Micro Irrigation Techniques

Prepared By

Mountain Harvest OrganicsCarl Evans and Julie Mansfield

77 Wyatt LaneHot Springs, NC 28743

Phone 828-622-3654

Overview

The primary purpose of this guide is to provide the grower with the necessary information to select andinstall an irrigation system that eliminates much of the trial and error normally associated with such a project.The information within this manual is largely practical in nature and in many cases does not attempt toexplain the theory behind the design. However, for those interested in the theory, the Resources chapterprovides a list of the sources explaining the details behind the practical information.

Micro irrigation is the precise, slow application of water as discrete drops, continuous drops, small streams,or miniature sprays through mechanical devices called emitters at low water pressure. The theory behindmicro irrigation is applying sufficient moisture to crop roots, which will help prevent water evaporation,runoff, and loss of water do to the effects of wind. Traditional overhead irrigation is applying a large volumeof water at once to a large area. Typically traditional overhead irrigation is normally easy to install and willcover a large area with limited equipment but it requires a large water pump and a large volume of water.Although overhead irrigation is still practical some cases, such as for frost prevention, in many cases growersmay want to consider replacing traditional overhead with micro irrigation systems to conserve waterresources and reduce the potential for disease.

Chapter

1

Design Goals Configure a system that is affordable for the small grower and scalable to accommodate larger

growers.

This design goal was accomplished with the combination of purchasing components locallywhenever affordable and possible, otherwise mail-ordering from suppliers. The design of oursystem can be scaled to meet the needs of a larger grower because the components are modular andscaleable.

Flexible for crop rotation with modular components.

Being an organic grower, we minimize disease and pests by rotating our crops to different growingareas. Because our growing areas are not the same size, our micro irrigation system design needed tobe flexible so that it could easily be adapted to a field of any shape or size. This design goal wasaccomplished by having a main line configured for each specific field size then using sub-mains thatcan be moved along with the crop rotation.

To reduce downtime by decreasing single points of failure and having spared pats available.

We hope to accomplish this design goal by identifying the parts of the irrigation system that are mostlikely to fail and keeping those as spare parts in our inventory. We have not had our irrigationsystem long enough to know if we have met this goal.

Reduce costs through reuse of expensive components across all fields.

We accomplished this design goal by using the most expensive parts, such as our pump and sandfilter, across all growing areas. We have designed a way in which our pump and sand filter can easilybe connected in our various growing areas which allows those components to be re-used across allgrowing areas, while minimizing the setup time required.

Provide water to plants while minimizing disease, pests and weeds.

We accomplished this by designing our irrigation system so that drip tape would be used to irrigatecrops most susceptible to leaf spot, while using overhead irrigation for other crops. In growing areaswhere we have problems with weeds, we tend to use drip irrigation so that our crop is watered, butnot the surrounding area, thus reducing the growth of weeds.

Provide an environmentally friendly watering system.

We accomplished this design by using drip irrigation whenever possible research has shown thatwater savings with drip irrigation can amount to as much as 80% compared to subirrigation and 50%compared to overhead sprinkler irrigation (Locascio et al., 1981b; Elmstrom et al., 1981; Locascio etal., 1985) Since water is applied directly to the root zone, water evaporation, runoff and water lossdue to wind are minimized.

Reduce labor costs with fertilizing operations

We accomplished this design goal by installing a fertilizer injector that may be installed for an entirefield or for a particular row. Normally we fertilize using backpack sprayers, so this will save timefrom having to manually fertilize all our crops.

Cost/BenefitMountain Harvest Organics does not have the background necessary to know the true cost/benefits ofirrigation. We knew that it was necessary to irrigate to increase our yield and justified implementation of amicro irrigation system based on the following information:

• Micro Irrigation is said to be cheaper to implement and maintain

Statistics exist indicating that traditional overhead irrigation for one acre of land costs $1,601.17annually while a micro irrigation system on one acre for the same time period of time costs$1,112.47. The costs of irrigating with a micro irrigation system decrease when little or no damage tothe distribution lines occurs by machinery, crew, insects or rodents, or efficiencies in the time tooperate the system improve.

• More environmentally friendly

Research has shown that water savings with drip irrigation can amount to as much as 80%compared to subirrigation and 50% compared to overhead sprinkler irrigation (Locascio et al.,1981b; Elmstrom et al., 1981; Locascio et al., 1985) Since water is applied directly to the rootzone, water evaporation, runoff and water loss due to wind are minimized.

The energy efficiency of micro irrigation comes from the savings of capital costs such as smallerpumps and smaller diameter pipes, as well as decreased energy in the form of fuel and/or tractorusage.

Improvement in crop uniformity, quality and early maturity

Research has shown that irrigating crops can increase yield by 65% more. Being a small grower,it is necessary to figure how we can increase our yield. In addition, we hope to grow high-qualityproducts, and because the use of irrigation has show to produce more uniform crops, we attainone of our goals of “quality”

It has said that many leaf spot diseases may be prevented using drip irrigation as it tends to keepthe leaves dry. This can also be prevented if using overhead sprinklers by scheduling thewatering during predawn hours or midday to minimize wetting of the leaves.

Ability to more reliably start fall crops where rainfall is less frequent

We hope to extend the season with use of irrigation. Irrigation should allow us to start crops latesummer for the fall markets.

Major Components

The main components for a micro irrigation system include: water source, pump, filter, main distributionlines, field distribution lines, connectors and valves, emitters, fertilizer injectors, and pressure gauges andregulators.

Water SourceThe water source will dictate to a large degree what type of system that can be installed. The critical factorsto be considered are the volume of water as measured in gallons per minute (GPM), the amount of foreignmatter in the water, and distance and terrain of the water source to the field. Typical water sources includecity water, wells, ponds, creeks and branches. In Madison County, we are lucky to have branches and creeks,but must use them with caution because they may go underground during the summer.

To determine the gallons per minute of your water source, using a second hand watch, time for one minutehow long it takes to fill a five gallon bucket. Calculate the gallons per hour by multiplying theGallons/minute x 60 = Number of gallons per hour. Remember that you cannot use all the available wateror you will have no water pressure in the outlying parts of your systems.

Elevation must be considered in your irrigation design because it affects water pressure within the system.Pressure changes by 1 pound for every 2.3’ in elevation or roughly 4 pounds for every 10’ of vertical change.Pressure compensating emitters are designed to work in areas with significant changes in elevation.

Distance of your run from your water source to the final destination must be considered in your designbecause pressure is lost due to friction. In main line runs of more than 200' there can be a significant drop inpressure that can lower the output of some emitters or sprayers at the end of the line. To decrease frictionsimply increase the size of the main water line.

PumpsThe most common type of irrigation pump is a centrifugal pump, which means it works by turning animpeller that throws the water to the outside edge of the pump housing. Centrifugal pumps are best suitedto transferring relatively large quantities of water at moderate pressures. There are two main power sourcesfor pumps of this type, electric and gasoline.

Chapter

2

Pump pressures required for trickle irrigation are typically 50-60 PSI. Solid set sprinkler and reel irrigationrequire 90-120 and 150-180 PSI pump pressures respectively.

Typical pump pressures for micro irrigation are 50-60 PSI. Traditional overhead irrigation systems require90-120 and 150-180 PSI pump pressures respectively. The energy efficiency of micro irrigation comes fromthe savings of capital costs such as smaller pumps and smaller diameter pipes, as well as decreased energy inthe form of fuel and/or tractor usage.

FiltrationThere are four types of filters: sand media, cyclone sand separators, disk and screen. Growers should followrecommendations given by manufacturers for each of these filters. Where no recommendations are available,the general practice is to filter to one-tenth of the diameter of the emitter's smallest opening. Filtration unitsshould be designed with at least 20% extra capacity. When choosing your filter, you will first need tounderstand your water quality. The below chart can help determine your filtration needs based on theparticle you wish to filter. Many of the heavy-duty filters come with pressure gauges permanently attached tothe filter so the pressure can be monitored because a decrease in pressure may indicate that the filter needscleaning/backflushing. Any time a filter is included in the design of the irrigation system, consider providinga means to use a pressure gauge to check pressure.

Particles and their Filtration Requirements

Particle Diameter (mm)Coarse sand 0.50 to 1.00Fine sand 0.10 to 0.25Silt 0.002 to 0.05Clay < 0.002Bacteria 0.0004 to 0.002Virus < 0.0004

Filter Recommendations

Water Source FilterMunicipal Water System Screen Filter, Centrifugal Filter, or Disk Filter.Well Screen Filter, Centrifugal Filter, or Disk Filter.

River or Creek Disk Filter, Media Filter and Screen Filter,Centrifugal and Media Filter.

Pond or Lake Disk Filter, Media Filter and Screen Filter,Centrifugal and Media Filter.

Spring or Artesian Well Screen Filter, Centrifugal Filter, or Disk Filter.

Organic material in water Disk Filter, Media Filter and Screen Filter,Centrifugal and Media Filter.

Sand in water Screen Filter, Centrifugal Filter, or Disk Filter.

Media FiltersMedia filters clean the water by forcing it through a container filled with a small, sharp edged, media and areone of the better filters for removing fine gravel and sand in moderate to heavy dirty water situations. Themedia filter is not easily clogged with algae, however it does provide favorable conditions for bacterialgrowth. This filter uses sharp sand to remove large amounts of organic and inorganic particles. In mostcases the media material is uniform sized, crushed sand which has sharp edges that snag the debris – it is veryimportant to buy high quality media. Media filters are the type of filters most commonly used for highvolume cleaning of water from rivers and lakes. Media filters are cleaned by backflushing which forces waterbackwards through the filter, lifting and separating the media to free debris, then washing it out through aflush valve. Because a small amount of media is often washed out too, it is necessary to periodically addsome more to the filters. Because sand is not easily flushed out of them, media filters are not good forsituations where the water contains a lot of sand. The sand will not flush out and soon the filter will becompletely filled with sand which you will have to remove by hand. Media filters must be carefully matchedto the system flow rate for proper operation. Always consult the media filter manufacturer's literature forproper sizing to meet your needs.

Sand media size and screen mesh equivalent

Sand No. Effective Sand Size (in) Screen Mesh Size Micron8 0.059 70 Unknown11 0.031 140 15216 0.026 170 10420 0.018 230 7330 0.011 400 Unknown

Centrifugal FiltersThese filters are great for situations where a lot of sand is present in the water because they don't clog upnearly as quickly as other types of filters, however they are ineffective in removing most organic solids. If theamount of sand in the irrigation water is small, screen filtering will usually be adequate and a sand separator isnot required. The dirty water enters the filter where it is swirled around the inside of a cylinder. Thecentrifugal force causes the sand particles to move to the outside edge of the cylinder where they graduallyslide down the side to a holding tank at the bottom. Centrifugal filters are reasonably inexpensive, verysimple, and are very effective for removing sand from water. Many times these are used with well pumpsbecause these pumps tend to pump sand up along with the water. For micro irrigation systems, a "backup"screen filter should be used in conjunction with the Centrifugal Filter as a safety precaution. A centrifugalfilter used in combination with a media filter is an excellent combination. The centrifugal filter pulls out thesand then the media filter removes debris. Always consult the manufacturer's sizing guidelines whendesigning a centrifugal filtration system for your irrigation system.

Disk FiltersDisk filters are very commonly used in relatively clean water situations. The disk filter is a hybrid of screenand sand media filters and used where water contains moderate levels of organic contaminants. The disks ofthe filter are 3-dimensional and lock together to provide excellent filtration. Disk filters separate duringbackflushing and require less water than media filters. However, backflushing pressure as high as 50 psi maybe required, which may require use of a booster pump. A typical recommended flow rate for filteringgroundwater with 200-mesh-equivalent disk filters is 50 gpm per square ft of filter area. This system requirescleaning depending on the quality of the irrigation water.

Screen FiltersScreen filters are probably the most common filters and in most cases the least expensive. Screen filters areexcellent for removing hard particulates from water, such as sand but are not good at removing organicmaterials such as algae, mold, and slime. These non-solid materials tend to embed themselves into thescreen material where they are very difficult to remove. In other cases they simply slide through the holes inthe screen by temporarily deforming their shape.

Screen filters are cleaned by flushing them with a stream of water or removing the screen and cleaning byhand. Depending on the flush method used, you will probably have to periodically hand clean the screen toremove garbage not removed by flushing. Several methods of flushing are common. The simplest is a flushoutlet in which the outlet is opened, water is force through the outlet to wash out debris. An improvedvariation on this is the directed-flow flush. Again a flush outlet is opened, but in this case the structure of thefilter is designed so that the flush flow rushes over the face of the screen sweeping the debris along with it.Somewhat like hosing off a sidewalk with a strong stream of water. This is the most common method foundin inexpensive filters. The most effective method of flushing is the backwash method, but these filters aretypically more expensive.

Mainline and Sub-main distribution linesThe mainline and sub-main are the distribution lines that carry water from the pump to the edge fielddistribution lines. Typically the main and sub-main distribution lines are a larger pipe size than the fielddistribution lines because they need to carry more water. The mainline and sub-main may be aluminum,steel, PE, or PVC. The mainline should be a minimum of Class 9 or one class higher than that required forthe operating pressure so the pipe is capable of handling extra pressure caused by water hammer andblockages. Mainlines located in the center of the property are more economical than edge mainlines, sincethey create shorter laterals, which in turn reduce the friction losses. On steep slopes, the mainline is generallydesigned to go up and down the hill. Plastic pipe is economical, relatively easy to install, and non-corrosiveto most chemicals injected into the system, therefore it is one of the more common pipes used in irrigationsystems. If PVC pipe is used, protect it from the sun to prevent degradation..

Sub-main lines may connect to the mainline with a shut-off valve to allow partial watering of the field shouldthe grower use stagger planting or wish to irrigate the partial field. When choosing a shut-off valve, considera ball valve because it won’t restrict water flow.

Flush valves should be installed on the mainline so the system can be flushed periodically during the season.During this draining process, accumulated precipitates and particulate matter are discharged from the tube.This valve can either be manual or automatic. Automatic flush valves automatically flush laterals at eachirrigation. Most automatic flush valves are open when there is low pressure in the laterals but close when thepressure exceeds 1 or 2 psi. This means that a small amount of water is flushed through the valves as thepressure builds up.

The sample configurations included with this manual consist of 1 _” Layflat hose that goes from the pumpto a manifold in the center of a growing area.. The manifold allows for multiple _ acre fields to be watered atone time. Each field in the growing area will have a 1 _” Flatube mainline with a 1 _” threaded end cap.(See Figure B.) The threaded end cap allows the mainline to be flushed and pressure tested. When sizingyour mainline pipe, consider that you may need to repair line breaks, therefore size the tubing so that if acoupler is needed, the minimum water throughput will still be large enough to carry water to your sub-mainand field distribution lines. In addition, the pipe pressure rating should be higher than the pressure plannedfor the system so should the system clog, pressure buildup will not burst the pipe.

The following table provides estimates for the flow in gallons per hour of various sizes of pipe. The size ofthe pipe is only one factor that affects the flow rate, another critical one is the friction loss as the water flowsthrough the pipe. On long runs of tubing the friction loss can be substantial and different types of hoseshave different degrees of friction. I have not yet found any figures on the amount of friction created bydifferent types of hose.

Pipe Size Flow Rate_” 300 GPH – Dripworks quotes 240 GPH_” 700 GPH – Dripworks quotes 480 GPH1” 1,200 GPH1 _” 1,900 GPH1 _” 2,700 GPH2” 5,000 GPH3” 10,500 GPH

Field distribution linesThe field distribution lines carry water from the mainline and/or sub-main to through the filed and haveemitters attached that release water in the field. Typically these lines are smaller than the mainline and/orsub-main because they don’t need to carry as much water. It is recommended that they have end caps so theline may be flushed.

EmittersA small device that is connected to the field distribution lines and controls the flow of water going to the soil.Emitters come in many different flow rates and styles. Most emitters emit 4 liters/hour (4,0/hr) of water orabout 1 gallon per hour (GPH). It is recommended that pressure-compensating emitters be used in hillyareas. The pressure compensating emitters normally don’t work well under 10 PSI so this should be a factor

when choosing your emitters. When determining the types of emitters to be used, take into considerationthe area to be irrigated because the higher volume emitters may not support a large area. Multi-outletemitters are available but have known to be more troublesome so avoid if you desire a trouble-free dripsystem.

Drip tape normally has emitters pre-installed from the manufacture in varying distances and volume of waterreleased. Use calculations from the manufacture when deciding on the type of emitters. The volume ofwater from your water source must be greater than the volume of water released in the irrigation system.When designing your drip irrigation system, use a maximum of 80% of your water source to be available foryour drip lines. If you are trying to irrigate a large area, you may need to consider the emitters that release alower volume of water.

Mini-Wobblers are a type of micro overhead irrigation. These may be an economical way to irrigate a givenarea, especially if it is important that the entire seed bed be irrigated. They typically will use more water thanwith drip irrigation.

Fertilizer InjectorsThere can be a huge labor savings in fertilizer management with a micro irrigation system that uses a fertilizerinjector. Several types of injection systems are available to apply fertilizers through a micro irrigation system.The major groups include positive displacement (hydraulic or electric powered) pump injectors, pressuredifferential systems, and venturi injectors. The choice of a particular injector depends on the desiredlongevity of the piece of equipment, the required accuracy of injection, the required injection rate, andwhether or not corrosive chemicals such as acids will be injected.

Some positive displacement injectors are water powered, requiring a portion of the irrigation water to drivethe injection pump. Some types of pumps discharge this water onto the ground. Other pumps reinject itback into the irrigation system. All injection systems which do not have an external power supply (usually anelectric motor) suffer a pressure loss across the injector or proportioner. Sometimes this pressure loss is greatenough to eliminate the use of a particular injection system.

Location of the fertilizer injector or proportioner should be carefully considered in the design of an irrigationsystem. It is important to locate the injector so that relatively small amounts of water are delivered to the fieldbefore the fertilizer reaches the crop. Irrigation systems that have long or large mainlines and sub-mains thatmust be filled with water before the irrigation water finally reaches the irrigated crop, may experienceproblems when the fertilizer is injected in frequent, small doses. In these systems, the mainline and sub-mainmust be filled with water to bring the system up to pressure before the fertilizer is injected. Therefore, a largeamount of water must be delivered to the crop before the fertilizer can reach the crop. The potential for overwatering a crop is high when the fertilizer injector is not located near the point where water is finallydelivered to the crop. It is convenient to locate the injector near the pump and irrigation controller so that allof the components can be easily monitored. However, injection points remote from the control station maybe required to obtain an adequate uniformity of fertilizer application.

Pressure Regulators and GaugesMicro irrigation requires pressure regulators because the emitters must operate at a specific pressure so apressure regulator is required to control the pressure properly. Pressure regulators are used to provideconstant pressures to the irrigation system, a subset, an individual line, or any combination of positions.Location and the number of regulators will depend on the desired level of system control.

Pressure gauges are necessary to monitor the system operating characteristics. A pressure gauge is a necessarytool that may be used to trouble-shoot problems with the irrigation system, in determining whether filtrationsystems are clogged or in need of backflushing, and for understanding how the irrigation system isoperating.  Decreases in system pressure can indicate broken lines and increases in pressure can indicate pipeblockages. It is recommended that pressure gauges be installed after your filter(s) to help in knowing whenthe filter needs cleaning/backflushing.

Miscellaneous Tools and Components

• Tensiometers is a tool used for monitoring the soil moisture down in the root zone

• Rain Gauge is hung outside so the grower can adjust the irrigation system to accommodate naturalprecipitation.

• Reduced Pressure Backflow Preventer. If you are fertilizing or applying pesticides using an injector,and you are using your home well, creek/branch, or city water, this is required. It prevents fertilizersand pesticides from backing up into your water source.

• Cart. Our pump and sand filter will be shared across remote growing areas so we have a cart thatwill be used to transport our pump and filter to the various growing areas.

• Controllers and Timers. Drip Irrigation can be automated with the use of a timer. In order toautomate irrigation, you will need a water source other than a gas pump.

• Punch for barbs. This inexpensive tool punches the correct size hole in poly tubing to accept barbsfor emitters and saves your hands from being cut trying to use a twist drill bit.

• Pressure Gauges. Used to understand how the system is working, to trouble-shoot problems withthe system and to know when filters are in need of cleaning.

MaintenanceTo obtain maximum benefits from drip irrigation, the system must maintain a high degree of uniformitythroughout the season, uniformity being the distribution of even amounts of water and fertilizer to all partsof the system. Uniformity of the system can decrease through the season if there are problems or failures inthe components of the system such as pressure regulators or if drippers become clogged. Keep in mind thatif the system does not distribute water evenly, then if using a fertilizer injector, the fertilizer won’t bedistributed evenly. Micro irrigation systems should be checked periodically for water flow uniformity bymeasuring the flow from various emitters in the field.

Greenhouse Irrigation

Chapter

3

Sample Configurations

Drip Irrigation – Row Crops

Chapter

3Chapter

4

1 1/4" Flatube

25'-0

"25

'-0"

12'-0

"25

'-0"

12'-0

"

FigD

200'-0"

100'

-0"

100' x 200' Field Layout with T-Tape

Mainline 1 1/4"Sub-main - 3/4"

Legend

FigB

Manifold

1 1/2" Layflat hose

Pump

Scale: 1" : 25'

0 0 15 0 25 0 50 0

MediaFilter 1 1/4" barb x 1 1/4" MPT

and 1 1/4" threaded cap

24'-0

"

3/4" Figure 8hose ends

T-Tape Drip Line - 5/8"

T-Tape lines spaceddepending upon crop

FigA

Bill of Materials for 100' x 200' field with T-Tape

Component Description Qty Unit Cost Total Cost Source Part Number

PumpPacer 3.5 HP 150GPM self-priming 1 209.00 209.00 Tractor SupplyHose Kit for pump 1 85.00 85.00 Tractor SupplySubtotal 294.00

Filtration (optional for mini-wobbler)Sand Media Filter 1 229.00 229.00 Dripworks FMED50Filtering Sand - 50 lb bags 5 8.00 40.00 Swimming Pool SupplyPressure Regulator - 1 1/2" Netafim, high flow 1 27.50 27.50 Dripworks PR112NETPressure Regulator springs - 50 PSI 2 1.90 3.80 Dripworks PRNSP50Subtotal 300.30

Manifold1 1/2" Layflat tubing - length varies - average 100' 100 0.50 50.00 Dripworks LF1121 1/2" PVC male adapter 1 0.58 0.58 Lowe's1 1/2 PVC triple Y 1 2.50 2.50 Lowe's1 1/2" PVC Schedule 40 pipe - 10' long 1 2.63 2.63 Lowe's1 1/2" PVC slip to 1 1/4" MPT 3 0.50 1.50 Lowe's1 1/4" PVC Schedule 40 threaded ball valve 3 8.24 24.72 Lowe's1 1/4" Schedule 80 nipple - 2" long 3 0.50 1.50 Lowe's1 1/4" Schedule 80 threaded union 3 2.94 8.82 Dripworks P114TUSubtotal 92.25

Pressure RegulatorPressure Regulator - 1 1/4 FPT inlet x 1" FPT outlet 1 14.00 14.00 Dripworks PRSH101 1/4" nipple 2 0.30 0.60 Lowe's1" MPT x 1 1/4" slip 1 0.50 0.50 Lowe's

1 1/4" female adapter 1 0.50 0.50 Lowe's1 1/4" Schedule 80 threaded union 3 2.94 8.82 Dripworks P114TUSubtotal 24.42

Mainline1 1/4" Flatube tubing - price per ft (500' roll) 150 0.15 23.10 Dripworks F1145001 1/4" combination tee with 3/4" FPT 4 1.90 7.60 Lowe's1 1/4" male pipe end 2 0.43 0.86 Dripworks BMP1141 1/4" hose clamps 10 0.75 7.50 Dripworks BSHC1 or BSHC1121 1/4" PVC threaded cap 1 0.25 0.25 Lowe'sSubtotal 39.31

Distribution3/4" MPT x 3/4" MHT adapter 4 0.50 2.00 Dripworks AMHMP3/4" compression tee with female hose end 4 1.25 5.00 Dripworks CST343/4" figure 8 hose ends 8 0.21 1.68 Dripworks CF8343/4" nipple (optional) 4 0.30 1.20 Lowe's3/4" threaded ball valve (optional) 4 2.50 10.00 Dripworks P34BVT3/4" poly tubing - price per foot 100 0.07 6.60 Dripworks 34500Subtotal 26.48

EmittersT-Tape 10 mil - 200' x 30 runs (price per foot) 6000 0.02 135.00 Dripworks T1008LRTape-loc fitting with 1/4" barb 30 0.39 11.70 Dripworks LSBT-Tape grip sleeve ends 30 0.13 3.90 Dripworks LSGSSubtotal 150.60

Total Cost of field (Mainline, Distribution and Emitters) 216.39Total Cost of system 927.36

Overhead – Row CropsThis sample configuration is designed to irrigate a 100’ x 200’ field using small sprinklers that throw a circle ofwater approximately 35 feet in diameter. The sprinklers are mounted on top of _ PVC tubing cut into 40”lengths that have been driven into the ground about 6 inches. This configuration is intended to irrigate cropsthat require an evenly moist seedbed

1 1/4" Flatube

3/4" poly pipe

25'-0

"25

'-0"

12'-0

"25

'-0"

12'-0

"

FigC

R 17'-6"

30'-0" 30'-0"

200'-0"

100'

-0"

30'-0" 30'-0" 30'-0" 30'-0"

100' x 200' Field Layout with Mini-WobblersFigB

Manifold

1 1/2" Layflat hose

Pump

MediaFilter

14'-6"

30'-0"2'-6"

3/4" compressionhose end w/cap

1 1/4" barb x 1 1/4" MPTand 1 1/4" threaded cap

MainlineDistribution Line

Legend

Mini-wobbler and circleof water

Scale: 1" : 25'

0 0 15 0 25 0 50 0

FigA

Bill of Materials for 100' x 200' field with Mini-wobblersComponent Description Qty Unit Cost Total Cost Source Part Number

PumpPacer 3.5 HP 150GPM self-priming 1 209.00 209.00 Tractor Supply

Hose Kit - includes 20' suction hose, 25' discharge hose,suction hose strainer, 2" pump fittings and quick connectcouplers 1 85.00 85.00 Tractor SupplySubtotal 294.00

Filtration (optional for mini-wobbler)Media Filter 1 229.00 229.00 Dripworks FMED50Filtering Sand - 50 lb bags 5 8.00 40.00 Swimming Pool SupplyPressure Regulator - 1 1/2" Netafim, high flow 1 27.50 27.50 Dripworks PR112NETPressure Regulator springs - 50 PSI 2 1.90 3.80 Dripworks PRNSP50Subtotal 300.30

Manifold1 1/2" Layflat tubing - length variable - average 100' 100 0.50 50.00 Dripworks or Tractor Supply LF1121 1/2" PVC male adapter 1 0.58 0.58 Lowe's1 1/2 PVC triple Y 1 2.50 2.50 Lowe's1 1/2" PVC Schedule 40 pipe - 10' long 1 2.63 2.63 Lowe's1 1/2" PVC slip to 1 1/4" MPT 3 0.50 1.50 Lowe's1 1/4" PVC Schedule 40 threaded ball valve 3 8.24 24.72 Lowe's1 1/4" Schedule 80 nipple - 2" long 3 0.50 1.50 Lowe's1 1/4" Schedule 80 threaded union 3 2.94 8.82 Dripworks P114TUSubtotal 92.25

Mainline1 1/4" Flatube tubing - price per ft (500' roll) 150 0.15 23.10 Dripworks F1145001 1/4" combination tee with 3/4" FPT 4 1.90 7.60 Lowe's1 1/4" male pipe end 2 0.43 0.86 Dripworks BMP1141 1/4" hose clamps 10 0.75 7.50 Dripworks BSCH1 or BSCH112

1 1/4" PVC threaded cap 1 0.25 0.25 Lowe'sSubtotal 39.31

Distribution3/4" MPT x 3/4" MHT adapter 4 0.50 2.00 Dripworks AMHMP3/4" FHT x 3/4" barb 4 1.25 5.00 Dripworks CST343/4" clamps 4 0.50 2.00 Dripworks BSHC3/4" nipple (optional) 4 0.30 1.20 Lowe's3/4" threaded ball valve (optional) 4 2.5 10.00 Dripworks P34BVT3/4" poly tubing - price per foot 800 0.066 52.80 Dripworks 345003/4" compression hose ends with caps 4 0.66 2.64 Dripworks CETC34Subtotal 75.64

EmittersMini-wobbler - medium flow 28 2.75 77.00 Dripworks MWGMini-wobbler - riser with 3' tubing 28 1.18 33.04 Dripworks MWRA1/2" PVC Schedule 40 - 30 pieces cut from 10' pipe 10 1 10.00 Lowe'sSubtotal 120.04

Total Cost of field (Mainline, Distribution and Emitters) 234.99

Total Cost of system 921.54

Figure A - Pump and Media Filter

2" suction hose

Pump

2" discharge hose

Media Filter

PressureRegulator (50

PSI) 1 1/2" MPTinlet and 1 1/2"

MPT outlet

Media Filter Valve Assembly

three ports all are 1 1/2" FPT1) inlet from pump2) filtered water3) backflush water

plumb the backflushed water port the same asfiltered water port

1 1/2" PVCfemale adapter1 1/2" PVC pipe

(about 8" long)

2" PVC femaleadapter

PVC 2" x 1 1/2"reducer

1 1/2" PVC pipe1 1/2" PVC

elbow- 90 deg

2" male layflathose end with

barb (connectedwith clamp)

1 1/2" Maleadapter

1 1/2" PVC elbow- 90 deg

1 1/2"PVC pipe

1 1/2"femaleadapter

strainer

1 1/2" discharge hose

1 1/2" layflat male adapter withbarb (connected with clamp)

1 1/2" Layflat female hose endwith barb (connected with clamp)

Connections to pumpsvary - consider usingCam quick connect

fittings

Strongly suggestusing Cam quickconnect fittings

thisgoes

inhere

Port1

Port2

1 1/2" x 1 1/4"MPT adapter

1 1/4" threadedball valve

1 1/4" x 2" nipple

1 1/4" threadedunion (female

side)

1 1/2" PVC

1 1/2" triple "Y",slip fit

1 1/4" threadedunion (male side)

1 1/4" MPT x1 1/4" barb

secure with clamps

1 1/2" PVC

1 1/2" MaleAdapter

1 1/4" threadedunion (male side)

1 1/4" x 2" nipple

Pressure Regulator1 1/4" FPT inlet x

1" FPT outlet

1" MPT x1 1/4" slip

1 1/4" PVC

1 1/4" FPTadapter

1 1/4" x 2" nipple

1 1/4" threadedunion (female

side)

A

A

StandardFieldConnection

A

A

PressureRegulatorAssembly(insertedbefore

standardfield

connectionfor drip

irrigation

1 1/4" Flattube(mainline tubing)

1 1/4" MPT x1 1/4" barb

secure with clamps

1 1/4" threadedcap

1 1/4" threadedunion (male side)

1 1/4" x 6" nipple

1 1/4" threadedunion (female

side)

A

A

Fertilizer InjectorAssembly

(inserted afterPressure Regulator)

Holes drilled permanufacture's

directions

Figure B - Manifold Assembly

1 1/4"barb

1 1/4"barb

3/4"FPT

3/4 nipple

3/4 MPT x 3/4MHT adapter

3/4" FHT x3/4" barb

(secure withclamp)

3/4" threaded ballvalve

1 1/4" barb x 3/4" FPTcombination tee

(connected with clamps)

A

A

Can be omitted ifcapability to shut off

sub-main is notneeded

Figure C Mainline to Distribution Line for Mini-Wobbler

1 1/4" Flatube 1 1/4" Flatube

EZ-Gro hose bibfertilizer injectorcan be insertedhere to fertilizejust a sub-main

3/4" poly tubing

3/4" compression hoseend

hose cap(for flushing line)

1 1/4"barb

1 1/4"barb

3/4"FPT

3/4" nipple

3/4 MPT x 3/4MHT adapter

3/4" compressiontee with 3/4" FHT

3/4" threaded ballvalve

1 1/4" barb x 3/4" FPTcombination tee

(connected with clamps)

A

A

Can be omitted ifcapability to shut off

sub-main is notneeded

Figure D Mainline to Distribution Line for T-Tape

1 1/4" Flatube 1 1/4" Flatube

Push hose intofitting at least 1/2"

3/4" "figure 8"hose end

3/4" "figure 8"hose end

Tape-Loc with1/4" barb

T-Tape

T-Tape gripsleeve end

EZ-Gro hose bibfertilizer injectorcan be insertedhere to fertilizejust a sub-main

How much to irrigate

The following information was obtained from the internet and published by the North Carolina ExtensionService. If interested, you can view this information online by accessing urls:http://www.ces.ncsu.edu/depts/hort/hil/hil-33-e.html andhttp://www.extento.hawaii.edu/kbase/reports/dripirrigation.htm . Mountain Harvest Organics does not haveextensive experience in irrigation to know if this information is accurate. This information is supplied for yourconvenience.

Water Capacity for soils

Available water holding capacity is about 1 inch per foot for sandy soils and about 1.5-2 inches per foot forheavier soils. The fraction of water taken by the plant then depends on the root volume and on the soil waterholding capacity (leaching faster on sandy soils and remaining longer in heavier sandy loams or clay loams).Irrigations are usually scheduled when 50% of the available soil water has been depleted, with exact levelsdepending on the particular crop.

To continue with our example with tomato on 6 foot center beds, what would be the allowable water depletionfrom the soil between irrigations? Lets assume that these are young tomatoes with an effective root zone 10inches deep, and that the soil water capacity is 1.5 inches per foot.

The irrigated soil volume is:( 10 inches or 0.85 ft root zone)*(2.5 ft wide wetted zone)*(7260 feet per acre) = 15,064 cubic feet per acre

The amount of water stored in this irrigate soil volume (1.5 inches per foot= ca 13%) is:(0.13)*(15,064 cubic feet per acre)*(7.48 gallons per cubit foot of water) = 14,648 gallons per acre

Irrigations should then be conducted, at say, 50% allowable depletion, that is:(0.50)*(14,648 gallons) = 7,324 gallons

Chapter

5

When to irrigate

From our example with tomatoes on 6 foot centers we now know that our total irrigation demand for the cropcycle are 203,280 gallons per Acre. We also determined that at a growth stage when root depth is 10 inchesirrigations are recommended at 50% of allowable depletion (7,324 gallons). Water budgets are utilized todetermine when to irrigate next. A formula is used to determine the current levels of available soil water.Current soil water content= (the previous level) + (effective rainfall) + (irrigation water) - (cropevapotranspiration (ET)). ET may be expressed as acre inches or as gallons per irrigated plot. Following withour example, if daily ET = 0.10 inches per day per acre then

Daily irrigation requirement (ET)= (0.10 inches)*(27,152 gallons per acre-inch)= = 2715 gallons per acre.

We determined below that 50% allowable depletion occurs at 7,324 gallons per acre. Therefore we should beable to irrigate every 2-3 days. After 2 days the water levels lost through ET would be 37% of allowabledepletion and 56% after 3 days.

ET rates which range from < 0.10 during the winter to over 0.15 inches/day during the summer, can beestimated by using an open pan or may also be available from your local county extension office. Dr. I.P. Wu atUHM has developed a simple evaporation pan which would be of practical use to local producers.

Irrigation requirements by crop

Vegetable Irrigation Needs, Critical Moisture Periods, Drought Tolerance, Rooting Depth, and Concerns.

Preferred Minimum Soil Moisture

Crop Bars ASM1Amount in

inches / in "x"days

Irrigation Critical MoisturePeriod

PreferredIrrigationMethod2

Asparagus -.70 40% 1/20 Crown set and transplanting a,b

Beans, dry -.45 50% 1/7 Flowering a

Beans, lima -.45 50% 1/7 Flowering a,b

Beans, pole -.34 60% 1/5 Flowering a

Beans, snap -.45 50% 1/7 Flowering a

Beans, soy (edible) -.70 40% 1/14 Flowering a,b

Beet -2.00 20% 1/14 Root expansion a,b

Vegetable Irrigation Needs, Critical Moisture Periods, Drought Tolerance, Rooting Depth, and Concerns.

Preferred Minimum Soil Moisture

Crop Bars ASM1Amount in

inches / in "x"days

Irrigation Critical MoisturePeriod

PreferredIrrigationMethod2

Broccoli -.25 70% 1/5 Head development a,b,c

Brussels sprout -.25 70% 1/5 Sprout formation a,b,c

Cabbage -.34 60% 1/10 Head development a,b

Carrot -.45 50% 1/21 Seed germination, rootexpansion a,b

Cantaloupe -.34 60% 1/10 Flowering and fruitdevelopment a,b

Cauliflower -.34 60% 1/5 Head development a,b,c

Celery -.25 70% 1/5 Continuous a,b,c,d

Chinese cabbage -.25 70% 1/5 Continuous a,c

Collards -.45 50% 1/14 Continuous a,b,c

Corn, sweet -.45 50% 1/14 Silking a,b

Cucumber, pickles -.45 50% 1/7 Flowering and fruiting a,b,c

Cucumber, slicer -.45 50% 1/7 Flowering and fruiting a,b,c

Eggplant -.45 50% 1/7 Flowering and fruiting a,b,c

Greens (turnip, mustard,kale) -.25 70% 1/7 Continuous a,b

Leek -.25 70% 1/5 Continuous a,b

Lettuce (head, Bibb,leaf, cos) -.34 60% 1/7 Head expansion a,b

New Zealand Spinach -.25 70% 1/5 Continuous a,b,d

Okra -.70 40% 1/14 Flowering a,c

Onion -.25 70% 1/7 Bulbing and bulb expansion a,b

Parsnip -.70 40% 1/14 Root expansion a,b

Peas, green -.70 40% 1/7 Flowering a

Peas, Southern -.70 40% 1/14 Flowering and pod swelling a,b

Peppers -.45 50% 1/7 Transplanting flower up to 1/2"fruit a,b,c

Vegetable Irrigation Needs, Critical Moisture Periods, Drought Tolerance, Rooting Depth, and Concerns.

Preferred Minimum Soil Moisture

Crop Bars ASM1Amount in

inches / in "x"days

Irrigation Critical MoisturePeriod

PreferredIrrigationMethod2

Potato, Irish -.35 70% 1/7 After flowering a,b

Pumpkin -.70 40% 1/14 Fruiting a,b

Radish -.25 70% 1/5 Continuous a

Rhubarb -2.00 20% 1/21 Leaf emergence a,b

Rutabagas -.45 50% 1/14 Root expansion a,b

Squash, summer -.25 70% 1/5 Fruit sizing a,c

Squash, winter -.70 40% 1/10 Fruit sizing a,b

Sweetpotato -2.00 20% 1/21 Fruit and last 40 days a,b

Tomato, staked -.45 50% 1/5 Fruit expansion a,c

Tomato, ground -.45 50% 1/7 Fruit expansion a,b

Tomato, processing -.45 50% 1/7 Fruit expansion a,b

Turnip -.45 50% 1/10 Root expansion a,b

Watermelon -2.00 40% 1/21 Fruit expansion a,b,c

1 ASM (Available Soil Moisture). % of soil water between field capacity (-0.1 bar) and permanent wilting point (-15 bars).2 Irrigation method: a=Sprinkler, b=Big Gun, c=Trickle, d=Flood

Vegetable Irrigation Needs, Critical Moisture Periods, Drought Tolerance, Rooting Depth, and Concerns

Crop DroughtTolerance3

RootingDepth4

Defects Caused by WaterDeficit Comments

Asparagus H D Shriveling Will withstand most drought

Beans, dry M M Poor pod fill & small beans No irrigation after pods begin to dry

Beans, lima L-M D Poor pod fill & small beans Cooling irrigation can increase yield

Beans, pole L-M M Poor pod fill & pithy pods Steady moisture supply is necessaryduring flowering

Beans, snap L-M M Poor pod fill & pithy pod Irrigation prior to flowering has littlebenefit

Beans, soy (edible) M M Poor pod fill Irrigation prior to flowering has littlebenefit

Beet M M Growth cracks

Broccoli L S Strong flavor

Brussels sprout M S Poor sprout production

Cabbage M-H S Growth cracks

Carrot M-H S-M Growth cracks, misshapen roots Avoid droughts during rootexpansion

Cantaloupe M S-M

Cauliflower L S Ricey curd, buttoning

Celery L S Small petioles Moisture deficit can stop growthirreversibly

Chinese cabbage L S Tough leaves

Collards M S Tough leaves

Corn, sweet M-H S Poor ear fill Irrigation prior to silking has littlevalue

Cucumber, pickles L S-M Pointed & cracked fruit Moisture deficit can drasticallyreduce yield and quality

Cucumber, slicer L S-M Pointed & cracked fruit Moisture deficit can drasticallyreduce yield and quality

Vegetable Irrigation Needs, Critical Moisture Periods, Drought Tolerance, Rooting Depth, and Concerns

Crop DroughtTolerance3

RootingDepth4

Defects Caused by WaterDeficit Comments

Eggplant M M Blossom-end rot, misshapen fruit

Greens (turnip,mustard, kale) L M Tough leaves Good continuous moisture essential

to good yields

Leek L-M S Thin scale formation

Lettuce (head, Bibb,leaf, cos) M-H D Tough small leaves

New Zealand Spinach L S Tough leaves, poor production Irrigate to keep growth continuousand rapid

Okra M-H D Tough pods Irrigation can reduce yield

Onion L S Poor size

Parsnip H D

Peas, green L M Poor pod fill

Peas, Southern M M Poor pod fill Plants will recover from drought butyield is reduced

Peppers M M Shriveled pods, blossom-end rot Irrigate for increased pod size andyield

Potato, Irish M S Second growth & misshapenroots

Irrigate only during extreme droughtduring root development

Pumpkin M D Blossom-end rot

Radish L S Pithy roots Keep soil moisture levels high topromote rapid growth

Rhubarb M D Pithy stems

Rutabagas M M Tough roots

Squash, summer L M Pointed & misshapen fruit Fruit sizingIrrigation can double ortriple yields

Squash, winter M D

Sweet potato H D Small & misshapen roots

Tomato, trellis M D Blossom & root growth cracksContinuous water supply helps avoidblossom-end rot and increase fruitsize

Vegetable Irrigation Needs, Critical Moisture Periods, Drought Tolerance, Rooting Depth, and Concerns

Crop DroughtTolerance3

RootingDepth4

Defects Caused by WaterDeficit Comments

Tomato, ground M D Blossom & root growth cracks

Continuous water supply helps avoidblossom-end rot and increase fruitsize

Tomato, processing M D Blossom & root growth cracksContinuous water supply helps avoidblossom-end rot and increase fruitsize

Turnip M M Woody roots

Watermelon MH D Blossom end rotThis crop can withstand extremedrought, but there will be some yieldreduction

3 Drought tolerance: L = low, needs frequent irrigation; M = moderate, needs irrigation in most years; H = high, seldomneeds irrigation.4 Depth of rooting, of most roots: S = shallow, 12 to 18 inches; M = moderate, 18 to 24 inches; D = deep, 24 inches plus.

Helpful Hints

• Use valves that don’t reduce the water flow. For instance, the typical faucet hose bibs tend to reduceflow, whereas shut-off PVC ball valves won’t reduce water flow.

• Size your distribution lines so that if you needed to repair them by adding a coupler and connectingline sections together, you would still have adequate water flow.

• When testing your irrigation system, typically you leave the discharge hose connected to the pump,however if the discharge hose is full of water, it may create a situation where your pump won’t primebecause there is too much pressure on the pump for the suction valve to open.

• The pump water intake can typically handle a 25’ or less elevation gain. If you find your pump isn’tpumping water, verify that your pump intake is 25’ or less from the pump.

• When trying to pump water up hill or at a greater distance, you may need to reduce your pumpoutput hose, thus reducing the water weight being pushed up hill. When sizing your pump, look athead and feet limitations, comparing it to your requirements.

• Consider having a _” threaded end cap on your main and field distribution lines. This allows fortrouble-shooting pressure problems by attaching a pressure gauge. In addition, the end cap providesthe capability to flush the lines preventing debris from clogging the line.

• If irrigating with mini-wobblers and pumping from a water source that has debris, you may be ableto avoid using a filter by placing your pump suction hose in a bucket, then placing the bucket andsuction hose in the stream. This will help to prevent the suction of debris that may clog the mini-wobblers.

• If you have a water source that other than a pump, you may be able to use a timer to automateirrigation.

• The mainline should be selected one class higher than that specified for the operating pressure. Thiswill cater for the extra pressure caused by water hammer.

• It is recommended that you provide a means for measuring the water pressure coming out of yourfilter(s) to help in knowing when the filter needs cleaning/backflushing.

Chapter

6

• When sizing your filter, the filter mesh orifices should be at least one quarter of the micro-sprinklersoutlets or one seventh of the emitters’ outlets.

• When designing your irrigation system and using fertilizer injectors, be sure not to install the fertilizerinjector before the filter as this could cause your fertilizer to be filtered from the system. In addition,be careful on the fertilizer used in that it does not have particles that will clog the line.

• When irrigating from a creek or branch with a pump, be sure to chain your pump to a tree toprevent the pump from being washed away during high waters or from vibrating and falling into thewater.

• When irrigating from the creek or branch, your pump may suck up gravel which can wear down thepump impeller so cover your suction hose with fine mesh or mesh.

• 22,000 gallons of water provide an acre inch

Resources

Suppliers

Mountain Harvest Organics does not have extensive dealings with many of the suppliers listed. Your feedbackto Mountain Harvest Organics in reviewing these suppliers is appreciated to maintain a comprehensive list ofrecommended suppliers.

• Dripworks – Their contact numbers are as follows: catalog request line 800-616-8321, order line 800-522-3747, design and technical support 707-459-6323, fax 707-459-9645, or on the web athttp://www.dripworksusa.com . We mostly dealt with this supplier who was very helpful in answeringquestions and helping to choose the right components for the right situation.

• DIG Irrigation Products - Their contact numbers are as follows: customer servce 800-344 -1172, Fax760-727-0282, or on the web at http://www.digcorp.com/asdig/diy/Ahome.htm .

• The Drip Store –Their contact numbers are as follows: orders 760-735-3225, fax 760-735-3255 or on theweb at http://www.dripirrigation.com/ . Their web site is full of great information so use them as a resource.

• The Wade Rain –Their contact numbers are as follows: customer service 503-692-5353, fax 503-692-5358 or on the web at http://www.waderain.com/contact.html .

• PlumbingWarehouse.com – Their contact numbers are as follows: fax 530-891-0654, or on the web athttp://www.plumbingwarehouse.com/welcome.html . I do not have a phone number for a human as

• Netafim Irrigation Inc. – Their contact numbers are as follows: customer service toll-free 888-638-2346,or 559-453-6800, fax 559-453-6803 fax 530-891-0654, or on the web athttp://www.netafim.com/netafim/doa_iis.dll/Serve/item/English/1.4.3.1.66.html .

• Aquatic Creations – They specialize in pond supplies. Their contact numbers are as follows: customerservice 877-766-3347 or 630-761-8300, fax 630-761-8300 or on the web athttp://www.pondbuilder.com/index.htm .

• Rain Bird –Their contact numbers are as follows: customer service 626-963-9311, fax 630-761-8300 oron the web at http://rainbird.com/index.htm .

Chapter

7

• Water Rite Products –Their contact numbers are as follows: customer service 800-871-3747, fax 916-925-4035 or on the web at http://www.waterrite.com/ .

• DRIPS Plumbing and Water Supplies –Their contact numbers are as follows: customer service 877-503-7477 or 520-775-6760, fax 520-775-2725 or on the web at http://www.dripssupply.com/ .

Design/Implementation Information

Many of the suppliers listed provide helpful information on the web or you may call them and talk with atechnical representative. These are a few resources for designing a micro irrigation system.

• Arizona Cooperative Extension – Micro irrigation design guidelines who can be found on the web athttp://ag.arizona.edu/pubs/garden/mg/irrigation/Design.html .

• NebGuide – Micro irrigation design guidelines who can be found on the web athttp://www.ianr.unl.edu/pubs/irrigation/g525.htm .

• GeoFlow – Micro irrigation design guidelines who can be found on the web athttp://www.geoflow.com/agriculture/factors.htm .

• Irrigation Association of Australia – Micro irrigation design guidelines who can be found on the web athttp://www.agric.wa.gov.au/agency/pubns/farmnote/1992/F03092.htm .

• Michigan State University – Micro irrigation design guidelines who can be found on the web athttp://www.landscape.org/Landsculptor/00-03/03-00irrigation.html .

Glossary

Adapters and fittings – Generic term for components are used to connect the mainline, sub-main and fielddistribution lines. In addition, they are used to attach emitters to field distribution lines. Typically a barb fittingis used to connect the drip tubing to the sub-main or mainline. The barb fitting can vary in size which affectsthe volume of water that can flow through it. The combination of the barb and drip tape must be matched tothe drip tape run length.

Acre Foot (also acre feed) – A measurement of water quantity most often used in agriculture. The amount ofwater needed to cover one acre of area with water one foot deep.

Acre Inch – A measurement of water quantity most often used in agriculture. The amount of water needed tocover one acre of area with water one inch deep.

Backflow Preventer – A backflow preventer prevents water from being sucked back into the water sourceshould a reverse flow situation occur and is needed when your water source is either a house well or city welland you are using fertilizer and/or pesticide injectors. In most places backflow preventers are required by lawon all irrigation systems.

Barb – A piece of tubing with a tapered end and a raised ridge which is inserted into another piece of tubing.

Barb Punch – A tool used for making a hole in the tube specifically for inserting a barb. The correct sizing ofthe barb hole is critical to prevent excessive water leakage.

Ball Valve – This type of valve controls the water by means of a rotating ball with a hole through the center ofit. When the hole is aligned with the water flow, the water flows freely through the valve with almost nofriction loss. When the ball is rotated so that the hole is not aligned, the flow is completely shut off. Ball valvesare used primarily as isolation valves or as a means for a shut-off valve without the water flow restriction that atypical hose bib may have. They tend to be very reliable and trouble-free.

Bushing – A bushing is a small piece used to connect two pipes of different sizes together. A standardreducer bushing has one male end (for the larger pipe) and one female connection (for the smaller pipe).

Booster Pump – A device to increase the water pressure is a system where some pressure already exists.For example, if water comes from your water source at 40 PSI of pressure but you need 80 PSI ofpressure for the irrigation system, you would use a booster pump to increase the pressure.

Coupling – A fitting used to join two sections of pipe together.

Controller – A "timer" used to turn on and off an automatic irrigation system. Controllers range fromvery simple to extremely sophisticated computer systems that utilize modems and 2-way communicationbetween the controller and the units (valves, meters, weather stations, soil moisture sensors, etc.) beingcontrolled.

Cubic Feet – A measurement of water quantity, often used by water companies in the United States ofAmerica to measure water use by customers. A cubic foot is one foot in length, one foot in width, and one footdeep (Duh).

Cubic Meters – A metric measurement of water quantity, often used by water companies to measure wateruse by customers. A cubic meter is one meter in length, one meter in width, and one meter deep (right, like Ireally needed to tell you that!).

Drip Tubing – Drip tubing is a thin wall polyethylene tube and can vary on the diameter of the tube, thespacing of the emitters, and the flow of water emitted. The most common size that we have seen is 5/8”. Themanufacture of the drip tubing should provide you with maximum lengths that the drip hose can run from thewater entry point. For example, some drip hose may not exceed 200’ from the point the water enters the tubeto the end of the tube. If you were to install the water entry point in the middle of the tube, you could get 400’of tube.

Ell – A fitting used to change the direction of a pipe. Available in 90 degree and 45 degree bends. Somespecialty ells are available in other angles but have limited availability. You can remember ells simply by theirshape, they look like an "L". Ells are available with threads in both ends, threads in one end and a slip fit socketin the other, or with two slip fit sockets at each end.

Emitters – A small device that controls the flow of water going to the soil. Emitters come in many differentflow rates and styles. Most emitters emit 4 liters/hour (4,0/hr) of water or about 1 gallon per hour (GPH). It isrecommended that pressure-compensating emitters be used in hilly areas. The pressure compensating emittersnormally don’t work well under 10 PSI so this should be a factor when choosing your emitters. Whendetermining the types of emitters to be used, take into consideration the area to be irrigated because the highervolume emitters may not support a large area. Multi-outlet emitters are available but have known to be moretroublesome so avoid if you desire a trouble-free drip system.

End Caps – This prevents water from running out the end of the mainline, sub-main or field distribution lines.Consider using a _” threaded end cap for the mainline, sub-main and field distribution lines because they allowyou to attach of a pressure gauge when trouble shooting problems with your drip irrigation system. In addition,they easily allow you to flush the system.

Female Adapter – The fitting used to adapt from solvent welded PVC to a threaded connection. Never, everuse a plastic female adapter on anything with metal threads. Never tighten a female adapter with a wrench, handtighten it only! The female adapter will split if you over tighten it. In plumbing, male parts always fit into femaleparts (just in case you hadn't already figured that out) .

Field Distribution Lines – The distribution line that contains emitters or drip holes to distribute water to thefield and is connected to either the mainline or sub-main distribution lines. Drip Tape can be considered a“field distribution line” since it distributes water to the field. In addition, mini-wobblers can also be connectedto the field distribution lines since they too deliver water to the field.

Filter – Drip emitters have very small openings and are easily clogged. In addition, city water is not free fromforeign matter that will clog your emitters. Use at least a 150 mesh screen or one with a higher mesh numberlike 200. Inexpensive plastic filters often sold for drip systems should be installed after the pressure regulator,other filters may be installed before the valve or pressure regulator. A top quality filter can be installed rightafter the water source so it protects the valves and pressure regulator. Use a filter that is the same size as, orlarger than the valve. It is recommended that you provide a means for measuring the water pressure coming outof your filter which will help in knowing when the filter needs cleaning/backflushing.

Flushing - Flush valves should be installed to allow a drip irrigation system to be flushed periodically duringthe season. Flush valves should be installed at the end of each mainline and lateral. During this draining process,

accumulated precipitates and particulate matter are discharged from the tube. This valve can either be manualor automatic. Automatic flush valves automatically flush laterals at each irrigation. Most automatic flush valvesare open when there is low pressure in the laterals but close when the pressure exceeds 1 or 2 psi. This meansthat a small amount of water is flushed through the valves as the pressure builds up. Manual flush valves arealso available and can be either spring-loaded, a threaded cap, a crimped tube or other manual valve. For somesystems, the ends of the laterals can be folded back on themselves using a short piece of drip irrigation tubing asa sleeve to hold the crimp in place. Removing this sleeve allows the lateral to be flushed manually.

GPM – Abbreviation used by irrigation designers when they are too lazy to write "gallons per minute".

Gravity Flow – The term given a water system that relies on gravity to provide the pressure required todeliver the water. Consists of a water source located at a higher elevation than the water delivery points

Goof Plugs - A barb that is capped and may be inserted into a barb hole that allows you to stop an existingbarb hole.

Male Adapter - The fitting used to adapt from solvent weld PVC to a male threaded end. Whenconnecting to metal threads male adapters should be used, so that the plastic male threads screw into themetal female threads. It may seem sexist, but PVC plastic male adapters work better than PVC plasticfemale adapters.

Mainline Distribution Lines – The distribution line that goes from the water source to control valves.Typically the main distribution line is a larger pipe size than the sub-main distribution lines. The sampleconfigurations included with this manual consist of a 1 _” mainline. When sizing your mainline pipe, considerthat you may need to repair line breaks, therefore size so if a coupler is needed the minimum water throughputwill still be able to carry enough water to your sub-main and field distribution lines.

Mini-Wobblers – A type of micro overhead irrigation. These may be a more economical way to irrigate agiven area than with drip tape, especially if it is important that the entire seed bed be irrigated.

Nipple – The common plumbing term used in the irrigation trade for a short length of pipe, usuallythreaded on both ends. Another of many overly descriptive terms used in the plumbing trade.

Nozzle – The part of a sprinkler that the water comes out of and is normally very carefully engineered toassure a good spray pattern. In most cases the nozzle is removable so that it can be easily cleaned orreplaced.

Polyethylene – A plastic used for manufacturing irrigation tubing. "Poly" for short. Poly pipe is almostalways black in color, sometimes with a strip of a different color for identification. It is very flexible, andis usually sold in coils of 100 feet or more of tube. Poly pipe is often used in areas where the groundfreezes 12" deep or more, and also in mountainous areas that are extremely rocky. Poly pipe uses inserttype fittings where a barbed shank is shoved into the end of the tubing. These fittings must be clamped,the barbs alone will not hole the tube on the fitting. Also see "PVC" for the most commonly used pipematerial.

Precipitation Rate – A measurement of water application. The measurement is given in the depth of waterapplied to the soil. In other words the depth that the water would be if it didn't run-off or soak into the soil. Inthe USA precipitation rate is measured in inches per hour. In metric countries it is measured in millimeters perhour.

Pressure Gauge – A device used to measure water pressure. Used for knowing the water pressure at variouspoints in your micro irrigation system. Typically you can purchase a gauge that will screw into a regular _” hoseend. When designing your system, be sure to include points of entry for testing the water pressure. Forinstance, be sure to have the capability to screw in a pressure gauge at the end of your mainline and fielddistribution lines for monitoring pressure. It is recommended that you provide a means for measuring thewater pressure coming out of your filter which will help in knowing when the filter needscleaning/backflushing.

Pressure Head - Measurement of water pressure based on the water depth. Measurement is stated as "feet ofhead" or "meters of head". One foot of head is the pressure at the bottom of a 1 foot high column of water,which is also equal to 0.433 PSI. So it's really a measure of the weight of water of a given depth. It doesn'tmatter how much water is present, the pressure head is only determined by the depth of the water. The waterpressure at the bottom of a 2" diameter, 20 foot tall water filled pipe is the same as the water pressure at thebottom of a 20 foot deep lake.

Pressure Loss - The term given for the loss of energy, in the form of pressure, that occurs whenever watermoves through a pipe or any other piece of irrigation equipment. Pressure loss also occurs when water movesuphill against the force of gravity. If the total pressure loss in a piping system exceeds the available static waterpressure the water will not flow. In landscape irrigation systems no flow means no grow.

Pressure Regulator – Most drip systems require a pressure regulator because the emitters or drip tape requirelower pressure than what the pressure from your water source. If in doubt, install one to prevent damagingyour micro irrigation equipment. Typically you will need a pressure regulator if your water pressure to yourdistribution lines is more than 40 PSI.

Pump – A device which increases the water pressure or moves water from your water source to your mainline.Depending on the size of foreign matter in your water supply, you may need a filter. In addition, depending onthe volume of water your pump will move, you may need a pressure regulator.

PVC - Abbreviation for poly-vinyl-chloride. A type of plastic used to make water pipe. Usually white in colorbut sometimes is gray or purple. Purple is normally used for “reclaimed” water.

Sub-Main Distribution Lines– The distribution line that goes from the mainline to the connection point offield distribution lines. When sizing your sub-main pipe, consider that you may need to repair line breaks,therefore size so if a coupler is needed, the minimum water throughput will still be able to carry enough waterto support your field distribution lines. In the sample configurations included in this document, typically a sub-main is used when multiple drip tubes are needed.

Tee – A fitting shaped like a “T” and used to branch a side pipe off of a pipeline. A related fitting is the"Y" which is used primarily for sewer pipelines not sprinklers.

Tensiometer – A tool used for monitoring soil moisture down in the root zone and can provide a simplemeans for determining irrigation schedules. Typically, two tensiometers are used per irrigation block, oneat 12-inch and the second at 6-inch soil depth. A tensiometer reading of 0 indicates soil water saturation.As an example, the drip system is turned on when the 12-inch tensiometer reads 20 to 30, and thenturned off when the 6-inch one reads 10 or below.

Unions – Connectors, in our design they are made of PVC, and allow the grower to connect the mainline orsub-main to long lines such as drip tape.

Valve - Valves can be automatic or manual. If you use an anti-siphon valve it has a built-in backflow preventerwhich saves money! (But be sure to read up on backflow preventers first as anti-siphon valves won't work insome places. See also ball valve.

Stakes – It is recommended that your tube be staked every 3’. We use high tensile wire for our stakes and donot put them every 3’ because we have way too many rocks in our fields which makes it difficult to get a stakein the ground!!!

Barbs – See adapters and fittings.