Teaching Organic Farming and Gardening

Soil Physical Properties

38 | Unit 2.1

10. which of the following influence the available
    water-holding capacity of the soil?

a. Texture

b. Structure

c. Organic matter

d. Salts

e. a, b and c

f. a, b, c, and d

g. a, c and d

assessMent

1. why are the “empty” places in the soil so
   important?


2. Clay contributes many good characteristics
   to soil, but if there is too much it can cause
   problems. what are some of the negative
   effects of too much clay in the soil and how
   can these effects be overcome?


3. what are some of the negative effects of too
   much sand in the soil and how can these
   effects be overcome?
   4. Use a soil texture triangle to calculate the
   soil texture for the following combinations of
   sand, silt and clay:
   a. 25% sand, 30% silt, 45% clay

b. 40% sand, 30% silt, 30% clay

c. 60% sand, 10% silt, 30% clay

d. 70% sand, 12% silt, 18% clay

e. 90% sand, 5% silt, 5% clay

f. 80% sand, 15% silt, 5% clay

g. 10% sand, 85% silt, 5% clay

h. 5% sand, 75% silt, 20% clay

i. 40% sand, 40% silt, 20% clay

j. 55% sand, 5% silt, 40% clay

k. 10% sand, 60% silt, 40% clay

l. 5% sand, 45% silt, 50% clay

5. what surface structure is most desirable?
   what can you do to help develop this
   structure and maintain it?

Assessment Questions