How many type of soil colloids?

A. 4
B. 2
C. 6
D. 5

N and P sprayed on the leaves at time of flowering results in:________?

A. Increase in fruit yield
B. Improve their protein
C. Increase fruit yeid & protein
D. None of these

Conversion of inorganic P to organic P is known as:_________?

A. Mineralization
B. Immobilization
C. Solubilization
D. Both a & c

Maximum fixation of K occurs:__________?

A. 1:1 clay mineral
B. 1:2 clay mineral
C. 2:1 clay mineral
D. 2:2 clay mineral

Azotobacter fixes atmospheric nitrogen in the soil by:__________?

A. Symbiotically
B. Non-symbiotically
C. Can fix a & b
D. None of these

What happens when an saline-alkaline soil is reached with water:

A. Ph decrease, ec increase
B. Ph & ec both increase
C. Ph increase & ec decrease
D. None of these

Irregular rock masses formed in the pre-existing cracks & crevices are:__________?

A. Sills
B. Dikes
C. Lacoliths
D. Batholiths

Immobile nutrient in soil is:_________?

A. P
B. N
C. Mg
D. None of the above

Ammonium sulfate fertilizer containing 21% N & 24% S, is best in top dressing in:_________?

A. Barley
B. Rice
C. Date palm
D. None of these

From the sources of plant nutrients availability in soil, which of the following statements are correct:

A. The plant absorbs carbon as carbondioxides directly from the atmosphere.
B. Water is the source of hydrogen
C. Air & water is the source of oxygen & the chief source of soil nitrogen is organic matter & when organic matter decomposes it gives ammonia.
D. All of the above