The answer depends on where the soil is, and also on how deep you dig into the square metre area.
None, since a square is a two dimensional shape.
1x1 meter is a square meter.
10,000 You could have found that by googling. ;)
OVER 2,700 KINDS OF EARTHWORMS CAN BE FOUND
200 square meter
1 square meter = 1,550 square inches.
1 square meter = 10.7639 square feet.
About 10.764 square feet per square meter.
1 square meter = 10.764 square feet.
1 square meter is 10.764 square feet.
Since a meter has 100 centimeters, a square meter has 10,000 square centimeters.
1 (square meter) = 10.76 square feet.