Page 52 - soil-plant-water relationship and water requirement

SOIL-PLANT-WATER RELATIONSHIP AND WATER REQUIREMENT

(Inflow) - (Outflow) = (Change in Storage)

( I + P + C) - (ET + DP + R) = (S)

S = P + I + C - ET - DP - R

Figure 5.4-1: Inflow and Outflow Proses Diagram

5.5 IRRIGATION WATER REQUIREMENT AND SCHEDULE

The water management thus involves perfect knowledge of soil- water-crop
relationship under any given climatic condition as well as various engineering aspects
of irrigation from the storage down to the fields.

The estimation of irrigation water requirement of a crop assumes a pivotal role in the
scientific water management technique. Many factors affect the amount of irrigation
water required by a plant.

The effect of these factors vary from place-to-place and also fluctuate from time-to-
time at the same place.

The important factors which influence the irrigation water requirement are the
following:

i. Amount and rate of precipitation during a crop season.

ii. Temperature variations in any particular locality greatly affect the rate of
consumptive use.

43