Azotobacter fixes atmospheric nitrogen in the soil by:__________?

Related Mcqs:

1. Nitrogen & sulphur dioxide liberate from motor vehicles & industries. Nitrogen & Sulphur gases dissolve in the water vapour of atmosphere & form nitric & sulphuric acid. This rain water falls on soil as__________ & contaminates soil also:

   A. Acid rain
   B. Neutral rain
   C. Both A & B
   D. None of the above

   Submitted by: Shafiq Rehman

2. Any material such as straw, sawdust, leaves, plastic films, & loose soil that is spread upon the surface of the soil to protect the soil & plant roots from the effects of raindrops, soil crusting, freezing or evaporation:

   A. Mull
   B. Mulch
   C. Mycorrhizae
   D. Muck

   Submitted by: Shafiq Rehman

3. Soil additive which stabilizes the soil, improves resistance to erosion, increases to permeability to air & water, improves texture, eases cultivation or otherwise improves soil quality:

   A. Soil amendment
   B. Soil conditioner
   C. Both a & b
   D. None of the above

   Submitted by: Shafiq Rehman

4. Flow of nitrogen in soil due to:_________?

   A. Diffusion
   B. Interception
   C. Mass flow
   D. None of the above

   Submitted by: Shafiq Rehman

5. Preferable form of nitrogen for rice under submerged soil conditions is ____________?

   A. NH4
   B. NO3
   C. NO2
   D. All of these

   Submitted by: Muhammad Rehan

6. Soil erosion is __________ of soil from one place ti another place by natural agencies (wind & water):

   A. Detachement of soil
   B. Transportation
   C. both A & B
   D. None of these

   Submitted by: Shafiq Rehman

7. A soil is classified as sodic soil when______________________?

   A. EC is 8.5
   C. SAR is >13
   D. All the above

8. Addition of sodium hexametaphosphate in soil for determination of soil texture causes__________________?

   A. Agregation of soil particles
   B. Cementing of soil particles
   C. Dispersion of soil particles
   D. All the above

9. Organic P content in soil, by ignition method is estimated by igniting the soil at ____________________?

   A. 250ºC
   B. 1000ºC
   C. 550ºC
   D. 1250ºC

10. The major soil fertility problems in Pakistani soils deficiencies of N, P and Zn. Deficiencies K, Fe, and B also occur in specific crop genotypes or soil types, while deficiencies of S, Cu, and Mn are negligible. however, the common nutrient deficiencies are_________________: and some micronutrients including Mo?

    A. N, P, K
    B. Ca, Mg, S
    C. both A & B
    D. The above statement is wrong

    Submitted by: Shafiq Rehman