Irrigation and Drainage Engineering

Question 1

— is the application of water to create a condition in the soil that is favorable
for plant growth. It provides the moisture needed by the crop that is not satisfied by
rainfall and refers to the controlled application of water fro agriculture through manmade systems

Answer 1

Irrigation

Question 2

—on the other hand, is the removal of excess water from the
soil with the same aim of creating conditions favorable for the growth of crops.

Answer 2

Drainage

Question 3

• the relative proportion of primary particles (sand, silt and clay) in the soil

Answer 3

Soil Texture

Question 4

• the arrangements of primary particles in the soil into units or peds

Answer 4

Soil Structure

Question 5

– the ratio of the void volume to the total soil volume (unitless)

Answer 5

Porosity (n)

Question 6

– the ratio of the weight of water to the dry
weight of the soil

Answer 6

on a dry weight basis (mcw)

Question 7

– the ratio of the
volume of water to the total soil volume

Answer 7

on a volume basis or volumetric moisture content (mcv)

Question 8

Densities (units:_______,_______ )

Answer 8

g/cm3
, kg/m3

Question 9

– the ratio of the dry weight of the soil to the total soil volume

Answer 9

Bulk density (ρB)

Question 10

• the ratio of the dry weight of the soil to the volume of the soil particles

Answer 10

Particle density (ρP)

Question 11

– ratio of the bulk density of the soil with the
density of water; it is the ratio of the weight of soil to the weight of water with
volume equal to the total soil volume

Answer 11

Apparent Specific Gravity (As)

Question 12

– ratio of the bulk density of the soil with the
density of water; it is the ratio of the weight of soil to the weight of water with
volume equal to the total soil volume

Answer 12

Apparent Specific Gravity (As)

Question 13

– ratio of the particle density of the soil with the
density of water; it is the ratio of the weight of soil to the weight of water with
volume equal to the volume of the soil particles alone

Answer 13

Real Specific Gravity (Rs)

Question 14

the equivalent depth of water in the soil at a given
condition

Answer 14

Depth of water : present in the soil (dw)

Question 15

to increase the moisture content from an initial value (mci) to a final
value (mcf)

Answer 15

Depth of water : needed (dwn)