Hop Irrigation Drip Line Planning

Hop Irrigation Drip Line Planning


Hop Yard Irrigation

Planning Your Drip Lines and Zones

We will now use our water supply knowledge and apply it to a Drip Line layout.  For this discussion we will assume a flow rate of 400 gph, and pressure of 60 PSI.

The Hop Yard we will use for this example will be 15 Rows of 250 ft each.  Each row will be 16 feet apart.  The water supply will be located 100 feet from the start of the Hop Yard.  Hops will be planted 3 feet apart.  We will now go through the steps to determine a zone layout that will provide an effective Drip Watering system.

Step 1: Calculate Number of Hops and Water Needed - In this example we will have 1,250 Hops to water (15 Rows with 83 Hops per Row).  In their second year Hops can require up to 16 gal (60 Litres) per plant per week.  Total consumption for the Hop Yard will be up to 20,000 gallons per week, or approximately 2,850 gallons per day.  This of course does not take into account natural rain fall, which can take care of much of the watering needs, but you must be prepared for dry spells and thus take the worst case scenario into account.      

Step 2: Calculate Water Use Per Row and Choose Emitter Flow Rate - Choosing an emitter flow rate is one of the most critical components for planning an effective Drip Irrigation System. The decision will determine the number of rows you can water at one time while also impacting the time it takes to effectively water the entire Hop Yard.  There are a few factors to take into account when choosing an emitter.  The primary factor is water source available, with the others being desired time to water and soil type.

In this example we have 83 plants per row to water.  The higher the output of emitter we choose the less time it will take to water the row.  Take for example a day where you would like to give each plant 2 gallons (7.5 Litres) of water.  This would require 166 Gallons Per Row.

Emitter Ouput 1/2 GPH 1 GPH 2 GPH
Time To Water One Row (Hours) 4 Hours 2 Hour 1 Hour
Consumption Rate Per Row (GPH) 41.5 GPH 83 GPH 166 GPH
Maximum Number of Rows (400 GPH Available) 9** 4 2
Recommended Maximum Rows (75% = 300 GPH) 7 3 1

**Maximum Number of Rows Calculated as 400 GPH ÷ Consumption (for 1/2 GPH Emitter) 41.5 GPH = 9.63 approx. 9

As you can see as the Emitter output goes up the time to water goes down, and at the same time the number of rows that can be watered at any one time goes down.  We have found most customers have chosen a lower emitter rate to increase the number of rows that can be watered at one time with 1/2 GPH being our most popular.  For pressure compensated drip emitters the lowest available output is 1/2 GPH, however emitters available in Drip Emitter tubing are offered as low as .26 GPH.  

Step 3: Planning Your Zone Layout - When deciding on a zone layout for Drip Irrigation systems we always recommend to be conservative when planning your zone layout.  Having more zones serves a few purposes; firstly it will ensure the zone has adaquate water supply to feed the emitters, and secondly provides more control over the entire system if for instance one zone has been harvested and needs to be shut off from the rest of the system.  

For this illustration we have 15 rows in our Drip System with a recommended maximum of 7 rows using 1/2 gph emitters.  Rather than having 2 zones of 7 rows and 1 zone with one row, we would likely split the yard into 3 zones of 5 rows each.  This will ensure adequate water flow for each zone and split the watering system into thirds.  That being said there is nothing wrong with dividing the yard up into smaller zones to provide more control.  This is often done when different varities of plants are grown in the same yard, when one may require a different watering schedule than the other.  

For this example we will continue with 3 zones of 5 rows each and now we can start to put the system together.

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