, and out of the soil through this network of pore spaces. The more open are the spaces between the pores - i.e., the more air there is filling the pores -- the more rapid are the movement of gas and exchange of air. Such a condition is called good soil aeration." (Notes from  Erin Winchur, Cultural Practices for Plants, Guelph University 2008).