lesson 6

Question 1

involves the application of the right amount of water at the right time

Answer 1

Irrigation

Question 2

Importance of water

Answer 2

● More than 80% of the weight of plants is water.
● Water plays an important role in photosynthesis.
● A lot of nutrients are absorbed by plants with water.
● Water must be provided in the right amount and at the right time.

Question 3

What are the factors to consider in irrigation?

Answer 3

1. Climatic factors
2. Plant factors
3. Soil factors

Question 4

Water transpired from the leaves of plants, evaporated from other plant, soil and water
surfaces.

Answer 4

Evapotranspiration

Question 5

consumptive use of water

Answer 5

Evapotranspiration

Question 6

What is Evapotranspiration highly affected by?

Answer 6

climatic factors?

Question 7

rainwater that penetrates the soil surface and is retained in the root zone

Answer 7

Effective Rainfall

Question 8

What kind of rooted crops are more tolerant to low moisture stress?

Answer 8

deeply rooted crops

Question 9

Normal root development is greatly affected by what?

Answer 9

amount of moisture in the soil

Question 10

What do plants require in their root zone?

Answer 10

enough moisture

Question 11

When is water needed?

Answer 11

germination

Question 12

When does the water requirement increase and reach it’s peak

Answer 12

flowering and early ripening stage

Question 13

When does water demand decrease?

Answer 13

maturation

Question 15

the amount of water that penetrates the soil surface over a period of time

Answer 15

Infiltration rate

Question 16

the amount of moisture retained in the soil for possible crop use

Answer 16

Water holding capacity

Question 17

most suitable soil texture to use

Answer 17

loam

Question 18

Which soil has medium infiltration rate?

Answer 18

silt

Question 19

Which soil has medium water holding capacity?

Answer 19

silt

Question 20

Which soil has high infiltration rate?

Answer 20

sand

Question 21

Which soil has low water holding capacity?

Answer 21

sand

Question 22

What soil has low infiltration rate?

Answer 22

clay

Question 23

What soil has high water holding capacity?

Answer 23

Clay

Question 24

What affects the infiltration rate and water holding capacity due to what?

Answer 24

amount of organic matter

ability to improve aggregation and its affinity to hold water

Question 25

What are practical ways to determine when to irrigate?

Answer 25

1. Temporary wilting 2. Color of wiltage 3. Rate of growth 4. Feel method 5. Use of indicator plots

Question 26

Conveys water to the field by allowing it to run along the surface of the land using irrigation canals or ditches by gravity

Answer 26

surface or gravity methods

Question 27

Water is allowed to flow along small channels as it moves down the slope of the field

Answer 27

furrow irrigation

Question 28

Where is furrow irrigation applicable?

Answer 28

to plants grown in rows along the ridges in areas with gentle slope

Question 29

How much water does furrow irrigation need?

Answer 29

a large amount

Question 30

Applicable in areas where water is abundant and inexpensive.

Answer 30

Flooding

Question 31

What is flooding commonly used for?

Answer 31

wetland rice

Question 32

What must the field be surrounded by when using the flooding method?

Answer 32

leaves

Question 33

What area should not be flooded for a longtime to prevent waterlogging?

Answer 33

dryland crps

Question 34

Water is applied above the plant canopy simulating rain

Answer 34

OVERHEAD IRRIGATION

Question 35

Simplest method, water is carried and applied manually in watering cans

Answer 35

Use of watering cans

Question 36

Limited to small areas with an accessible source of water

Answer 36

Use of watering cans

Question 37

Applicable in areas with piped water distribution system with sufficient pressure.

Answer 37

Use of hose pipes

Question 39

Water is applied in the form of spray similar to rain.

Answer 39

Use of sprinklers

Question 40

Water is directed to the base of the plant using pipelines either laid on the soil or buried underneath

Answer 40

Drip irrigation

Question 41

Where is drip irrigation highly applicable?

Answer 41

areas with scare water supply

Question 42

Considered an efficient method in terms of water use

Answer 42

Drip irrigation

Question 43

How many liters of water does the rice crop needs to produce a kg of rice?

Answer 43

1300-1500 liters

Question 44

How many liters of rain water does under ideal conditions need per cropping/

Answer 44

400-2000 mm

Question 45

How many percent does rice production receive of total world irrigation water?

Answer 45

34-43 %

Question 46

How many percent does production receive of freshwater resources?

Answer 46

24-30%

Question 47

Involves medium to deep flooding

Answer 47

Continuous flooding with standing water

Question 48

How is water level regulated with Continuous flooding with standing water?

Answer 48

adjusted regularly to the desired depth

Question 49

Involves shallow, medium, or deep flooding

Answer 49

Continuous flooding with flowing water

Question 50

How is water level regulated with Continuous flooding with standing water?

Answer 50

Water level is regulated by the height of the spillways

Question 51

How is intermittent irrigation done?

Answer 51

Flooding is done rapidly for 4-7 days then water is completely drained until the next irrigation period

Question 52

Involves impounding rainwater water in the field for the entire cropping period

Answer 52

Rainfed water management

Question 53

The combined application of water and nutrients to a crop

Answer 53

Fertigation Systems

Question 54

A mix of fertilizer application and irrigation

Answer 54

Fertigation Systems

Question 55

Where is fertigation systems most common?

Answer 55

cash-crop

Question 56

What are the advantages of fertigation systems

Answer 56

- Better nutrients absorption by plants - More efficient use of fertilizer, chemicals, and water - Less leaching of chemicals into the water supply - Increases the root mass's leading to a better ability to trap and hold water - Application of nutrients can be regulated at the time and rate necessary - Less chance of roots contracting soil-borne diseases - Reduced soil erosion

Question 57

What are the methods of soil conservation?

Answer 57

● Zero or minimum tillage ● Cover cropping ● Mulching ● Enriching the soil's organic matter (composting, green manuring)