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Volume 06 - Issue 04 - April 2024 213 | P a g e
Technological Advances in Irrigation Management for
Protected Cultivation
Article ID: 48670
Surendra Lal1, Gopal Mani1
1Ph.D. Research Scholar, Department of Horticulture, college of Agriculture, G.B. Pant University of
Agriculture and Technology Pantnagar, U.S. Nagar-263145, Uttarakhand.
Technological advances in irrigation management for protected cultivation have revolutionized modern
agriculture. Precision irrigation systems, such as drip irrigation and hydroponics, optimize water usage by
delivering water directly to the roots of plants. Sensor-based technologies monitor soil moisture levels and
plant hydration, enabling farmers to adjust irrigation schedules in real-time. Additionally, automation and
remote-control capabilities allow for precise control and monitoring of irrigation systems, resulting in
improved crop yields, water conservation, and sustainability in protected cultivation environments.
Introduction
Plants rely on water, particularly within enclosed structures where natural rainfall is absent, and the
heightened warmth accelerates soil dehydration. Yet, in protected environments like polyhouses,
polytunnels and low tunnels where wind speed is nearly zero, many crops experience a notable decrease in
their water needs.
Using traditional watering cans is the most straightforward approach to addressing the watering needs of
plants. They excel in offering precise targeting for individual plants, especially in container gardening
scenarios. Nonetheless, when it comes to mass watering, such as in larger greenhouses, relying solely on
watering cans becomes impractical due to the labour-intensive nature of the task. Consequently, many
gardeners seek to circumvent these limitations by opting for hosepipes instead.
Why Protected Cultivation?
1. The produce cultivated within protected environments typically exhibit superior quality across various
parameters including fruit size, individual fruit weight, Total Soluble Solids (TSS), colour, texture, and
other quality indicators.
2. Productivity of crops within protected cultivation systems experiences a significant increase, often
ranging from 2 to 10 times higher compared to conventional methods.
3. Cultivating vegetables and other crops during off-seasons stands out as a pivotal aspect of protected
cultivation.
4. Within protected environments, the occurrence of pests and diseases is notably reduced owing to the
isolation from open fields.
5. Protected cultivation optimizes the utilization of two vital resources: land and water.
6. This method allows for year-round cultivation of single or multiple crops, yielding high-quality produce
with enhanced productivity.
Irrigation Techniques for Protected Cultivation
Greenhouse/shade Net house and walking/low tunnel: Achieving maximum benefits from protected
cultivation necessitates the adoption of micro irrigation and fertigation. A proficient irrigation system,
preferably micro irrigation coupled with fertigation, should be integral to protected cultivation. Selecting
the optimal irrigation approach predominantly relies on the size of the protected structure and the variety
of plants cultivated within. Frequently, the most efficient irrigation results from a blend of techniques.
Types of Irrigation Systems for Nurseries
Nursery operators must carefully consider which watering or irrigation system is most suitable for their
specific nursery size and type to ensure effective plant hydration.
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1. Overhead sprinkler irrigation systems: Nursery operators employing overhead sprinklers generally
have two choices. The initial choice involves rotary sprinkler heads, which feature a rotating nozzle
projecting a concentrated stream of water over plants. The alternative choice, stationary sprinkler heads,
directs a swift flow of water onto a plate, causing disruption that transforms the flow into a consistent
spray, effectively watering the plants.
While overhead sprinkler systems remain prevalent in nurseries, they are notably inefficient. They
necessitate high-pressure pumps, leading to substantial energy consumption. Moreover, approximately 80
percent of the water dispensed by overhead sprinklers is wasted.
2. Micro irrigation systems: Micro irrigation systems, renowned for their efficiency and ability to operate
under low pressure, encounter issues such as clogging from soil, algae, and chemical fertilizers in their
emitters. To address this, various filter options are available. Nurseries employ three main types of micro
irrigation systems, one of which is the capillary mat system. In this system, water is conveyed through
tubes into a mat, saturating it. Containers placed atop the mat then absorb water through their plant root
systems.
The alternative form of micro irrigation is referred to as a micro sprayer, micro-sprinkler, or spray stake
system. Recognized as one of the most effective nursery irrigation methods, micro sprayers transport water
directly into the soil through a tube connected to a water source.
The third variation of micro-irrigation is referred to as the spaghetti tube system. In this method of nursery
irrigation, slender tubes are employed to deliver water directly into the plant container. A small weight
positioned at one end of the tube ensures its stability within the container. Water moves through a capillary
network from one pore to another.
3. Capillary sandbeds: Capillary sand beds offer a low-energy alternative to traditional irrigation
systems like sprinklers and micro irrigation. Constructed with wood panels, a plastic liner, sand, a modest
water reservoir, a drainage pipe, and a valve, these beds are designed with a gentle slope. Water introduced
at the higher end gradually permeates through the sand to the lower end, ensuring a consistent and
uninterrupted water supply. With minimal upkeep required, capillary sand beds promote uniform plant
growth, reducing the reliance on fertilizers and pesticides.
Types of Mist Irrigation Systems Recommended in Poly House
Overhead systems: An overhead misting system comprises lines or sprinklers positioned beneath the roof
structure of your polyhouse, dispensing a gentle "rain" onto your plants. This irrigation setup is readily
automated and fosters elevated humidity levels. Such humidity serves as a protective shield against frost,
safeguarding your crops from potential damage.
Fig: Overhead Irrigation Systems Fig: Bench Irrigation Misting
Bench misting: Bench misting involves the installation of a central line of sprinklers or hoops positioned
either at the level of your plants or slightly above. This method necessitates the placement of plants on
elevated benches, typically constructed from water-resistant materials like metal. Alternatively, a self-
contained misting bench can be utilized, featuring a partial covering resembling a "roof" over the bench
area.
Drip irrigation system: Drip irrigation stands out as a highly efficient watering technique, boasting an
impressive 90 percent efficiency rate. Unlike traditional sprinkler systems, it minimizes runoff and
evaporation. This method involves the use of tubes equipped with emitters that run parallel to the plants
being watered. Water is released from these emitters at a slow drip directly into the soil around the root
Volume 06 - Issue 04 - April 2024 215 | P a g e
zone. Its effectiveness is particularly notable in greenhouse and tunnel settings, as it helps maintain lower
humidity levels, thereby reducing the likelihood of pest and disease issues.
Fig: Drip Irrigation System Fig: Ebb and Flow Tables Irrigation System
Ebb and flow tables: Ebb and flow tables are commonly employed in greenhouses for hydroponic plant
cultivation. However, they can also be utilized for traditional plant growth methods. In an ebb and flow
table setup, plants are placed in a tray equipped with a hose nozzle to introduce water and a drain at the
opposite end for water removal, providing flexibility for gardeners.
Hand watering: Hand watering represents the fundamental approach to greenhouse irrigation. By
utilizing watering cans or hoses equipped with nozzles, you can customize watering to suit the specific
requirements of each plant. However, this method demands considerable labour and may not be suitable
for larger greenhouse setups due to its labour-intensive nature.
Irrigation Scheduling
Greenhouse drip irrigation scheduling: The need to optimize agricultural productivity amid dwindling
water resources underscores the importance of efficient irrigation practices. This involves replenishing soil
moisture deficits in the root zone and maximizing water storage in the soil profile for subsequent crop use,
ultimately aiming for optimal yields. While different irrigation methods exist, the focus should be on
understanding crop response to soil moisture levels and irrigation strategies rather than the specific
irrigation technique employed.
In pursuing precise irrigation scheduling, four fundamental questions need addressing.
1. When to irrigate? (Frequency).
2. Apply enough water to replenish the soil's moisture level, adjusting for application efficiency, and
ensuring that variations in soil-water content are minimized, particularly with the frequent use of drip
irrigation.
3. Where to irrigate (point line/strip/disc source).
4. How to irrigate- drip (surface or subsurface) bubbler, micro sprinkler and mist etc.
In conclusion, technological advances in irrigation management for protected cultivation have
revolutionized agricultural practices, offering precise control over water delivery, optimizing resource use,
and enhancing crop yield and quality. These advancements signify a significant step towards sustainable
and efficient agriculture in the face of environmental challenges.