Page 53 - soil-plant-water relationship and water requirement

SOIL-PLANT-WATER RELATIONSHIP AND WATER REQUIREMENT

iii. Hours of day-light also increase evaporation.

iv. Water requirement of a plant varies for different stages of growth during
the crop season.

v. Evaporation and transpiration depends upon humidity of a locality

vi. Evaporation of water is greatly affected by movement of wind. Hot, dry
winds increase evaporation.

vii. The growing season influences seasonal use of water by plants.

viii. Quality of water used has also minor effect on the consumptive use.

ix. Soil characteristics like fertility, permeability, pH value etc., also affect the
consumptive use to some extent.

5.5.1 Crop Water Requirement and Irrigation Water Requirement Relationship

Crop Water Requirement (CWR) and Irrigation Water Requirement (IWR) can
be best described as

Crop Water Requirement depend on weather and crop

CWR = f (weather, crop)

Irrigation Water Requirement depends on weather, crop, soil, rainfall,
irrigation method and depth to water table

IWR = f (weather, crop, soil, rainfall, irrigation method, depth to
water-table)
So, Supply of Irrigation Water Requirement must be more than Crop Water
Requirement

CWR < IWR

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