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2. Soil Fundamentals
Supplies
•
A metal ring 6 inches in diameter by 5 inches in height (called an “infiltration ring”). Contact
your local soil water conservation district office/NRCS/Extension service; their staff will likely
have one that they can lend you or bring on a site visit.
•
Pruners or knife to clear soil surface of vegetation
•
Rubber mallet or mini sledge hammer
•
A 2 inch x 4 inch piece of sturdy board
•
Plastic wrap or plastic bag
•
Timer or stopwatch
•
15 oz (444 mL) of water x 2 (total 30 oz of water). (Either tap or irrigation water will work fine.
This amount will fill the infiltration ring to the height of 1 inch above soil surface.)
Activity - Water Infiltration
Instructions
1.
Draw a line on the infiltration ring to
indicate a depth of three inches.
2.
Clear the sampling area of plant
material and any debris. If the site is
covered with vegetation, trim it as
close to the soil surface as possible.
Don’t pull it out!
3.
Install the infiltration ring by covering it
with the piece of board and pounding
it in evenly with the mallet to the line
you drew at 3 inches. Two inches of
the ring will remain above the soil
surface.
4.
With the ring in place, use your finger
to gently firm the soil surface only
around the inside edges of the ring
to prevent extra seepage. Minimize
disturbance to the rest of the soil
surface inside the ring.
5.
Line the soil surface inside the ring
with a sheet of plastic wrap or the
plastic bag to completely cover the soil
and ring as shown in the image. This
prevents disturbance to the soil surface
when pouring in the water.
6.
Pour the 15 oz (444 mL) of water into
the ring lined with plastic wrap as
shown above.
7.
Remove the plastic wrap by gently
pulling it out, leaving the water in
the ring.
8.
Note the time. Record the amount of
time (in minutes) it takes for the water
to infiltrate the soil. Stop timing when
the surface is just glistening. If the
soil surface is uneven inside the ring,
count the time until half of the surface