Soil Science

Clay and humus particles are referred to as colloids and are less than 0.002mm. Due to their small size, colloids have ________________ surface area which provides surface for adsorption, catalysis, precipitation and microbial colonization:

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Clay and humus particles are referred to as colloids and are less than 0.002mm. Due to their small size, colloids have ________________ surface area which provides surface for adsorption, catalysis, precipitation and microbial colonization:

A. Extremely low
B. Extremely high
C. Very little
D. None of these

Soil samples are collected:

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Soil samples are collected:

A. From the field with immediate application of fertilizer or amendments
B. Field with upper white layer of salts
C. Boundaries of the field
D. None of these

_________ erosion is the removal of a thin layer of soil by water acting over the whole surface. This type of erosion damaged very fertile lands located on slopes, some of which have been eroded to a depth of about 15 cm.

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_________ erosion is the removal of a thin layer of soil by water acting over the whole surface. This type of erosion damaged very fertile lands located on slopes, some of which have been eroded to a depth of about 15 cm.

A. Rain splash rill erosion
B. Stream bank erosion
C. Sheet erosion
D. Gully erosion

In Pakistan there is general deficiency of rainfall. It varies from 125 mm annually in upper Sindh to about 900 mm in the sub-mountainous of northern Pakistan. In Balochistan the mean annual rainfall is about 200 mm, diminishing to ________ mm in the desert of Kharan:

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In Pakistan there is general deficiency of rainfall. It varies from 125 mm annually in upper Sindh to about 900 mm in the sub-mountainous of northern Pakistan. In Balochistan the mean annual rainfall is about 200 mm, diminishing to ________ mm in the desert of Kharan:

A. 100 mm
B. >70 mm
C. <50 mm
D. None of these