**3. Irrigation system maintenance, improvements, and spare parts replacement**

Routine irrigation equipment maintenance protocols are needed for sustainable achievement of the potential economic return of investments, by ensuring the timely, complete, uniform, and efficient water supply to the crop. In most field systems, regardless its size or irrigated crop value, maintenance protocols are seldom implemented in full, and generally are only addressed when major system failures are detected, affecting crop yield and fruit quality, due to water supply interruptions during the repairing time span [39]. Maintenance is an important, though often overlooked, operation to extend not only the trouble-free life of the system itself but to maximize returns on investment. Preventative rather than corrective maintenance is more economical and less traumatic. The implementation of a maintenance program for drip irrigation systems will keep the system operating at peak performance and increase the system's work life expectancy. The best way to determine if the maintenance program implemented is effective is to constantly monitor and record the flow rate and pressures in the system [3].

#### **3.1 Winter maintenance protocol**

It is one of the most important maintenance activities, to be performed during the postharvest winter period; if the total winter rainfall is below the average value of the area, it is necessary to operate the irrigation system at the beginning of spring, before crop budbreak (permanent orchards) or emergence (annual crops), when the spring root activity is initiated, in order to start the irrigation season with a soil water depth equivalent to its field capacity.

**17**

*Agronomic Operation and Maintenance of Field Irrigation Systems*

boards, filter back-washing boards, and all the fertilizer preparation and injection systems. In the field, mains, submains, manifolds, and irrigation laterals are washed to evacuate any sediment that may have precipitated and the emitters are revised to change those that are in poor condition. In persistent fruit orchards species, it may be necessary to continue watering in the winter, so this maintenance operation is

The goal of the winter maintenance is to ensure that at the start of the new irrigation season, all equipment components are in optimal operative condition. The cost of this winter maintenance operation, including the cost of some spare parts that need to be replaced, plus the replacement cost of filtering media (quartz sand, meshes, and filter disks), generally represents 2–3% of the original irrigation equipment investment. Once the irrigation equipment has been reassembled after this winter maintenance, it is necessary to calibrate its operation, in terms of the emitters' discharge uniformity, operating pressures across the whole hydraulic

Throughout the irrigation season, implementing a daily maintenance protocol for the irrigation equipment components is required, basically consisting of the analysis of the registered operation information provided by volume totalizers, flow measurements, and operation times for each irrigated sector, for early detection of

The goal is to always keep within a range of variation that does not exceed 5% of the pressure and discharge values established in the original design of the equipment. If any of these two parameters deviate above or below this range, at any point of the irrigation network, it is necessary to find the failure point or section and repair it immediately, to maintain the correct supply of water to the crop.

The most frequent problems to find during the irrigation season are partial emitter clogging, irrigation hydraulic valve elasticity reductions, leading to incomplete opening or closing, breakages and leaks in the water distribution pipes, filters' inadequate cleaning, malfunctioning of electrically operated pilot valves, pump efficiency reductions, and mechanical damage of laterals due to field operations

At least once every 2 weeks, the following maintenance procedure is

1.Flush all the laterals by opening end plug 1–5 in a series; then close them 1–5 in the same sequence allowing flushing for 3 min until clean water starts flowing.

2.Flush each submain at the end of every section (shift) till dirt-free clear water

4.Take out the element of screen/disc filter and clean it thoroughly. Open the lid of sand (media) filter, allow the water to come out through it, for thoroughly separating accumulated foreign material with media (sand) for recharging its

3.Check inlet and outlet filter pressures. Remove slurry from sand filtration

media with back flush at every 5 h; flush screen/disc filter.

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

performed after a significant rain.

network, and elimination of water leaks [40].

(labor, animal, or machinery) or rodent damage.

eventual anomalies in its operation.

**3.3 Periodic maintenance**

starts flowing.

filtering capacity.

mandatory:

**3.2 Irrigation equipment routine operation maintenance**

Pumps, filters, and valves are dismantled in the control room, as well as the entire electrical installation, including power boards, irrigation programming

## *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*

following irrigation seasons (see Section 2.2.2) [35].

**replacement**

availability condition; these data are obtained by using soil water content probes, providing either real-time or periodic measurements with portable soil probes. This platform feature is an independent checking for the balance between calculated ETc and actual depth water applied, enabling to automatically correct eventual errors in the calculated ETc. If the calculated ETc value is lower than the actual ETc, platform recommendations will determine underirrigation and a gradual reduction in the soil water content, while if calculated ETc > actual ETc, overirrigation will determine a gradual increment in the soil water content. Soil water content increments or reductions over 5% between consecutive measurements trigger automatic modifications on Kc values for the next 5 days and thus, the process is self-adjusted. All Kc adjustments are kept in an historical file, to be used as platform input data for the

Adjustment of Kc daily values related to soil water dynamics, as affected by the balance between calculated ETc and actual irrigation water depth applied, represents an automatic fine-tune procedure on irrigation scheduling, aimed to keep a constant crop water availability condition, simultaneously considering atmospheric evaporative demand, crop IAF evolution, and actual irrigation timing and water depth applied; this adjustment is seldom found in most irrigation scheduling models available in the market. We have assumed that ETp data retrieved from weather stations and actual irrigation water application are trustworthy, since modern irrigation equipment provides automatic digital operation registering options (date, time, water volume applied on each field irrigated section), including data transmission by radio frequency or through the Internet, thus reducing human intervention on data handling.

**3. Irrigation system maintenance, improvements, and spare parts** 

monitor and record the flow rate and pressures in the system [3].

**3.1 Winter maintenance protocol**

a soil water depth equivalent to its field capacity.

Routine irrigation equipment maintenance protocols are needed for sustainable achievement of the potential economic return of investments, by ensuring the timely, complete, uniform, and efficient water supply to the crop. In most field systems, regardless its size or irrigated crop value, maintenance protocols are seldom implemented in full, and generally are only addressed when major system failures are detected, affecting crop yield and fruit quality, due to water supply interruptions during the repairing time span [39]. Maintenance is an important, though often overlooked, operation to extend not only the trouble-free life of the system itself but to maximize returns on investment. Preventative rather than corrective maintenance is more economical and less traumatic. The implementation of a maintenance program for drip irrigation systems will keep the system operating at peak performance and increase the system's work life expectancy. The best way to determine if the maintenance program implemented is effective is to constantly

It is one of the most important maintenance activities, to be performed during the postharvest winter period; if the total winter rainfall is below the average value of the area, it is necessary to operate the irrigation system at the beginning of spring, before crop budbreak (permanent orchards) or emergence (annual crops), when the spring root activity is initiated, in order to start the irrigation season with

Pumps, filters, and valves are dismantled in the control room, as well as the entire electrical installation, including power boards, irrigation programming

**16**

boards, filter back-washing boards, and all the fertilizer preparation and injection systems. In the field, mains, submains, manifolds, and irrigation laterals are washed to evacuate any sediment that may have precipitated and the emitters are revised to change those that are in poor condition. In persistent fruit orchards species, it may be necessary to continue watering in the winter, so this maintenance operation is performed after a significant rain.

The goal of the winter maintenance is to ensure that at the start of the new irrigation season, all equipment components are in optimal operative condition. The cost of this winter maintenance operation, including the cost of some spare parts that need to be replaced, plus the replacement cost of filtering media (quartz sand, meshes, and filter disks), generally represents 2–3% of the original irrigation equipment investment. Once the irrigation equipment has been reassembled after this winter maintenance, it is necessary to calibrate its operation, in terms of the emitters' discharge uniformity, operating pressures across the whole hydraulic network, and elimination of water leaks [40].
