PERFORMANCE OF GRAPEVINES UNDER IRRIGATION SYSTEMS - Management, Performance, and Applications of Micro Irrigation Systems - page 257

Kadam and Sahane [45] studied the effect of NPK fertilizers and irrigation meth-
ods on the growth and quality of tomato cv. Dhanshree. Treatments comprised: of
75 and 100% recommended rate of fertilizers (RRF; 160:80:80; kg of NPK ha -1 ) in
briquette and nonbriquette forms through drip or surface irrigation. The drip irrigation
recorded signifi cantly higher total soluble solids, higher plant height and higher dry
matter content than surface irrigation. Treatment with NPK at 100% RRF resulted
in signifi cantly higher total soluble solids, higher plant height and higher dry matter
content compared to treatment with NPK at 75% RRF. The total yield was positively
correlated with yield contributing characters such as fruit weight and fruit number per
plant, and quality characters such as pH.
Abou-Salama et al. [3] used different irrigation methods to conserve water con-
sumption of sugarcane and to improve its water use effi ciency under Upper Egypt
conditions. They found that most of the juice quality parameters were not affected by
irrigation treatments. Azzazy et al. [8] used three irrigation systems (drip, developed
surface and traditional surface irrigation systems) to irrigate sweet sorghum. They
found that type of irrigation system signifi cantly affected forage yield. They added that
the highest sucrose and purity percentages were obtained under drip irrigation system.
20.1.5 EFFECT OF IRRIGATION SYSTEMS ON SOIL CHARACTERISTICS
20.1.5.1 SOIL MOISTURE CONTENT AND MOISTURE DISTRIBUTION
Drip or high frequency irrigation will often maintain low soil moisture suction (high
moisture content) in the effective root zone. Root growth can possibly augment the
influence of low soil moisture suction and maintain more favorable soil water intake
characteristics around the emitters. Gerard [30] mentioned that the wetting pattern
can be affected by the soil hydrological properties. The reduction in the ability of
soil to conduct water can be serious enough to create saturated soil conductions and
significant loss of effective roots. Earl and Jury [22] reported that moisture profiles for
the daily irrigation treatment under cropped conditions showed that downward water
movement is restricted to 60 cm depth when lateral movement occurs no further than
60 cm from the emitter. They observed water movement is observed up to 100 cm from
the emitter, while downward movement was restricted to about 75 cm. The rate of wa-
ter application in drip irrigation will affect the distribution of the applied chemicals. By
varying the parameters of the irrigation regime, different distribution may be obtained.
Levin et al. [55] studied the soil moisture distribution pattern when amount of water
was applied form a point source, but with different discharge rates. The continuous ir-
rigation treatment showed a loss due to deep percolation, of 26% of the total amount
of irrigation water below 60-cm depth after 12 h. The lateral distribution, in the same
treatment, showed that 80% of the water in the wetted volume was distributed up to 45
and 43 cm horizontally from the point source after 12 and 24 h, respectively. Only 12%
loss below 60 cm depth was found with pulsed irrigation, and 29 and 40 cm lateral
distribution after 12 and 24 h, respectively. Bacon and Davy [9] observed that irrigation
resulted in outward movement of water from the application point to a wetted zone in
the shape of a shallow dish. The size and duration of the wetted zone depended on the