IRRIGATION: Artificial application of water to the land.
Proponents say, essential
for feeding ever increasing
Only 18% of worlds
cropped land is irrigated,
but produces 34% of food
CIVE 425 Class Notes for Unit I
All growing plants need water to satisfy evaporation taking place at their leaves in
response to the atmospheric energy (plant transpiration). The water must be stored in the soil
pores along with
Irrigation Water Management
at the Farm
Good water management at the farm must answer
following three inter-related questions:
1. How much water to apply?
2. When to apply? And,
3. How to apply water to the land?
1. How much water to apply? = f (SWC)
Unit I: Soil-Water Relations
Expressing soil moisture; its determination
Water retention in soil pores
Soil-water holding capacity
Water availability for plant growth
Water movement and uptake by plants.
Forces Acting on
Water is bi-polar mole
Unit 1: Soil-Water Relationships
Week 1: Understanding soil
Soil as a medium for plant growth,
Some important physical properties,
Soil classification for plant growth.
Week 2-3: Soil-water relations
Water retention, soil-water holding capac
Unit 2: Crop-Water Requirements
We will learn following topics:
1. Soil-water-plant system: water flow thru the system
2. Why plants need to consume water? Crop
consumptive use or crop water requirements (CWR)
3. How to measure and forecast CWR?
This equation is in based of energy balance and
Consequently, it requires accurate weather data
(presence of weather station data).
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