lesson 6 Flashcards
sana pasado yesss amen
involves the application of the right amount of water at the right time
Irrigation
Importance of water
● 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.
What are the factors to consider in irrigation?
- Climatic factors
- Plant factors
- Soil factors
Water transpired from the leaves of plants, evaporated from other plant, soil and water
surfaces.
Evapotranspiration
consumptive use of water
Evapotranspiration
What is Evapotranspiration highly affected by?
climatic factors?
rainwater that penetrates the soil surface and is retained in the root zone
Effective Rainfall
What kind of rooted crops are more tolerant to low moisture stress?
deeply rooted crops
Normal root development is greatly affected by what?
amount of moisture in the soil
What do plants require in their root zone?
enough moisture
When is water needed?
germination
When does the water requirement increase and reach it’s peak
flowering and early ripening stage
When does water demand decrease?
maturation
the amount of water that penetrates the soil surface over a period of time
Infiltration rate
the amount of moisture retained in the soil for possible crop use
Water holding capacity
most suitable soil texture to use
loam
Which soil has medium infiltration rate?
silt
Which soil has medium water holding capacity?
silt
Which soil has high infiltration rate?
sand
Which soil has low water holding capacity?
sand
What soil has low infiltration rate?
clay
What soil has high water holding capacity?
Clay
What affects the infiltration rate and water holding capacity due to what?
amount of organic matter
ability to improve aggregation and its affinity to hold water
What are practical ways to determine when to irrigate?
- Temporary wilting
- Color of wiltage
- Rate of growth
- Feel method
- Use of indicator plots
Conveys water to the field by allowing it to run along the surface of the land using irrigation canals or ditches by gravity
surface or gravity methods
Water is allowed to flow along small channels as it moves down the slope of the field
furrow irrigation
Where is furrow irrigation applicable?
to plants grown in rows along the ridges in areas with gentle slope
How much water does furrow irrigation need?
a large amount
Applicable in areas where water is abundant and inexpensive.
Flooding
What is flooding commonly used for?
wetland rice
What must the field be surrounded by when using the flooding method?
leaves
What area should not be flooded for a longtime to prevent waterlogging?
dryland crps
Water is applied above the plant canopy simulating rain
OVERHEAD IRRIGATION
Simplest method, water is carried and applied manually in watering cans
Use of watering cans
Limited to small areas with an accessible source of water
Use of watering cans
Applicable in areas with piped water distribution system with sufficient pressure.
Use of hose pipes
Water is applied in the form of spray similar to rain.
Use of sprinklers
Water is directed to the base of the plant using pipelines either laid on the soil or buried
underneath
Drip irrigation
Where is drip irrigation highly applicable?
areas with scare water supply
Considered an efficient method in terms of water use
Drip irrigation
How many liters of water does the rice crop needs to produce a kg of rice?
1300-1500 liters
How many liters of rain water does under ideal conditions need per cropping/
400-2000 mm
How many percent does rice production receive of total world irrigation water?
34-43 %
How many percent does production receive of freshwater resources?
24-30%
Involves medium to deep flooding
Continuous flooding with standing water
How is water level regulated with Continuous flooding with standing water?
adjusted regularly to the desired depth
Involves shallow, medium, or deep flooding
Continuous flooding with flowing water
How is water level regulated with Continuous flooding with standing water?
Water level is regulated by the height of the spillways
How is intermittent irrigation done?
Flooding is done rapidly for 4-7 days then water is completely drained until the next irrigation period
Involves impounding rainwater water in the field for the entire cropping period
Rainfed water management
The combined application of water and nutrients to a crop
Fertigation Systems
A mix of fertilizer application and irrigation
Fertigation Systems
Where is fertigation systems most common?
cash-crop
What are the advantages of fertigation systems
- 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
What are the methods of soil conservation?
● Zero or minimum tillage
● Cover cropping
● Mulching
● Enriching the soil’s organic matter (composting, green manuring)
