Irrigation

What Is Hydroponics?

Hydroponics is the art of growing plants without soil. Instead of soil, hydroponics uses mineral nutrient solutions in water to feed the plants. The reason Hydroponics works is because it gives the plant the exact nutrients it needs, when it needs it, delivered right to the roots. It’s a much more efficient and dependable method for growing certain plant types. In fact, hydroponics is a proven method for growing vegetables faster with increased size and yield.

The most common form of hydroponics is a method where the plant roots sit directly in the nutrient rich water. This system of hydroponics is called Nutrient Film Technique or N.F.T.  But it’s not the only way to grow a crop using hydroponics.

Types of Hydroponic Systems

The Wick System

The wick system utilizes a number of wicks to draw the nutrient solution into the plants. One of the upsides of the wick system is that it has no moving parts. One of the downsides is that plants requiring high volumes of water may use up the nutrient solution faster than it can be supplied.

Water Culture

The most basic form of hydroponics uses a Styrofoam platform to hold the plants in place with the root system dangling into the nutrient solution beneath. Air is then injected into the nutrient solution to supply oxygen to the root ball. With the exception of lettuce, very few plants thrive in a water culture system.

Ebb and Flow System

In the ebb and flow system of hydroponics, the plants sit on a platform called a “grow tray”. A pump and timer is then used to flood the grow tray with nutrient water which then drains back into the tank beneath the tray ready for recirculation.

The Drip System

Just as it sounds, the drip system utilizes drippers to feed the nutrient solution to the base of the plant. The excess nutrient solution is recirculated back through a pump and timer.

N.F.T (Nutrient Film Technique)

When people think of hydroponics they typically think of the Nutrient Film Technique or NFT. NFT uses a pump to continually circulate water to the highest point where gravity feeds the water back through the plant to the holding tank. The plant itself is placed in a plastic holder with the roots protruding through to the nutrient solution in the holding tank.

Aeroponic System

The aeroponic system uses a nutrient filled mist, sprayed into the air by a pump and misting nozzles. Similar to the NFT system, the nutrients are largely fed to the plant through the air.

In each hydroponic example the water and amount of nutrients that is useable by the plant is affected by water hardness. The harder the water the more damage the water causes to both the plant and equipment. Even the nutrients are affected because hard water reduces the absorption rate of nutrients by the plant so you will need an increased volume of nutrient to grow your crop.

This can be fixed by installing a Softerwater Conditioner to the hydroponic system.

Softening the water in your hydroponic system will cause the water to mix better with the plant nutrients. This will make the nutrients more easily absorbed by the root ball encouraging more feeder roots giving you a healthier plant.

In the example of the Ebb and Flow, Drip, NFT and Aeroponic Systems a water softener can be attached after the pump to soften the water.  Installing a Softerwater Conditioner after the pump will soften the water and give the nutrient solution and water a thorough mix as the solution is recirculated time and time again.

What Is Irrigation?

Whenever water is artificially applied to land for agricultural purposes we call it irrigation. The most effective form of irrigation stimulates every step of the growth process from initial seedbed preparation, seed germination, growth of the root, supply and absorption of nutrients through to the quality and quantity of yield.

Why is irrigation used?

There are dozens of reasons why irrigation is used to farm crops. In general, irrigation allows primary producers to:

• grow a higher volume and quality of pastures and crops
• achieve good plant growth during times when access to water would otherwise be limited (due to a deficit in soil moisture)
• Achieve higher yields and meet market/seasonal demands during periods where rainfall is minimal
• Lengthen the growing season
• Time the start of a growing season in years where late rain would cause a late break in the season
• Provide ‘insurance’ against seasonal variability and drought
• Increase the volume of animals per hectare with tighter, more consistent pasture supply throughout the season
• Maximise benefits of fertiliser applications which require “watering in” for best results
• Increase useable land space by utilising land that would otherwise be considered too dry to farm
• Capitalise on market incentives given to primary produces for unseasonal production
• Reduce reliance on additional feeding in grazing operations due to the more reliable supply of feed grown with irrigation

There are 7 primary types of irrigation systems available on the market today

Center-Pivot Sprinkler Systems

• The center-pivot sprinkler is a self-propelled irrigation system with a single pipeline suspended 2 to 4 meters above ground and connected by a row of rotating towers. The water is distributed in a large circular area via sprinkler nozzles attached to the pipeline as the towers rotate around a pivot point.  The nozzles grade from small to large, with larger nozzles on the outside of the turning circle to maintain an even spread of nutrient distribution across all nozzle points.

Hand-Move Sprinkler Systems

• Just as the name suggests, the hand move sprinkler system is manually moved to ensure full coverage of the area to be irrigated. A hand-move system is a series of lateral pipelines attached to a mainline which can be either portable or buried. The Hand-move system is most suitable for small, irregular areas requiring irrigation and is typically used for smaller crops as a tall crop makes moving the pipelines difficult. A hand-move irrigation system is the most labour intensive of all irrigation types.

Solid Set / Fixed Sprinkler Systems

• Solid set /fixed sprinkler systems are typically found in orchards and vineyards and can be installed below the ground or along a wire or some other source of support. The solid set or fixed irrigation systems typically have exposed nozzles which drip or spray nutrients to the plant leaves or to the root ball. Solid-set systems are also widely used on turf and in landscaping.

Travelling Gun Sprinkler Systems

• The travelling gun system is a large, self-propelled sprinkler system mounted on a moving trailer or wheel. The sprinkler head is fed by a flexible rubber hose. The unit travels in a lane guided by a cable. The system requires high operating pressures as the pressure is used to both force water through the sprinkler to water the ground and to propel the wheel or trailer. 100 psi not uncommon.

Side-roll wheel-move systems

• The side-roll wheel-move systems use large-diameter wheels astride a pipeline, allowing the line to be rolled as a unit to consecutive positions across the field. The side-roll wheel-move system is not suitable or all crop types as the pipe sits approximately 1 meter above the ground.

Linear or Lateral-move Systems

• The linear or lateral-move systems are similar to center-pivot systems, with the exception that the lateral line and towers move in a continuous straight path across a rectangular shaped field. Water is supplied to the linear or lateral-move system via a flexible hose attached to the system of or pressurised from a concrete-lined ditch along the field’s edge.

Low-flow Irrigation Systems (these include drip and trickle)

• The low-flow irrigation systems (including drip and trickle) use narrow-diameter tubes located above or below the soil’s surface. The low-flow system is typically used in orchards, vineyards, or high-valued vegetable crops. Water is supplied frequently but slowly to the soil through small holes or emitters. The emitters receive the nutrient water via a network of main, submain, and lateral lines. The low-flow irrigation system is highly efficient due to the water being dispensed directly to the root zone, which avoids runoff and minimises water loss through evaporation.

The best-fit irrigation system for your operation requires knowledge of equipment, system design, plant species, growth stage, root structure, soil composition, and land formation. Choose an irrigation system that will boost plant growth while minimising associated problems such as salt imbalances, leaf burns, soil erosion, and water loss from evaporation, wind drift, and run-off.