Agriculture Reference
In-Depth Information
Advantages and Disadvantages of Drip Irrigation in Vineyards
Table 6.5
Advantages
Disadvantages
Water applied to individual vines can be
Blocking of emitters (0.5-1.2 mm orifices)
closely controlled; particularly suited to
due to suspended particles in the water,
RDI and PRD . With frequent application,
chemical precipitates, or microbial
soil water content (and
m ) in the root
growths. Water must be filtered, and
zone is maintained in a narrow range.
wastewater may need to be chlorinated.
Root invasion can be a problem for SDI .
Very low losses by evaporation and runoff
Salt accumulates at the edge of the wetted
(especially for SDI ), because area of wet
zone, especially if there is insufficient
soil is small and rates of application are
winter rain to leach these salts out of the
low. No foliar salt uptake as with overhead
root zone (more of a problem with low-
sprinklers.
quality irrigation water)
Very low drainage losses (and hence loss
Rodents, other mammals, and birds can
of nutrients or potential contaminants) if
damage the soft, flexible pipes when they
RDI is practiced.
are seeking water (not a problem for SDI ).
Targeted fertilizer application by
Less effective microclimate control than with
fertigation ; see chapter 5.
overhead sprinklers, which can be used to
avoid frost damage to vines at critical times,
such as bud burst, flowering, and fruit set.
Allows irrigation water of higher salinity
More expensive than overhead sprinklers.
to be used, compared with overhead
sprinkler or flood systems (where
irrigation is less frequent and the soil dries
between applications).
Wastewater can be used because there is
no chance of pathogens contaminating
foliage or fruit; see chapter 7.
Restricted weed growth, especially with
SDI , and no constraints on access because
of wet soil.
Effective on marginal soils and in difficult
topography (stony soils, steep slopes).
Low operating pressures (100-200 kPa)
mean lower energy costs for pumping
compared to overhead sprinklers.
Macroirrigation Systems
A network of overhead sprinklers wets all the soil surface, so excess water may be
applied in parts of the vineyard, which can lead to drainage losses. Losses by evap-
oration as the water is being applied can be high, and salts in the water can be
absorbed into the leaves via stomata, which is undesirable. Access to the vines is
restricted during, and for a time after irrigation. However, overhead sprinklers can
be used to raise the humidity of the air when a frost is likely: the high specific
heat capacity of water (section 3.5.2), and its high latent heat, help to prevent the
air temperature from falling below 0°C. Overhead sprinklers need not be fixed,
6.6.2
 
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