Theory question 103
Soil Properties(a) Define the term soil
(b)(i) List the four components of soil (ii) State the percentage of each component by volume
(c) Describe the process involved in making compost using the pit method under the following headings: (i) materials; (ii) preparation; (iii) storage
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(a) Soil is the loose, weathered upper layer of the earth's crust in which plants grow, made up of mineral matter, organic matter, water and air
(b) Mineral matter about 45%; organic matter about 5%; water about 25%; air about 25%
(c)(i) Materials: plant residues (grass, leaves, crop residues), animal dung/urine, kitchen waste, wood ash/lime, topsoil, water, poles or sticks
(ii) Preparation: dig a pit (e.g. 1–2 m wide, about 1 m deep) in a shady well-drained place; put coarse materials at the bottom; add layers of plant material, then dung, then a sprinkle of ash/lime and topsoil; water each layer; repeat to the top; insert a stick to check heat; turn the heap every few weeks; compost is ready in about 2–3 months when dark and crumbly
(iii) Storage: keep covered in a shaded place, protected from sun and rain to prevent loss of nutrients by drying and leaching; use soon
Give the four components with approximate volumes.