Drip irrigation systems for farms

Types of drip irrigation systems

A drip irrigation system for farms is a controlled irrigation system that provides water to plants drop by drop, directly to the roots, using a network of valves, pipes, tubing, and emitters. This system minimizes water wastage and ensures efficient watering. Below are the main types of drip irrigation systems:

• Surface drip irrigation system

  This is the most commonly used type of drip irrigation system. It is laid on the surface of the ground and can be used in all kinds of soils and terrains. In this system, the mainline and sub-main lines are placed on the surface, with drip laterals connected to them. The emitters deliver water directly to the roots of the plants. This system is easy to install and affordable. However, it is less attractive and can be damaged by equipment or animals.

• Subsurface drip irrigation system

  This system is installed below the surface of the soil. The mainline and sub-main lines are placed below the surface, and the drip laterals are also buried in the soil. This system is suitable for sandy soils and crops with deep root systems. It minimizes evaporation and reduces weed growth. However, it is more expensive and complicated to install and maintain.

• Portable drip irrigation system

  This system is designed for small gardens, greenhouses, or areas with limited space. It is lightweight and can be easily moved from one location to another. The portable drip irrigation system consists of a pressure regulator, mainline, drip tubing, and emitters. It is easy to install and does not require electricity. However, it has a limited lifespan and is not suitable for permanent installations.

• Timed drip irrigation system

  This system uses a timer to control when the drip irrigation system is turned on or off. It is easy to use and helps save water. The timed drip irrigation system consists of a timer, pressure regulator, mainline, drip tubing, and emitters. It is suitable for all types of crops and can be used in all kinds of soils and terrains. However, it may not provide enough water for plants with varying water needs.

• Automatic drip irrigation system

  This system uses an automatic controller to regulate the opening and closing of the system. It is designed to work automatically without human intervention. The automatic drip irrigation system consists of an automatic controller, pressure regulator, mainline, drip tubing, and emitters. It is suitable for all types of crops and can be used in all kinds of soils and terrains. It is efficient and easy to use. However, it is expensive and complicated to install.

Design of drip irrigation systems

• Emitter

  The emitter, also known as the dripper, is a key component of a drip irrigation system. It is a small device attached to the drip line that regulates and releases water from the pipe to the plant base. Emitters come in various flow rates, measured in gallons per hour (GPH) or liters per hour (LPH). They can be pressure-compensating, non-pressure-compensating, inline, or online. The choice of emitter depends on the type of crop, soil, and climate.

• Drip lines

  Drip lines are the main pipes of a drip irrigation system. They are usually made from durable materials like polyethylene or PVC to resist corrosion and UV rays. The diameter of the drip tape can range from 1/2” to 4” or more, and the thickness of the tape can be 8 mils to 30 mils. Drip lines can be buried underground or left above ground. They are designed to be easy to install and repair, often featuring a snap-together design.

• Filters

  Filters in drip irrigation systems remove dirt, debris, and other impurities from the water to prevent clogging of the emitters and valves. There are several types of filters, including disc, screen, and sand filters. The choice of filter depends on the water quality and flow rate.

• Fertilizer Injectors

  Fertilizer injectors, also known as fertigation systems, are devices that automatically mix fertilizers and other nutrients into the irrigation water. This allows for precise and efficient delivery of nutrients directly to the plant roots. Fertilizer injectors can be venturi, pressure, or electric piston type. They are designed to be easy to operate and maintain, often featuring a user-friendly control panel.

• Air Vents

  Air vents are devices installed at high points in a drip irrigation system to release trapped air. They prevent water hammer, reduce pressure fluctuations, and prevent pipes from bursting. Air vents come in automatic and manual types. Automatic air vents open and close automatically to release or seal off trapped air. Manual air vents have a hand-operated valve that the user opens or closes to release or seal off trapped air.

• Valves

  Valves control the flow of water in a drip irrigation system. They can be manual or automatic. Automatic valves are often equipped with electric solenoids that open or close the valve when water flows through the valve. This allows for remote control and automation of the irrigation system. Valves are available in various sizes and pressure ratings to suit different applications.

Usage scenarios of drip irrigation systems

Around the world, farmers are using drip irrigation systems for various crops in different climates and soils. This is how they are using it:

• Crops in Arid Regions

  Farmers in the Middle East and parts of Africa with low rainfall and hot climate use drip irrigation systems. These areas need water-saving systems because water is scarce. The farmers supply water directly to the roots of crops such as olives, dates, and vegetables. This method reduces evaporation losses in the hot sun and conserves water for arid regions.

• Greenhouse Crops

  In controlled environments like greenhouses, drip irrigation is popular for high-value crops. Greenhouse tomato and pepper growers need precise water management for optimal growth. With drip systems, they can adjust water according to growth stages. This conserves water in greenhouses where every drop counts.

• Orchards and Vineyards

  Drip irrigation is widely adopted in orchards (e.g., apples, oranges) and vineyards (e.g., grapes). Farmers can control how much water each plant gets. This is important for fruit and wine quality. It also prevents overwatering, which can harm deep-rooting trees and vines.

• Vegetable Fields

  Many vegetable farmers now use drip irrigation for their fields, too. Whether growing carrots, lettuce, or beans, farmers can save water and reduce weed growth. Drip irrigation delivers water to the soil, which is absorbed by the roots. This is especially useful for delicate vegetables that cannot withstand water stress.

• Row Crops

  Drip irrigation is also used for some row crops like corn and potatoes. With plastic mulch over the soil, farmers combine drip irrigation and mulch. The mulch retains soil heat and moisture, while the drip waters the plants. This system is efficient for water-intensive crops.

• Restoration Projects

  Some conservationists use drip irrigation in restoration projects for native plants. When reintroducing species to a damaged ecosystem, precise watering helps them establish. Drip systems reduce water waste in projects aimed at environmental healing.

How to choose a drip irrigation system

• Field Size and Crop Type:

  For small-scale organic farms, a portable drip system is ideal, as it's flexible and covers varying field sizes. However, with larger fields or more permanent crops like orchards, a more permanent grid system, which is fixed and extensive, would be better.

• Water Source and Quality:

  Since drip irrigation conserves water, it's best for areas with scarce water sources. But if the water is muddy or contains animal waste, a filter is necessary to remove debris that can clog the drippers.

• Climate and Weather Conditions:

  In windy areas, it's important to choose heavier materials that won't blow away. Also, during hotter months, mulch or shade over the pipes can keep them cool and moist.

• Budget and Cost Considerations:

  Initially, portable drip systems might seem cheaper, but farmers should consider long-term water savings and the possibility of expanding for larger fields.

• Maintenance and Durability:

  Grid systems are more robust and less likely to burst compared to portable ones. But both need checks to ensure pipes aren't blocked by dirt or animal droppings.

• Ease of Installation and Use:

  Both systems come with user-friendly manuals. Yet, some farmers prefer systems that their neighbors are using, as they can assist during installations.

• Expandable and Future Needs:

  Portable systems can be added to, and as fields change, new parts can be acquired to accommodate different crops.

Q&A

Q1: What are the main benefits of using a drip irrigation system on farms?

A1: Drip irrigation systems for farms deliver water directly to the plant roots, thus minimizing water wastage and reducing evaporation. This system is ideal for areas with limited water supply or those wishing to conserve water. Besides, it promotes healthy plant growth, increases crop yields, and can be customized for different soil types and crops.

Q2: How does a drip irrigation system save energy?

A2: A drip irrigation system saves energy, as it usually requires less energy to operate than other irrigation systems, such as sprinklers. Besides, it saves energy in water pumping, as the system operates by gravity for some kinds of drip irrigation systems.

Q3: What types of crops can benefit from drip irrigation?

A3: Drip irrigation is versatile and can be used for various crops, including fruits, vegetables, nuts, and vineyards. It is suitable for row crops, orchard crops, and high-value specialty crops.

Q4: Can drip irrigation systems be automated?

A4: Yes, drip irrigation systems can be automated using timers, pressure sensors, and soil moisture sensors. This automation can further improve efficiency by ensuring that water is only supplied when necessary.

Q5: What are the maintenance requirements for a drip irrigation system?

A5: The main maintenance tasks include flushing the system to remove debris, checking and replacing damaged emitters, and ensuring that filters are clean. Regular inspection helps maintain system efficiency and extend its lifespan.