Drip Irrigation Systems By: 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 Costs o Buying the initial system can be more than other systems o Systems can be more expensive because of the extensive piping needed ●Waste o 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 Conservation According 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 Lines o This is the distribution system for drip irrigation o PVC pipes and polyethylene pipes used in the system o Pipes generally 65 mm in radius ●Sub Main o Connected to main line through a control valve o Distributes the water laterally through the field

●Drippers/emitters o 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, shrubs 2. Container plants, hanging baskets, window boxes 3. 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 GPH drippers = 20 gallons/hour 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