Drip Irrigation SystemsBy: Philip Hanrahan and Matt Garrity

What is Drip Irrigation?

● Irrigation method that applies water to plants at a very low rate of application and without any pressure

● The concept of the system is to target the roots of the crop rather than the entire land area the crops cover

● Water is able to reach the deepest roots of the crop through capillaries and gravity

History● First experimented in the 1860’s in Germany using clay pipes● The first drip tape was first used in the United States in the

1960’s ● It was developed by an irrigation company called Netafin which

patented the first drip irrigation system ● These systems have become a valued innovation in agriculture

because it gives an alternative to surface irrigation.

Advantages over Surface Irrigation

● Less Irrigation Water Needed● Variation in Application Rates● Avoid Over Irrigation● High Yields● No Water Logging

Advantages (cont.)

● Reduced Labor Costs● Uniform Distribution of Water● Weed and Pest Control● Suitable for any type of land ● Maintain surface temperature

Disadvantages over Surface Irrigation

● High Costso Buying the initial system can be more than other systems o Systems can be more expensive because of the extensive piping

needed

● Wasteo Tubes for drip irrigation can have a short life span requiring

replacement pipes

Disadvantages (cont.)

● Clogging o When the water is not properly filtered, the

equipment could clog easily● Extra time and money for cleanup costs after harvest ● Not beneficial to crops that are closely panted together

(eg. wheat)

Irrigation Inefficiencies • UN World Water Development Report:

- About 70% of all water use worldwide is for agriculture irrigation

- 60% of agriculture irrigation water is wasted

• 50% of the water American’s use outdoors is wasted from inefficient methods

Global Water Distribution

Water ConservationAccording to the EPA:- Drip irrigation uses 20-50% less water than

pop up systems.- Can save the average American up to 30,000

gallons per year

Droughts● 2013 Government Accountability Office

survey stated that state water managers from around the country expect freshwater shortages to continue into the next decade.

Population Growth● An estimated 9.6 billion people by 2050● Approx. 2.5 billion more mouths to feed than

now

Drip Irrigation System Components ● Pumping set

o Generates pressure to control the amount of water supplied ● Filters

o Removes the impurities in the water

● Main Lineso This is the distribution system for drip irrigationo PVC pipes and polyethylene pipes used in the systemo Pipes generally 65 mm in radius

● Sub Maino Connected to main line through a control valve o Distributes the water laterally through the field

● Drippers/emitterso Connected on the laterals in order to emit water in

drops at a continuous flow rate o flow rates generally do not exceed 15 liters/hr

Example Layout of System

Installation

Getting Started● Compared to conventional systems, drip

irrigation systems are: - easy to design

- inexpensive- easy to install

Planning and Designing ● Recommended for:

- trees, shrubs, vines, roses, vegetables, flower beds, pots, and individual plants

● Create a plant list as well as a property sketch

About the Soil● Different soils require different drippers

- Sandy: 2 GPH drippers (10”-12” spacing)- Loamy: 1 GPH drippers (16”-18” spacing)- Clay: .5 GPH drippers (18”-24” spacing)

*GPH → Gallons Per Hour

How to Start a System● Not all systems are going to be the same, thus

multiple starting options.● Factors include:

- availability of water outlets- property lay out- types of plants

Method 1● Starting from a faucet for above ground

installation using 1/2” poly tubing

Method 2● Starting from an anti-siphon valve for above

or below grade installation

Method 3● Starting with an AC or DC in-line valve for

below grade installation

Method 4● Retrofitting an existing sprinkler riser into a

multi-outlet drip manifold head

Method 5● Starting from an existing riser using a

conversion elbow

Watering Methods● Different plants require different layouts

● Classifications:1. Roses, trees, shrubs2. Container plants, hanging baskets, window boxes3. Vegetable gardens, row crops

Roses, Trees, Shrubs

Container Plants, Hanging Baskets, Boxes

Vegetable Gardens, Row Crops

Calculating Water Flow Requirements● To determine the total flow, add up the total number of

drippers and their flow rates.Ex: A system using 40 drippers consisting of 20-1 GPH and 20-2 GPH drippers

- 20-1 GPH drippers = 20 gallons/hour- 20-2 GPH drippers = 40 gallons/hour

Total flow rate: 60 GPH/60 = 1 gallon/min*Max flow rate for single line ½” poly tubing is 220GPH/3.6GPM

Watering Schedule

Drippers and Spacing

Potential Problems● Controller does not work properly

- Check to make the battery is still working

● Drippers have uneven or no flow- check for mainline leaks or replace/clean drippers

● Drippers have uneven or no flow at end of line- make sure you have not go over max flow rate (220GPH)

Maintenance● Inspect drippers periodically to prevent

clogging● Filter screens should be cleaned once a

month● Tubing lines should be flushed once a month● During freezing weather tubing should be

drained and stored

Interesting Fact

● With marijuana production becoming a booming industry…-Drip irrigation is the most effective system for the plant and is widely used