64
What happens to the nitrogen and sulphur contents of vegetation when burning is used as a means of lans clearing? They
- A. are released by burning and lost as gases
- B. remain in ash as nitrates and sulphates
- C. raise the PH of an acid soil
- D. are released into the soil thus increasing the nutrients of the soil
- E. activate the soil microbes afetr burning
65
the nutrient content of soil may be influenced by the following except
- A. harrowing
- B. topography
- C. cropping
- D. fallowing
- E. grazing
66
The most important soil micro-organisms concerned with decay and nutrients-recycling are
- A. bacteria and fungi
- B. fungi and algea
- C. alga and actinomyces
- D. actinomyces and bacteria
- E. bacteria and algea