The organic matter, generally 0.5 – 0.8% to about 75 – 100 cm depth, drops to about 0.3% at ______.

Related Mcqs:

1. Which of the following horizons has the maximum amount of organic matter?

   A. Horizons A2 and B
   B. Horizon B only
   C. Horizon A1
   D. Horizons B and C

2. When the substratum has ample of organic matter and there are many deterivore participating in the process, the succession is called:

   A. Allogenic
   B. Retrogressive
   C. Heterotrophic
   D. Induced

3. Sources of organic matter are:

   A. Primary
   B. Secondary
   C. Both (a) & (b)
   D. None of these

4. The major effects of soil organic matter are:

   A. Soil depth
   B. Climatic situation
   C. Both (a) & (b)
   D. None of these

5. Soil organic matter includes:

   A. The partially decayed
   B. Resynthesized plant
   C. Animal residues
   D. All of the above

6. Pakistan has a total livestock population of about 100 million heads, composed primarily of ______:

   A. Goats
   B. Sheep
   C. Cattle
   D. Buffaloes
   E. All of the above

7. A windbreak with 50% crown density is more effective than one of either 100% or of ______ density:

   A. 15%
   B. 20%
   C. 25%
   D. 30%

8. These are generally, but not always, developed above the birch zone and in patches, sometimes extensive, within it, probably conditioned by edaphic and biotic factors, in Kashmir, Gilgit, Chitral and Hazara. This type ascends normally to ______ or more above the sub-alpine forests and climate must be similar but more severe than in sub-alpine forests:

   A. 140 m
   B. 150 m
   C. 160 m
   D. 170 m

9. A lake with an inflow of domestic sewage rich in organic waste may result in:

   A. Drying of the lake very soon due to algal bloom
   B. An increased production of fish due to lot of nutrients
   C. Increased population of aquatic food web organisms
   D. Death of fish due to lack of oxygen

10. Thermal insulation, leading to greater deposition of dew. In addition organic mulches also contribute to:

    A. Enhanced humification and microbial activity leading to higher nutrient availability
    B. Improvement of soil structure, by incorporation of plant residues and by encouraging soil fauna.
    C. Mulching is of profound importance in dry regions
    D. Even in more humid climates it may have very beneficial effects with certain species, e.g., the poplar
    E. All of the above