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1. Soils NR 200
2. Unit 1 The Soils
Around Us
3. What is soil? Dictionary – The unconsolidated material that occupies the earth’s surface and supports plant life.
Or perhaps: The link between the living and non-living. (The non-living supporting the living)
5. I. Functions of Soil in our Human World A. Medium for plant growth
B. Important component of the hydrological system
C. Mother nature’s way of recycling organisms
D. A sphere for living organisms ie macro and micro organisms
E. Supporting foundations of our human made structures
6. II. Four major components of soil.
7. Minerals: 45%
8. Air 20-30% 1) the roots need O2 for respiration
2) organisms need O2 as well
9. Soil Solution: water with dissolved minerals held in the soil particles.20-30%
10. Organic matter 1) From once living organisms
2) Decaying and making their minerals available again
3) Improves water holding capacity
4) Humus is the longer lasting material that is responsible for this water holding ability, colloidal.
11. III. Plant Requirements for Soil or What the soil needs to provide the plant to allow it to grow successfully
12. A. Anchorage 1) Needed to allow the plant to have as many leaves positioned to accept sunlight
2) Keep plant in place to receive water and minerals
13. B. Oxygen 1) Needed to allow for respiration
2) Needed for microorganisms to flourish
14. C. Water 1) Almost all the water the plants need
comes from the soil
2) Also important for the microbial
action in the soil
3) Important for nutrient absorption
18. D. Temperature moderation 1) The ability of the soil to insulate itself from the extreme hot and cold of the air above it.
2) Allows the roots to grow and an environment favorable to microorganisms
19. E. Nutrients: 16 essential for plant growth 1) Only C,H and O are taken in by the plant from the atmosphere the other 13 are from the soil.N,P,K, Ca, Mg, S, Fe, Mn, Zn, Cu, B, Mo, and Cl?
A few to watch Ni, Co, Na and Si?
2) Root hairs are the plant structure responsible for bring in the nutrients and water.
22. 3) The plant obtains these minerals by:
a) Root interception - that is the root
grows into a new area and captures
the ionic solution.
24. F. Free From Harmful Organisms
26. O- Organic layer i - undecomposed organic material
a – organic material highly decomposed
27. A- Topsoil:The Most Productive Soil 1) Best for nutrient holding, water capacity, micro-organisms
2) The most important soil profile for plant life
3) p – plowed or other cultivated disturbance (man made)
28. E – An area where the greatest eluvation (removal of clay, iron and OM) occurs, resistant materials such as quartz, sand and silts remain usually light in color.
29. B – Sub Soil or Zone of Accumulation, Illuviation - Usual Location of Hardpan m - cemented zone usually silicates or calcium
g - strong gleying
31. C – Parent material but broken down but not subject to the soil forming properties as the above solum (A&B) and not massive in structure as R
32. Soil Profile
34. V. Soil texture is the amount of sand, silt and clay in the soil.
35. VI. Soil structure is ……….the way these smaller aggregates form larger particles.
37. With proper management and care our soils can produce a healthy bountiful harvest
38. Uses of Soil 1) Agriculture
2) Non-Agriculture
a) Recreation
b) Foundations
c) Waste disposal
d) building materials
3) Land use of the future????