Drip Tape Irrigation

Drip irrigation is the most efficient system for supplying water and nutrients to a crop and it comes with a multitude of benefits. In this type of irrigation system, water and nutrients are slowly and uniformly delivered directly to a plant's root zone. Below is an overview of a drip tape system showing the main components.

Benefits of Drip Irrigation

Saves Water – Drip irrigation systems use 30-50% less water than conventional watering methods, such as sprinklers.
Saves Labor – Moving sprinklers around is not necessary with drip irrigation. Using a timer, your drip irrigation system can become totally automatic.
Saves Energy – Since drip irrigation is low pressure and low flow, it does not require the same high-pressure pumps that sprinklers do.
Better Growth – Small amounts of water applied over a long period of time create ideal growing conditions. Drip irrigation's slow and continuous flow allows water to deeply penetrate a plant's root zone while limiting plant stress, erosion, and nutrient runoff. You can also inject fertilizer directly into the drip line or drip tape where it will be applied straight to the plant's roots.
Better Seed Germination – Seeds are kept moist which helps them crack and sprout easier.
Better for Clone Transplants and Starts – Clones and starts need light and frequent watering. Drip irrigation is perfect for doing this.
Discourages Weeds – Since water is applied only where it needs to be, weed growth is minimized. Lightly burying drip tape or drip line will reduce weed growth even further and without the need for plastic mulch.
Helps Prevent Fungal Diseases – Fungal diseases thrive under moist conditions. Wet foliage can spread disease.

Setting up a drip tape system can be very simple. Here are some things you should know about drip tape:

Filtration

You will need a filter so you don't clog the tape. You can use a screen filter or disc filter. The larger the filter, the longer you can go between filter cleanings.

Pressure Regulation

Normal operation pressure is 8-10 PSI for drip tape with a maximum pressure of 12-15 PSI depending on mil thickness. Pressures higher than this can damage the tape or cause it to burst so you will need a pressure regulator.

Air Vents

Air vents can help keep the drip tape clean. When you shut down your drip tape system, a powerful vacuum is created. This can cause your lay flat header and drip tape to collapse. When this happens, air and dirt can be sucked into the system through the drip tape emitters potentially clogging them. Installing air vents can alleviate this problem.

Header Line

Your header line can be poly tubing, PVC pipe, or lay flat hose. Lay flat hose is very common because it is easy to set up, comes in medium to large diameters, and is inexpensive. Make sure you size your header line appropriately based on the length and flow rate of your system. Use a pressure loss calculator to help you determine this.

Length of Run

This is between 260 and 1500 feet depending on the flow rate and diameter of the tape. 600-700 feet is typical. Lower flow and larger diameter tape allows for longer run lengths.

Flow Rate

Drip tape comes in different flow rates. The flow rate is usually measured in GPM per 100 feet. This flow rate is calculated by combining the emitter flow rate and emitter spacing.

Emitter Spacing

Spacing between emitters can be 4" to 12". 8" and 12" spacing are the most common.

Wall Thickness

This ranges from 5 to 15 mil with 6 and 8 mil being the most common.

Diameter

Standard drip tape diameter is 5/8". For longer runs, 7/8" is used.

Roll Length

This varies by wall thickness. 7,500' for 8 mil 5/8" tape or 10,000' for 6 mil 5/8" tape.

Longevity

Drip tape can last for 2-3 seasons but typically is used for just one. A thicker wall tape will last longer. Lightly buried tape will also last longer.