A. Reduced soil disturbance through no-till or minimum till
B. Residue return to keep at least 30% of soil covered
C. Crop rotations for better utilization of available water & nutrients
D. all of the above
Soil Science
The availability of essential nutrients from soil to the plants is controlled by the …….. properties of soil:
A. Physical
B. chemical
C. Biological
D. both A & B
Which of the following is wrong?
A. Sandy soils have higher sand percentage with more water holding capacity
B. The relative percentage of sand, silt, clay is soil texture.
C. Soil texture influences behavior of soil.
D. The arrangement of soil aggregates is called soil structure.
Which of the following is not the soil order prevail in Pakistan?
A. Aridisols
B. Alfisols
C. Mollisols
D. None of the above
The internal & external surfaces of soil colloids are positively and or negatively charged. Mostly ………… is dominant:
A. Positive
B. Negative
C. Zero
D. All of the above
Each layer of phyllosilicates is composed of two types of sheets:
A. Tetrahedral sheet
B. Triple octahedral sheet
C. Octahedral sheet
D. Both A & C
Soil Organic Matter (SOM) which consists of about ……. % organic carbon plays a vital role by providing macro & micro nutrients:
A. 72 %
B. 58%
C. 62 %
D. Al of the above
A mineral horizon that is either too thin, too light in colour, too low in organic matter:
A. Umbric epipedon
B. Melanic epipedon
C. Mollic epipedon
D. Ochric epipedon
Which of the following nutrient elements are regarded as energy exchangers:
A. Hydrogen
B. Oxygen
C. Both A & B
D. None of these
Which element is known as chemical police man of plant?
A. Magnesium
B. Phosphorus
C. Potassium
D. All of the above