Subsurface Drip Irrigation: Frequently Asked Questions

HOW LONG DOES IT TAKE TO DESIGN AND INSTALL A SUBSURFACE DRIP IRRIGATION SYSTEM?

At Southern Irrigation, the planning and product ordering process prior to installation takes a minimum of 3 months. The size of the project does not change this timeline.

The installation length depends on a few factors, including the size, shape, and topography of the land to be irrigated, the distance between the drip lines, the accessibility to water, and whether there is infrastructure in place. Some other SDI considerations include existing utility lines or irrigation district/environment approvals. For reference, the installation time for a 40-acre project can take about 1 month and a 625-acre project can take about 3.5 months.

HOW DEEP IN THE GROUND SHOULD YOU INSTALL A SDI SYSTEM?

The depth will vary depending on soil horizons, grower preferences, farm practices, and on the crops grown. The most common depth is about 12”, but as shallow as 10” and as deep as 16” is acceptable.

HOW MUCH SPACE IS NEEDED BETWEEN DRIPLINES FOR SDI?

The space between drip lines usually depends on the soil type and the crop(s) being irrigated. Common spacing is anywhere between 30”-60”.

HOW MUCH SPACE IS NEEDED BETWEEN EMITTERS FOR SDI?

The space needed between emitters is determined by the soil type and irrigation design. There is usually a space of 18”-30” between emitters.

HOW MUCH WATER DO YOU NEED FOR A SDI SYSTEM?

The amount of water needed will depend on the size of the land, the crop, and the climate. A properly designed irrigation system should be designed to meet the crop’s daily water uptake needs during the entire growing season.  However, since subsurface drip irrigation systems are 98% efficient (regardless of wind conditions) they can be designed to use less water. Learn more about SDI’s water savings.

DOES FIELD SLOPE AFFECT HOW SDI WORKS?

With a proper design, slope does not have much effect on a SDI system. Undulating terrain usually requires a pressure compensating dripline, ensuring low areas in the field will receive the same amounts of water as the high areas.

WHAT IS THE LIFE EXPECTANCY OF THE DIFFERENT PARTS OF A SDI SYSTEM?

A drip irrigation system that is well design, filtered, and properly maintained will last for over 25 years. Components such as valves and filters, if properly housed and maintained, will also last 25 or more years.

CAN WE FERTILIZE THROUGH THE DRIPLINE?

Yes, drip irrigation is ideal for fertigating as we can bring fertilizer directly to the root zone.

DOESN’T WATER ONLY MOVE DOWNWARDS?

Water movement varies depending on the soil type. Part of the design process will be to take a soil content probe at 0-6”, 6-12”, and 12-18”. Properly designed and installed, the water will move both downwards due to gravity, and upwards and outwards due to capillary action.

ARE THERE ISSUES WITH DRIP LINES PLUGGING?

By using Netafim’s advanced dripper construction and proper installation, operation, and proper maintenance and flushing procedures, the risk of drip lines plugging is insignificant. If this does occur, there are acids and chemicals that can be pumped through the lines to unplug the drippers.

IS THERE A RISK OF RODENT DAMAGE?

This is a recognized risk of any SDI system and there are many methods to reduce this risk as much as possible. These include packing/rolling the soil immediately following drip line placement, trenching, running water through the lines immediately following installation, use of bait and traps, fumigation, predator introduction, and habitat modification.

DOES THE SYSTEM NEED TO BE WINTERIZED?

This is a typical maintenance procedure as water will freeze and expand, possibly damaging plastic and metal system parts. Water from filters, valves, chemigation equipment, pressure regulators, subsurface pipes, and driplines should be emptied – especially at lower ends of the field where water typically accumulates. Polyethylene driplines are not subject to damage from freezing since drippers provide drainage points and polyethylene is flexible.

HOW MUCH DOES A SYSTEM COST?

Each field will have a customized plan based on a number of important factors – which will impact the overall system cost.  SDI has a very compelling ROI with a relatively short pay-off. We like to sit down and build a plan that includes the ROI metrics as a part of the SDI quote.

IS SDI RIGHT FOR ME?

SDI is the optimal water and fertigation management tool. The focus is on crop quality and increased yields, so SDI is not the answer for every grower or crop. There are many variables that need to be considered carefully. That is why it is so important to have a clear goal in mind before choosing to install an SDI system.

Speak to our team of qualified designers and agronomists to see if these goals can be reasonably achieved. We want successful systems with very clear and measurable returns on your investment!

2021-09-27T13:36:46-07:00September 20th, 2021|Subsurface Drip Irrigation|