Effects of Subsurface Micro-irrigation on Water Use Efficiency and Hazelnut Tree Growth

Final report for FW19-351

Project Type: Farmer/Rancher
Funds awarded in 2019: $19,767.00
Projected End Date: 06/30/2022
Host Institution Award ID: G237-19-W7501
Grant Recipient: ZD Farms of Oregon
Region: Western
State: Oregon
Principal Investigator:
Darrel Smith
ZD Farms of Oregon
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Project Information


Effects of Subsurface Micro-irrigation on Water Use Efficiency and Hazelnut Tree Growth

Moisture losses associated with surface evaporation and weed growth under conventional surface irrigation methods, support research of highly efficient irrigation methods for producers to better conserve water and increase production efficiency. Drip irrigation is the most efficient method of irrigation but also has issues when used in orchards; tripping on the exposed lines, damage to the system from exposure to sunlight and rodents, concerns regarding the effectiveness of delivery of water and nutrients to the roots, and issues with plugged or non-flowing emitters that go undetected.  Subsurface Drip Irrigation (SDI) puts the emitters underground eliminating issues with surface drip systems and micro-emitters. Benefits of SDI include the highest water use efficiency of any irrigation method reducing water use up to 40% while increasing yields and quality.

This project has three objectives: 1) determine the value of subsurface micro-irrigation on hazelnut tree growth; 2) define the best and most effective use of available irrigation systems for orchard crops; and, 3) evaluate the costs associated and best practices for greatest efficiency in water use for hazelnut growers. 

This study, an extension of a previously funded SARE project, will clarify the advantages of this new irrigation method for growers coping with water scarcity in the western U.S., and gain a better understanding of growth capacities of hazelnut trees under water stress. The project will take place on a 13.4-acre hazelnut growing operation in the northern Willamette Valley of Oregon where 1,100 hazelnut trees have been planted in the last 4-years.

Education and outreach will include field days (pre- and post-harvest), irrigation in orchards “How-To” guide that will be distributed for free to orchardists in the region, articles in trade publications, and sharing the research results via social media outlets.

Project Objectives:

Overall goal: Achieve comprehensive understanding of subsurface micro-irrigation on hazelnut tree growth and hazelnut quality using minimal amounts of water to achieve acceptable nut quality.

Obj 1: Evaluate efficiency of our subsurface micro-irrigation strategy on water conservation

  • Sub-obj 1: Calculate water saved without diminishing nut quality [Oct. – Dec. 2019/2021]
  • Sub-obj 2: Compare different water use efficiency between subsurface micro-irrigation methods and surface drip irrigation [Oct – Dec. 2019/2021]
  • Sub-obj 3: Determine combinations of water delivery amount and irrigation depth yielding highest water use efficiency [Oct – Nov. 2019/2021]


Obj 2: Measure the impact of our new subsurface micro-irrigation strategy on hazelnut growth and nut quality

  • Sub-obj 1: Assess role of subsurface micro-irrigation strategies in hazelnuts quality [Mar.– Nov. 2019/2021]
  • Sub-obj 2: Quantify subsurface micro-irrigation effects on hazelnut root distribution [Apr. – Nov. 2019/2021]
  • Sub-obj 3: Analyze nutrient content in hazelnuts [Oct. – Mar. 2019/2021]


Obj 3: Educate hazelnut producers and engage community members on irrigation water conservation and hazelnut quality improvement

  1. Sub-obj 1: Conduct workshops to educate producers about improving hazelnut quality by using less irrigation water [Feb. & Aug. 2019/2021]
  • Sub-obj 2: Develop educational materials for orchard managers and hazelnut growers to conserve irrigation water and improve water use efficiency [Jan. 2019 – Apr. 2021]

Research Timetable for Project:


Research timetable of proposed milestone events during funding years:






















Objective 1

Conduct Survey

Assess Problem Scope 

Identify study sites



One Time



















Objective 2 –

Remote Sensing


Assess tree water stress by three methods


As needed











































Objective 3 –

Apply supplemental irrigation treatments

Install in 2020 -

As needed





Objective 4 –

Obtain nut yields among treatments

At harvest












Objective 5 -

Present results at annual meetings

Year-long and by Events





Publish in peer journal



















Click linked name(s) to expand/collapse or show everyone's info
  • Prof. Pete Jacoby (Researcher)


Materials and methods:

Because irrigation practices and their impact on growing operations and management practices are a result of many factors including seasonal and annual weather pattern changes, various irrigation methods may have simultaneous benefits and disadvantages, and measurements can’t be completed in a short study. Single year results do not provide an adequate evaluation of a cover crop’s potential (UC Davis Publication 3338). That is why multiple year experiments such as the one we are proposing are important to find out what works best with a given farm, its microclimate, soils, set of equipment, and other factors. In the case of long-term irrigation methods of hazelnut trees, benefits of each irrigation method may take several years to become apparent. For this project, education and outreach will include field days (pre- and post-harvest), irrigation in orchards “How-To” guide that will be distributed for free to orchardists in the region, articles in trade publications, and sharing the research results via social media outlets.

The project will take place on a 13.4-acre hazelnut growing operation on ZD Farms of Oregon in the northern Willamette Valley of Oregon where 1,100 hazelnut trees have been planted in the last 4-years.  The orchard is broken into 5 irrigation zones of hazelnut trees ranging from 129 trees to 324 trees and ranging in age from 3-years to 4-years.  The orchard has standard drip micro-irrigation systems supplying each tree with a single emitter and with drip supply tubing surface distributed.  The project will include comparison of SDI and vertical watering pipes to existing drip system in the field designated Field 2 where 154 trees of the oldest variety are available and growing in the same soil type.  4 rows from this field, each with 27 trees will be selected, prescreened and 1 each row setup with SDI micro-irrigation, with 2 vertical pipe emitters per tree, with 3 vertical pipe emitters per tree and a control row with the existing drip system.  Evaluation will be made on a quarterly basis for relative tree growth as well as core samples made for water displacement characteristics at the root level for each irrigation type.  This layout of trees and irrigation variations allows for the various systems to utilize the same water source and soil type leaving the key variables to be in the irrigation methods allowing for more efficient project management and monitoring. There is also good vehicle access, plenty of parking, and field accessibility for our educational field days.

Update 2021;

As of this writing, the main headers have been installed, the sub-lines feeding the rows have been installed and each control or test tree has been setup as intended.  There are 2 control rows, two PVC subsurface rows and 2 manufactured sub-surface drip rows setup.  The field is an irregular shape and therefore the number of trees in test for each type, control or deep drip option varies and is outlined in the following table;

Row Designation Irrigation Type Trees Per Row
B Control - Surface Drip 25
C PVC Deep Drip 23
D DRI Deep Drip 20
E Control - Surface Drip 20
F PVC Deep Drip 17
G DRI Deep Drip 11

Table: Irrigation Type per Row Per Number of Trees in the Test

In summary there are 45 trees considered control trees using the common surface drip method. 

There are 40 trees that utilize a 2 drip/tree PVC system for deep drip.  

There are 31 trees that utilize the deep drip system from DRI.

Notes on the system setup:

  • In all rows, the same drip emitter was used for the control, the PVC deep drip system and the DRI deep drip system.
  • In each row, the feed system has been setup separate so each row can be not only controlled independently but also can be monitored through the use of flow meters on each row.
  • The flow meters are recorded at the beginning of the season, throughout the season and at the end of the growing season to give a total amount of water provided as well as the calculation for water per tree per season.
  • All rows are fed by a common header line that is charged (filled) prior to opening the row feed valve to initiate the flow to the tree emitters.
  • All control valves are currently setup to come on at the same time and remain on for the same duration.  In future tests there may be some variability in the "on time" for each row to setup different conditions of the test.
  • Future plans are to utilize the common feed header to a) fertilize the entire orchard section using organic fertilizers to determine the response between deep drip irrigation and surface drip irrigation and b) to utilize rain water captured in the irrigation scheme for each drip type.

Each tree, control trees and trees with the in test setups have been measured at a noted height and document for growth status at the beginning of last seasons growing season and will be measured once again at the beginning of this growing season.  This method of measurement will be statistically utilized to determine the impact of each irrigation system on the tree rows growth.

SARE Project Discussion 2020

Final Report 2022

Although this represents the final report for this project, it is expected that our team will write a phase 2 project to continue the efforts and determine conclusively which system results in the best use of water for a hazelnut orchard.

To make a systems comparison, the following different systems are discussed.

General Discussion of Each Orchard Irrigation System

The surface drip system used in this project is a very common means of irrigation for many growing applications where you provide irrigation water from a source, through a series of delivery tubes in the tree rows, to emitter tubes to the final emitters.  These emitters give a controlled level of water for irrigation to each tree and the entire system can be controlled from central control point(s).  There are many variations of this system but this represents a common one.

From website sources, the following is a chart showing the general cost per acre for this type of irrigation system compared to subsurface irrigation systems.



So in this analysis the above ground or surface systems range from $500 to $3,000 per acre and the subsurface systems range from $1,000 to $4,000 per acre.  For this kind of an increase in cost per acre, there must be benefits that are obtained for an agricultural organization to choose the subsurface system, which is a part of the intent of this study to determine.


DRI Product Information.

The following is a list of benefits from the DRI Deep Drip Emitters.

  1. SAVES WATER: By DIRECT DELIVERY of water to the root, unlike surface watering systems that lose enormous amounts of water to run-off and evaporation.




  1. EASY TO INSTALL: Each unit takes an average of 30 - 60 seconds to install.


  1. CONNECTS TO YOUR EXISTING EMTTER: So you don’t have to replace any parts! The DRI-12 is a simple addition to what you already have.


  1. PROMOTES DOWNWARD ROOT GROWTH: This improves the plants resistance to drought and disease. Drip systems can encourage J-root and shallow root development making the vine or tree more vulnerable.


  1. REDUCES MINERAL BUILD-UP ON EMITTERS: Warm air flowing around drip emitters causes water loss to evaporation. This process results in a calcification build up causing clogging. The DRI-12 seals, contains and directs water to the root zone without air interference.


  1. ALLOWS YOU TO DIRECT LIQUID FERTILIZERS TO THE ROOT ZONE: This minimizes the loss of fertilizers to run-off and displacement.


  1. REDUCES WEED GROWTH: Because the DRI unit goes directly into the ground it will not provide an easy source of food and water for pests as do drip systems.


  1. ENVIRONMENTAL BENEFITS OF THE DRI design: Besides saving water, the DRI unit considerably reduces the amount of fertilizers entering our rivers and streams as a result of run-off from surface watering systems. The DRI design also lessens the impact of toxins in our waterways because of its controlled underground delivery.


  1. ECONOMIC BENEFITS OF THE DRI design: A Napa Valley area vineyard recently lost 2,500 vines on their hillside vineyard due to drought and an inefficient surface watering system. That kind of crop loss is happening all over the globe. DRI increases revenues by preventing losses such as this.


Note; it can be said that the White PVC deep drip system shares most if not all of these above listed benefits.


DRI provides a video of the installation at Print (dri-products.com) and the following instructions for installation of the DRI-18 that we installed.

The DRI-18 unit is used for large heritage landscape trees. Start by poking a hole about 22 inches deep about 4 to 6 feet away from the base of your tree. Insert the DRI-18 unit so the top of the soaker, with the 1/4 inch tubing, is buried about 3 inches below the surface of the soil. Compact the dirt to fill the hole around the extending 1/4 inch tubing. Attach the 1/4 inch tubing to a drip emitter with a “woodpecker-type” nipple. The flow rate of the emitter should be appropriate for your tree size and soil type.

An expected advantage of the DRI-18, which is a foam emitter the length of the unit, is the even distribution of water along the length of the tube where the White PVC tube system would mostly distribute water at the last 3” of the emitter tube.

White PVC Subsurface Irrigation System

The white PVC subsurface Irrigation system is a DYI set of components using ¾” PVC tubing cut to length and with approximately a 3” notch or saw cut from the bottom up for water delivery range. From HomeDepot, a 10’ long piece of ¾” PVC pipe can be purchased for approximately $7.00 or a price of $0.70/lineal foot.  Therefore, the base tube for a 2’ long piece would be about $1.40/piece.  Added to that would be a ¾” PVC pipe cap (slip x slip) at $0.82 and the total materials, not counting the drip tube and emitter would be $2.22 each.

Labor required would be;

  1. Cut ¾” PVC to length, estimated at 60 seconds to cut 1 10’ long PVC tube (12 seconds per piece)
  2. Notch 3” at the end of PVC pipe estimated at 20 seconds each
  3. Drill hole in ¾” PVC pipe cap, estimated at 30 seconds each

So labor is estimated at about 1 minute each for the basic setup of a chop saw, a band saw and a drill press.  As labor costs vary, it’s difficult to quantify the cost but a a loaded rate of $20/hour (non-skilled labor) it would be less than $0.50 so the total labor and materials for this option, not considering the cost of tools, would be less than $3/tube.  Likely a minimum of 2 tubes are required per tree.


Other factors to consider are the impact of each drip irrigation system on the operations of the orchard like vegetation control, damage to the drip emitters through seasonal activities and the general impact on operations.  Here are our thoughts for these areas.

  • Above native vegetation in the Orchard;
    • Theres an increase in vegetation around the trees from the surface drip options that is less obvious in the other two methods.
    • The DRI subsurface system has distribution of the irrigation water at or just below the surface so although it has less vegetation growth tendencies than the surface drip system, it still provides some water to the native vegetation to support growth around the to of the delivery tube.
    • The PVC tube subsurface system provides most of the delivery of wat to the lowest 2” to 3” of the tube so less water is provided to native vegetation except at an extreme level.
  • As it is our practice to not completely eliminate the vegetation around the trees as is common in most hazelnut orchards through the use of herbicides, our practice is to do a much-reduced application of herbicides throughout the growing season.
    • Therefore, our practices include more mowing and “weed whacking” to which the two deep drip systems often get in the way of causing damage to the pipes and emitters.
    • Subsurface irrigation systems have seen damage to their delivery tubes coming from the tree line header at a higher percentage than the normal surface drip system as they are spread out further from the trunk of the tree resulting in more frequent contact from week whacking.
    • This is an area that we need to work on to obtain the low level of vegetation around the trees, keep our minimum practice of reduced herbicide application but equally minimize the work and the damage to the tubes and emitters. We will be working on these practices in this next phase.
  • In the rest of our orchard, our practice is to roll out our tree line header lines prior to the irrigation season and roll them back up in the fall after irrigation is completed. This practice a) allows us to reuse and maintain the header lines year on year without off season damage, and b) allows us to mow between the trees in off season until we need to roll out the lines for the next season.
    • The surface drip systems support this method of installation and removal seasonally and we are well suited for this process.
    • The DRI foam subsurface drip system would require more disassembly of the lines from the tree line headers before they can be rolled up causing potentially damage to the insertion points in the plastic tubes requiring more annual replacement needs. Also the DRI-18 units inserted into the ground, unless removed annually, would still be in the way of the process of mowing or weed whacking between the trees.
    • The white PVC tubes inserted into the ground have the same impact regarding the need to mow or weed whack around the trees however the removal of the lines can be done easier as they have simple caps that can be pulled from the PVC tubes thus allowing us to roll them up like we do with our other surface drip system.

We also have not worked with these systems long enough to know the life of them and/or the ongoing maintenance needs of each.  These we will consider and work on as we continue to use them in our operations.

Effects of Subsurface Micro-irrigation on Water Use Efficiency

Research results and discussion:

To date there is insufficient information to make any determination of the impact of any of these irrigation method compared to the other.  The first point where this will be possible will be later into the growing season.  Measurements will be taken this spring as well as later in the season for data collection and will be reported in next years report.

2022 Final Report

As planned, throughout the growing process, tree survey’s were taken to compare the growth characteristics of each tree year on year and to compare methods from one irrigation type to another.  These measurements included a micrometer measurement of the tree trunk at a specific height each year, the height of the tree, the diameter of the canopy, the condition of the tree, the general amount of nuts produced and other notes about the tree that the survey team determined were noteworthy.

The following table is an example of the survey report that was used for each row in each year.

Field 1                        
Row E                        
          Condition      # Nuts        
Tree Mic Ht Mic Read Height Diameter Good Med Mod Poor Good Med Mod Poor Notes
1     32         x       x barely alive
2 8 0.61 60 32     x       x    
3 24 1.17 96 53 x         x      
4 24 1.01 101 37 x       x        
5 24 1.01 95 37 x         x      
6 24 0.9 82 47   x       x      
7 24 0.93 72 36     x       x    
8 24 1 97 47 x         x      
9 22 0.82 74 45 x         x      
11 24 0.7 60 31     x       x    
12 22 0.9 76 39   x         x    
13 24 0.92 74 46   x         x    
14 24 0.82 84 52 x       x        
15 24 1.7 105 68 x       x       great tree
16 24 0.95 81 39   x       x      
17 16 0.14 39 17     x         x  
18 24 0.84 85 32     x       x    
19 18 1.3 92 48 x       x        
20 24 1.3 106 62 x       x        
21 24 1.21 94 57   x       x      
22 24 1 85 45   x       x      

Table; Example of Row Survey Report with year-on-year growth changes.

Note: the same survey personnel were used in each year survey to maintain the most accurate measure of tree growth status.

These individual row measurements were then used to compare the various types of drip systems and see if there was in fact a pattern of performance that could be observed from the data sets.  The following table was obtained and is presented as the best analysis of the data available for each data set when comparing the different drip types to one and other.

Summary Page        
Row Drip Type Thk % Chg Ht % Chg Dia % Chg  
B Surface Drip Control Row 48.0% 35.6% 28.3%  
C White PVC Deep Drip Row 29.6% 18.8% 22.8%  
D DeepDrip Black Foam Row 23.0% 15.2% 27.8%  
E Surface Drip Control Row 33.1% 15.5% 23.8%  
F White PVC Deep Drip Row 27.4% 15.7% 20.1%  
G DeepDrip Black Foam Row 21.6% 19.7% 27.5%  

Table: Comparison of each row/drip type based on the years 2020 and 2021

Rows B and E were the normal surface drip systems and from most indications seemed to outperform the other types of drip systems, the PVC deep drip and the DRI deep drip system.  In looking at the data more closely, Row B has the greatest amount of growth in all categories which leads to a question of what is different regarding this row.  Observations show that all vegetation in the lower part of this row, especially the grasses, have a faster rate of growth than almost all other rows leading to a conclusion that this row may have a greater amount of natural water available since, it is the lowest point of this field and therefore likely would show this greater growth characteristic anyway.  This leads to a greater reliance on the other control row, Row E.

Row E, the other control row has the second greatest amount of thickness change within the rows behind row B, the 5th greatest amount of height change and the 4th greatest amount of canopy diameter change of all rows measured.  Resorting the data for each category yields Table 3 data.


Thickness Change



Height Change



Canopy Dia. Change




% Chg.






% Chg.
























































Table: Resorted results for each category measured, years 2020 and 2021.

So, if we ignore the Row B and assume that it has a distinct advantage due to normal water flow of the field, then we have a very different picture of the performance of each drip irrigation type.  Therefore, we could arrive at the following conclusions.

  • The control or surface drip remains the dominate performer in the area of trunk thickness change year on year with the White PVC system closely following and the DRI a distant 3rd in performance.
  • In height change year on year, the Row G DRI comes in first (ignoring Row B) and the Row D DRI system comes in last in this grouping. The White PVC pipe system of Row C comes in at less than 1% difference of Row G with the White PVC pipe system of Row F 4% less that Row D and just slightly better than the Control Row E and DRI Row D.
  • In the measurement of canopy growth, the DRI system rows were both significantly better than the control (4.8% and 4.5% respectively greater than the control) and the White PVC system was about the same as the control and almost 3% less than the control respectively.

These conclusions are interesting but do not define a clear best option for field selection of which irrigation system to choose.  The surface drip wins on the increase in tree thickness, the DRI and White PVC systems seem to be about equal in tree height increase and the DRI clearly leads in the area of Canopy diameter percent change. 

Other factors to consider are the impact of each drip irrigation system on the operations of the orchard like vegetation control, damage to the drip emitters through seasonal activities and the general impact on operations.  Here are our thoughts for these areas.

  • Theres an increase in vegetation around the trees from the surface drip options that is less obvious in the other two methods.
  • As we do not completely eliminate the vegetation around the trees as is common in most through the use of herbicides, our practice is to do a much-reduced application of herbicides throughout the growing season. Therefore, our practices include more mowing and “weed whacking” to which the two deep drip systems often get in the way of causing damage to the pipes and emitters.  This is an area that we need to work on to obtain the low level of vegetation around the trees, keep our minimum practice of reduced herbicide application but equally minimize the work and the damage to the tubes and emitters.  We will be working on these practices in this year.
  • We also have not worked with these systems long enough to know the life of them and/or the ongoing maintenance needs of each. These we will consider and work on as we continue to use them in our operations.

The original project was intended to include 3 years of actual data collection. Due to the time the funds arrived and the lateness in the season which created difficulties in drilling for the deep drip components, we were only able to collect data in years 2 and 3.  The hopes would be that a 3 year of data collection would in fact support more precise conclusions regarding the best performer in this study.  Therefore, the plan is to continue to collect data and see if after this third year of collection, we can do a better job of determining the best option for application to hazelnut growing.

Participation Summary
1 Producers participating in research

Research Outcomes

1 Grant received that built upon this project

Education and Outreach

2 Consultations
1 Curricula, factsheets or educational tools
1 Webinars / talks / presentations

Participation Summary:

1 Ag professionals participated
Education and outreach methods and analyses:

We will organize two field days at the research site. One field day will be post-harvest, taking place sometime in October of Year 2, another field day will be post-harvest, taking place sometime in October of Year 3. This will allow participants to look at the growth and also see how the management activities of the orchard irrigation has impacted tree development relative to each irrigation type. We will connect with both Washington State University and Oregon State University annual scheduled farm tours for inclusion in their stops. We will also work with the Hazelnut and Organic Hazelnut Associations to include their members in a tour of the research farm site as well as regional County extension and Soil Conservation Groups.

Note on Field Days: Due to Covid-19 restrictions, it was not feasible or acceptable to have onsite field days.  It is hoped that as vaccinations occur and the pandemic situation is brought under control, that we will be able to have field days in this next year.  This also allows us to gather more data and be able to support early conclusions about the measured improvements in the various trees with deep drip irrigation systems compared to conventional surface drip systems.


In addition, the project team will write and distribute two publications. One will be a lengthy and detailed final SARE report that will be available to anybody who asks to see it. The other will be a shorter, 2-3 page “how-to” guide written in non-academic language about which irrigation system options best meet certain growing conditions including benefits realized, costs of installation, equipment needed, etc. This shorter publication will be handed out at the field days and paper or electronic copies sent out to our regional Extension offices, conservation districts, and NRCS partners.

The first of these publications, the 2 to 3 page "how-to" guides will be written in the next 8 to 10 months after measurements are taken to determine early effects of the deep drip systems in comparison to the surface drip control systems.  These will be distributed as referenced above but with the possible exception of handouts provided at field days, which will be determined as the pandemic is brought under control and the State of Oregon releases restrictions on face to face meetings/events.


We will also actively cultivate trade media attention for this project by submitting articles and inviting journalists to write about it.  Publications we will approach include the Good Fruit Growers magazine, the Capital Press newspaper, OSU Extension Orchardist e-newsletter, as well as spreading the word via select social media outlets. This will be especially helpful in getting the word out beyond our region to other fruit and nut growing regions of the country.

Trade media and other publications will also be explored in this current year as due to the late start on the project, results are not yet available but should be available by this fall following detailed measurements of each tree in the test. 

Table 1: Educational Outreach Timetable

Educational Deliverable-Timeline

Post-Harvest Field Day-October 2020  Changed to October 2021

Post-Harvest Field Day-October 2021  Changed to October 2022

Orchards Irrigation Options “How-to” Guide-Completed by October 2021  Changed to October 2022

SARE Final Report-Completed by December 2021

Articles in trade publications-2020 and 2021  Changed to 2021 and 2022

Social Media Outreach-2020 and 2021  To begin mid-2021

Educational Materials to be Produced:

  1. Organize and deliver two field days at ZD Farms, estimating attendance of at least 100 farmers and agricultural technicians/educators in total. One field day will likely occur in Year 2 and one in year 3.  Delayed due to Covid-19.  Will schedule once restrictions are lifted
  2. Publish a 2-3 page cover crops in orchards “How-To” guide written in non-academic language to be distributed freely through farmer networks, at field days, through government agencies, and online. This will be written at the end of the three-year project in order to capture all of the data collected and interpret the results.  Still planned for the end of the project in 2022.
  3. Write annual progress reports and a more comprehensive final report for SARE, also to be made available to anybody who requests it, at the end of Year 3.  Ongoing.  Adjustments being made due to late start (funding timing) and Covid-19 restrictions.
  4. Submit articles of approximately 1,000-1,500 words to the Good Fruit Grower magazine, Capital Press newspaper, and our local OSU Extension regional e-newsletter. Alternatively, ask their editors to write about our irrigation system research using information that we furnish to them. The media will also be invited to our field days. Years 2 and 3.  Ongoing
  5. Engage in social media outreach to disseminate the research information via Facebook pages of the farmer and partners, partner e-newsletters, orchardist online forums, and others. Years 2 and 3.  To begin in 2021.

Final Report Notes: Covid has continued to be an issue and therefore we have not considered any field days and will attempt to utilize other methods of minimal contact to get the message out on the field trials and results.

As covid issues continued, we were unable to find ways to do personal contacting and presentations of the project path and the results but still have intentions to do more in this area.

  • We have done postings on social media throughout the project timeline and will continue to do this.
  • We are looking for opportunities to do an interview with a popular press periodical that serves the grower industry like Western Farm Journal or West Coast Nut periodical. As we feel that we have an incomplete project, we have not done anything in this area but hope to fulfil this in the next year or two as we process more information about the growing traits for each deep drip irrigation system.
  • We will be presenting the results to the Organic Hazelnut Organization for their website.
  • Complete and distribute the How To Guide for those that have an interest.

While we feel that there’s a good amount of information to discuss, we do believe that additional years will be essential to get a full understanding of the true value of each irrigation type for our orchard so we may be able to better guide those that have interest.  Therefore, we will be filing for a Phase 2 project to improve our project efforts and obtain the needed years of performance for a better conclusion.

1 Farmers intend/plan to change their practice(s)

Education and Outreach Outcomes

Recommendations for education and outreach:

Initial installation challenges have identified that best practices to reduce labor, drill bit loss and damage to drill motors would be to do the installation work earlier in the season, likely early to mid-spring time.  This adjustment allows for work in soil that is softer and easier to work.

More information is needed on hazelnut root development for the varieties growing in Oregon that can be related to any changing root development defined from this study project.

Near the conclusion of the project, the team will look for similar sized trees from each irrigation group to remove and evaluate the root stock variations.

Final Report

Throughout this process we have been learning many things about the process of installation, the processes of maintenance and as we go forward the longevity and performance benefits of each irrigation type.  We firmly believe that continuing the study will only clarify these things and help us lead to a true set of best practices that we can communicate to those that have an interest in reduction of water usage, enhancing nut tree growth and overall benefits to their growing operations.

1 Producers reported gaining knowledge, attitude, skills and/or awareness as a result of the project
Key changes:
  • The project funds were received late in the growing season of 2019 which did not allow for installation completion until after the growing season was completed so no progress was made towards collection of data for each irrigation method. During this time, the following things occurred.

    - installation of the 3 types of irrigation. 1) standard drip irrigation, 2) Deep drip PVC pipe irrigation, 2) DRI foam deep drip emitters
    - final determination of the control valves and flow monitoring components for each test row. These will be installed Spring of 2020.
    - measurement of each tree in the test. Measurements include height, condition and micrometer reading of each tree at a certain height for establishing a benchmark for each tree in the test.

  • Another key area of this project that needs to be addressed is the knowledge obtained within the installation process including tool requirements and time needed for installations. Due to the late start on the project into the hotter season, and as a result of the harder soil conditions in the orchard, the drilling of holes was more challenging than would have been in the earlier part of the season. This harder soil condition effected not only the time to drill each hole (2 holes per tree that required deep drip components) but it also impacted the longevity of the drill and drill bits used in preparing the holes for the emitters. Statistics were taken for the number of holes drilled and the time required to drill them throughout the process. Since some areas were even harder than others, in some cases the drilling could not be done in the ideal area and had to be moved around the permiter of the tree until a suitable area that would allow for the intended depth could be found, thus causing additional holes to be drilled for some locations. In the process 2 drill bits were broken at either the connecting point of the drill (the chuck) or at a point further down the drill shaft. Additionally 2 drills were damaged or overheated in the process of drilling and required purchase of other drills to complete the process.

    For comparison, some of the pipes that were installed in locations that are less than desirable, will be re-drilled this spring when the soil warms and times will be kept for comparison to the times needed to drill in the previous year. The time comparisons will be reported in future reports.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.