Agriculture Reference
In-Depth Information
20.3
RESULTS AND DISCUSSION
20.3.1
EFFECT OF IRRIGATION SYSTEMS ON SOIL CHARACTERISTICS
20.3.1.1 WATER INTAKE
The Figs. 4 to 6 indicate the effects of drip irrigation system (DIS), low head
bubbler irrigation system (LHBIS) and gated pipe irrigation system (GPIS) on water
intake rate (IR) and accumulative intake rate (ACC-IR) in cm/h. In each of the three
irrigation systems, IR decreased, whereas the (ACC-IR) increased with time. This
general trend can be attributed to one or more of the following reasons: 1) occurrence
of water column above the soil surface during measuring process may have hindered
escaping the trapped air bubbles, 2) an inevitable decrease in matric gradient constitut-
ing one of the main forces drowning water into the soil which usually occurs as water
intake process proceeds, 3) large easily accessible pores in the soil may have been
fi lled with irrigation water before the smaller ones, 4) breakdown some soil aggregates
due solubility and relaxation of some bonds and increasing trapped air pressure within
the aggregates.
FIGURE 4
Water intake into soil in drip irrigation system.
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