Lecture 7: WATER MANAGEMENT Flashcards
an integrated process of timely application of the needed amount of water and the removal of excess water from the field to ensure optimum growth and crop productivity
WATER MANAGEMENT
LACK OF WATER CAUSES
- poor crop stand
- reduction in yield
- predisposes the plants to pests/diseases and nutri deficiency
EXCESS WATER CAUSES
- too much leaching, high acidity
- water-logged condition —> reduced root development
- predisposes plant to root-rotting pathogens
an effective and efficient irrigation program that addresses the following
- Appropriate timing and frequency of irrigation
- Adequate volume of water to apply
- Efficient method of application
FACTORS TO CONSIDER IN DEVELOPING A SUITABLE IRRIGATION PROGRAM
- soil
- climatic
- plant
FACTORS TO CONSIDER IN DEVELOPING A SUITABLE IRRIGATION PROGRAM
affects water holding capacity and water percolation
soil factors
FACTORS TO CONSIDER IN DEVELOPING A SUITABLE IRRIGATION PROGRAM
affects the rate of water losses through evap and transpi
includes temp, sunshine, humidity, wind movement
climatic factors
FACTORS TO CONSIDER IN DEVELOPING A SUITABLE IRRIGATION PROGRAM
includes rooting charac, rought tolerance, and growth stages
plant factors
methods of determining irrigation SCHEDULES:
- estimating avail soil moisture
- measure evapotranspi rates
- observe visual plant symptoms
- feel of the soil
- sand-cum-miniplot technique
methods of determining irrigation SCHEDULES:
- involves oven drying a sample of soil and compute soil moisture content
gravimetry
methods of determining irrigation SCHEDULES:
to measure the water potential which is inversely related to amount of available water
tensiometer
(methods of determining irrigation schedules)
visual symptoms u can observe
temporary wilting/leaf rolling
(methods of determining irrigation schedules)
visual symptoms u can observe
color of the foliage
METHODS OF IRRIGATION
- surface irrigation systems
a. furrow method
b. flooding method
c. basin method - sprinkler irrigation
- drip system
METHODS OF IRRIGATION
applied water seeps into side and bottom of
furrows to attain desired wetting
furrow method, under surface irrigation
METHODS OF IRRIGATION
water is applied by flooding the entire field
flooding method, under surface irrigation
METHODS OF IRRIGATION
trees are irrigated individually
basin method, under surface irrigation
METHODS OF IRRIGATION
highly pressurized water is delivered through network of pipes and comes out as fine droplets
sprinkler irrigation
METHODS OF IRRIGATION
water is applied through network of pipes and
comes out in the form of drips.
drip system
METHODS OF IRRIGATION
water is applied directly to the root zone in small
amount and continuously until desired wetting of
soil is attained
drip system
METHODS OF IRRIGATION
water is applied below the soil surface (through the underground system) and reaches plant root zone by capillary movement
sub-surface irrigation systems
SOURCES OF IRRIGATION
- river, stream, and lake
a. pumping
b. dam - small farm reservoir or water-impounding system (WIS)
- ground water
a. open well
b. tube well
SOURCES OF IRRIGATION
structure to collect rain and run-off water
water-impounding system (WIS)