Tile drainage in Massachusetts cranberry production: Implementation and best management practices

Tile drainage in Massachusetts cranberry production: Implementation and best management practices

Summary

Tile drain function was studied extensively on two of the project advisors’ farms in 2015. Tile function in conveying water and nutrients was the focus for the project graduate student; he completed his field research this year and is currently preparing his thesis and accompanying papers. One interesting outcome of his project was the finding that about 1/3 of all seasonal water conveyed through the tiles came from summer rain events, making those events of equal potential for amount of water leaving the field as is discharged in the harvest flood. This has implications for potential soil saturation in the absence of tiles during a part of the growing season when well-drained soil is essential to crop production and quality. The importance of good seasonal drainage was supported by research results at our other participant site where we studied two depths of tile installation. The grower at that site also encouraged us to compare that bed to a more well drained adjacent site with tile installed. That comparison pointed out the limitation of tiles in mitigating soil saturation: not all sites benefit to an equal extent by tile installation. Subsoil type also plays a role. The first farm was the site of an on-bog workshop in May 2015 (16 participating growers), the other farm will host a workshop in April 2016. The results of a grower survey in January 2015 (n=90) indicated that growers remain committed to tile installation (38% planned installations in 2015) on renovations and new plantings (59%) and for retrofitting existing beds to improve drainage (61%). We plan to host a field day in March or April 2016 to demonstrate technique for retrofitting tiles.

Objectives/Performance Targets

Fifteen growers install tile drains on a total of 140 acres (1% of MA acreage) with five incorporating project-developed BMPs for installation, maintenance, and irrigation supplementation, resulting in increased yield of 20 barrels/acre (~$850/acre), reduction of sprinkler irrigation cycles (quantified energy and water savings), and the elimination of at least one pesticide application per year.

Accomplishments/Milestones

Milestones:
1. Five growers sign on as early adopter participants/project advisors; one provides the site with varied horizontal spacing (experiment 1). Completed 2013.

2. 300 growers learn about project including data collection requirements of those that participate and receive a survey regarding current drainage practices and challenges. Completed January 2013.

3. 200 return survey, 150 are interested in additional education, 30 are interested in establishing drainage for project evaluation. Surveys were conducted in January 2012 (n=171), 2013 (n=118), 2014 (n=115) and 2015 (n=90). Results through 2014 are included in the 2014 progress report, the 2015 results are attached to this report.

4. Five growers install tile drains with guidance from the project team and advisors and keep records.  The largest grower on the project team is planning a twenty-year project of adding 100 new acres – these will include tile drains. The planning for this installation has included consultation with the project scientists. In the January 2015 survey, 31 respondents reported installing tile in 2013, 22 installed tile in 2014.

5. Growers and team members produce a first draft of the BMP and have selected the site and spacings for Experiment 2. Horizontal spacing experiment (1) was completed by 2013 and additional evaluation of a 20 foot spacing continued through the 2015 growing season. The vertical spacing (depth) experiment (2) was established in 2014. BMP development is ongoing.

6. Early adopters evaluate practices on their farms and host on-farm workshops. The team conducts and evaluates experiment 2. Data from the evaluation of the vertical spacing site (exp. 2) are attached to this report. An on-farm workshop was held at the 20 foot spacing site (graduate student project) in May 2015.      

7. Growers attend on-farm workshops, sign up for personal design and installation assistance and follow-up. Interim information is disseminated at winter meetings and brief surveys are conducted at the meetings to verify progress towards performance target. The tile function evaluation study of graduate student Nick Alverson was presented in poster format to the 2014 grower meeting (attendance 262) along with a PowerPoint presentation by Casey Kennedy of that study and the tile depth work [see 2014 report]. The site for that study was the location for an on-farm workshop in May 2015. Dr. Kennedy also presented project results [see 2014 report] at the winter meeting of the Cape Cod Cranberry Growers Association in March 2014 (attendance approx. 250). A survey was conducted at the 2014 January meeting and at the January 2015 meeting.          

8. New adopters have installed drainage and are evaluating the practice by Year 3. In the January 2015 survey, 31 respondents reported installing tile in 2013, 22 installed tile in 2014. A subset of those growers will be interviewed in early 2016 about their experiences.

Remaining to be done:

• On-farm tour of the tile depth experiment site (spring 2016).
• Final on-farm demonstration of tile retrofitting, including video to be posted to the Cranberry Station website (spring 2016).
• BMP factsheet is distributed at the retrofitting demonstration, as an insert in the May Cranberry Station newsletter (circulation ca. 280), and on the Station’s website.
• A final phone and in-person survey of adopters (June 2016).

Discussion:

Grower surveys in 2012, 2013, and 2014 show that, consistently, larger acreage growers were more likely to have tile drains on at least some of their acres and are most likely to install additional drains. The barrier for smaller growers appears to be primarily financial, with the majority of growers viewing tile drainage as an advantageous practice. The 2015 survey (summary attached), confirmed that larger growers are most likely to have tile installed and that growers with tile on their farms are more likely to install more compared to those that have no tile. It is about equally likely that those installing tiles are retrofitting existing beds (61%) vs. installing tile in renovations or new plantings (42% and 17% respectively).

Survey responses confirmed the information provided by the team of 5 early adopters: most Massachusetts growers are installing drains at a depth of 6-12 inches (to the top of the pipe), owing to a relatively shallow peat layer and a paucity of accessible sand (at least by comparison to farms in Wisconsin and the Quebec Province of Canada), and the 20-foot horizontal spacing is the most common. The 20-foot spacing was also associated with the the greatest yield in our first experiment and was the spacing at the graduate student project site. That horizontal spacing accommodates working around existing sprinkler pipe spacings, especially important in retrofits. We are focusing on retrofit applications for several reasons – they can be used to drain isolated wet areas of beds (identified as a primary motivation for growers to use tile drains) and they can be done as spot or partial installations, saving money. We plan to demonstrate a retrofit installation in the spring of 2016 with a grower field day and production of a video for posting to our website.

In the spring of 2014 (delayed by one year due to grower financial constraints), a tile depth experiment was established on the farm of one of the project participants. The bed in question was renovated and replanted. Tiles were space 20 feet apart at either 8 inches to tile bottom (4-6″ to top) or 12 inches to bottom (8-10 inches to top). The depths chosen encompassed the most common depths listed in our surveys (between 6 and 12 inches). Site hydrology, crop yield, and crop quality (fruit rot incidence) were evaluated in 2015 (report attached). The subsoil of this bed is a thick peat layer which is the likely cause of very wet conditions throughout the summer of 2015. At the suggestion of the grower, we compared that bed to a nearby new planting on an upland soil base; the upland bed was substantially less saturated despite being irrigated similarly to the depth study bed (see attached file). While tile depth in the peat-based bed did not affect soil moisture content, crop yield was greater and fruit rot incidence was lower in the areas with the deeper tiles. In the upland bed, where tiles were at the deeper depth (12 inches to the bottom), crop was significantly greater and fruit rot incidence was substantially lower compared to the wetter bed. This points out the importance of including monitoring of soil moisture and irrigation management as part of the BMP guidance for tile drainage use and for continued study of disease incidence with and without tile drains.

These results suggest that subsurface tile drainage may enhance rapid drainage in cranberry beds, but does not represent a universal solution to poor drainage in wetland, peat-underlain, cranberry beds. This reinforces an anecdote we reported in 2014 – that installation of drains needs to be above the peat subgrade in order to maximize soil drainage and improve crop. In the experiment site, the tiles were above the subgrade, but apparently the influence of the subgrade continues to be important.

Tile function in conveying water and nutrients was the focus for the project graduate student; he completed his field research this year and is currently preparing his thesis and accompanying papers. An on-farm workshop was hosted at this site in May 2015. One interesting outcome of his project was the finding that about 1/3 of all seasonal water conveyed through the tiles came from summer rain events, making those events of equal potential for amount of water leaving the field as is discharged in the harvest flood. This has implications for potential soil saturation in the absence of tiles during a part of the growing season when well-drained soil is essential to crop production and quality. The increasing frequency of large rain events that may be related to climate change, points out the need to continue to improve our ability to rapidly drain cranberry beds.

• LNE12-316SurveySummary2015
• LNE12-316Tile_depth_study

Impacts and Contributions/Outcomes

The topic of tile drainage continues to be of great interest to MA cranberry growers. The very active frost season in the 2013 spring and the record rainfalls in June 2013 and July 2014 point to the need to be able to drain away excess moisture in the cranberry beds. Experimental components on partner farms are completed and confirm that 20 feet is the most advantageous horizontal spacing for tile drains in cranberry beds. Also confirmed is the potential role for tile drains to mitigate against large rain events during the growing season and, along with soil moisture monitoring and irrigation management, assure good yields of high quality fruit. Proper water management has huge potential and implications in cranberry fruit rot disease management, the pest problem responsible for the most pesticide applications in Massachusetts cranberry.

While project participation began slowly primarily due to financial constraints, we have seen steady implementation and 38% of growers surveyed (n=90) in early 2015 planned to do installations during the year. The on-farm workshop in spring 2015 and those to be held in spring of 2016, including a retrofit installation demo, should help to continue interest and education on how best to implement this technology. The core group of project farmer-advisors remain well engaged and committed to the use of tile drains and to sharing information with fellow growers. One is planning a 100-acre expansion project, including the use of tiles. We have engaged with additional growers who are sharing experiences and who will also be important in helping to finalize the BMP recommendations for tile use. While our progress has been delayed due to current industry economic conditions, we remain confident that we will reach our target goals.

Collaborators: