*Agronomic Operation and Maintenance of Field Irrigation Systems DOI: http://dx.doi.org/10.5772/intechopen.84997*

*Irrigation - Water Productivity and Operation, Sustainability and Climate Change*

very low cost and in just a few training hours.

**4. Experiences**

In most situations, irrigation equipment malfunctions develop dynamically, leading to increasing expenditures for its solutions; thus, early detection of operational issues not only prevents negative impacts on crop yield and quality, but also in repairing costs. Comparing data on emitter discharge, end of lateral pressure, pressure at main valves, and water flow after filters, registered at least weekly, has proven to be an excellent method for early detection of irrigation equipment deficiencies.

Many irrigation systems are provided with operational registering options; however, the systematic analysis of this information is seldom included in the routine activities of field decision-making personnel. Available technologies enable the use of automatic cellphone alarms, triggered when the system operation deviates from specific preset discharge or pressure parameters. Data on actual irrigation system performance are seldom considered as a valuable crop production input; thus, a major educational effort is due to fully make use of these system capabilities, at a

We have selected data from just one field using our irrigation scheduling platform as an example, to fully present its many applications. The authors have implemented irrigation scheduling professional consulting since 1982 in more than 150 horticultural plantations in Chile, Mexico, Peru, and Argentina, on a cultivated area estimated at 5500 hectares. Concepts, parameters, coefficients, and computer programs, developed and published extensively in scientific and professional journals and presented at countless congresses, courses, and workshops, today serve as the basis for the correct use of irrigation systems in horticultural plantations, carried out also by many other professionals and technicians in different countries; selected irrigation scheduling publications by the senior author are available on Internet [41].

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**Table 1.**

*Vineyard data relevant for irrigation scheduling.*

Data for a 61.31-hectare vineyard, with two independent drip irrigation systems, three sectors each, planted in three different soils, with five different cultivars and two climate evaporative demand conditions are presented (**Table 1**).

**Figures 3** and **4** present data on irrigation for Cabernet sauvignon for plots 1 and 6 (different evaporative demand conditions, due to site topographic positions within the vineyard, as well as different soil hydrodynamic characteristics), for a time frame from November 15 to December 31, 2018; the platform enables the user to select data for any plot or plot combination, for any time span, from 1 day to the whole irrigation season. Daily comparisons between calculated ETp (red columns) and actual water depth applied (blue columns) are provided in graphic format, indicating a correct operation of the irrigation system throughout both dates, with the exception of December 25th, when no irrigation was performed, followed by two intensive irrigation days, to recover the difference. Water depths applied during the specified time span are also provided, comparing calculated ETp and water depth applied. This information is a helpful tool to decision-making for water recovery or withhold, aimed to keep a constant soil water content in the root zone.

**Figure 3.** *Irrigation scheduling for two Cabernet sauvignon plots, November 15–December 31, 2018.*

#### *Irrigation - Water Productivity and Operation, Sustainability and Climate Change*

#### **Figure 4.**

*Irrigation scheduling for Chardonnay and Merlot plots, November 15–December 31, 2018.*

A 15.1% difference on ETp between plots 1 and 6 accounts for climatic evaporative water differences between both plots. Three years before the implementation of the irrigation scheduling platform at this vineyard, both plots were irrigated with identical water depths and timings; as a result, significant differences in grape yield, average berry size, and wine organoleptic characteristics were obtained. These differences are almost nil for the last two vintages. Also, annual water and energy savings, due to the adoption of irrigation scheduling, account for 34.7%.

Similar data for plots 2 and 5 (cultivars Merlot and Chardonnay, respectively) are presented in **Figure 4**. Irrigation scheduling procedures follow a consistent concordance for daily calculated ET and actual water depth applied.

Between these dates, differences in water depth applied, as compared to calculated ETp, are 3.79% for Merlot and 0.21% for Chardonnay; however, the difference between both cultivars accounts for 340 m3 /hectare. Considering the whole season (data not shown), the calculated ETp difference between both cultivars is 1.216 m3 /hectare, equivalent to 19.7%, due to differences in the onset

**21**

**Figure 5.**

*Agronomic Operation and Maintenance of Field Irrigation Systems*

of each phenology dates, which significantly modify its respective Kc = f(t) functions. An irrigation scheduling strategy adequate for Merlot, applied into Chardonnay, will result in overirrigation, excessive canopy vigor, and poor wine organoleptic characteristics, as well as unnecessary water end energy costs in this

At the same vineyard, a different situation regarding irrigation scheduling was detected; **Figure 5** presents data for plots 3 and 4 (cultivars Syrah and Sauvignon blanc, respectively). Irrigation scheduling between December 1, 2018 and January 18, 2019 consisted on a daily 8 h unique irrigation event, regardless of actual ETp,

For the Syrah plot, on the average between these dates, no differences between

calculated ETp and actually applied water depth are detected, but if each day is considered separately, overirrigation took place during 20 days, and during 19 days, the plot was underirrigated. This time span includes the berry veraison

*Irrigation scheduling for Syrah and Sauvignon blanc plots, December 1, 2018–January 18, 2019.*

*DOI: http://dx.doi.org/10.5772/intechopen.84997*

with no irrigation taking place in December 25.

last plot.
