Hops and Irrigation...
In 2011, we conducted a Northeast SARE grant experiment to investigate the benefit of adding drip irrigation to crop yield, as well as to test the weed suppression effect (and subsequent crop yield) of straw versus summer alfalfa used between the hops crowns (FNE11-711). Though the summer of 2011 was a very rainy one here in northern Maine (with 9" more rainfall than average!), the benefit of irrigation on hop yield was still clear. Our mature three-year old Nugget plants that were irrigated produced three times as much weight in hops as their neighboring row that wasn't irrigated!
We also tested two weed suppression methods - using straw or summer alfalfa to smother weed growth. We found that using summer alfalfa did not greatly improve either hops yield or soil nitrates, and given that it was more labor intensive to do, we recommended that was not a good approach for the future. Weeds are a big problem in small scale organic hops cultivation, and we observed that straw did a better job of smothering weeds than summer alfalfa.
To read the full version of this 2012 SARE report, entitled “An experiment on the effectiveness of cover cropping and irrigation to produce sustainable hops in Maine”, click here to download a pdf version.
Our natural curiosity about improving hop yield, quality, and best practices in growing hops organically, coupled with both our backgrounds in science, has led us to investigate some of our hop growing questions using an experimental approach. We figured there must be lots of other hops farmers, especially in the Northeast, who were asking the same questions as us and would like to know about some of the things we were investigating.
Over the years, we have been fortunate to work with a USDA program called Sustainable Agriculture Research and Education (SARE), which provides grants and education to advance innovations in sustainable agriculture. We have also partnered with the University of Maine, and received a Maine Technology (MTI) Seed Grant to fabricate a prototype hop harvester. More detailed information on each project can be found below.
Organic Hops and Weeds...
We spent 2012 and 2013 conducting a SARE experiment to investigate best non-herbicide approach to weed management in developing a new hopyard (FNE12-742). As we expanded a new 3-acre hopyard beginning in 2012, we experimented with weed-suppressing rapeseed as a cover crop, as well as three different weed maintenance approaches (straw mulch, tilling, or a control with nothing done).
The complexities of weed management in an organic hopyard are evident in our experiment, but here are some of the “take home” highlights… We found that rapeseed did not have a measurable positive effect on plant growth or weed suppression, and so there was little evidence that waiting a year to plant hops was beneficial. Straw cover showed better measures of weed suppression in first year plants, but hops wet mass in two-year old plants (mainly based on Cascade) was actually higher in the tilled plots. We concluded that the best practice will likely involve a mixed approach that involves more intensive springtime tilling and weed management, followed by summer straw mulching, with a particular focus on preventing persistence and establishment of perennial weeds like goldenrod that can be propagated by rhizomes and seed.
If you are interested in reading the full version of this 2014 SARE report, entitled “Evaluating cover cropping and non-herbicide weed management strategies in hops, a perennial crop”, click here to download the file.
A paper based on this experiment, entitled "Strategies for Weed Management in Organic Hops, A Perennial Crop", has also been published in Agronomy Journal in February 2015.
Fertigation in Organic Hops
Our Northeast SARE grant for the 2014 growing season (FNE14-796) investigated the best timing and amount of organic fertigation in hops. Fertigating resulted in a significant increase in wet hop yield, with one fertigated group resulting in a 57% increase in wet hop mass over granular delivery, and the other fertigated group resulting in a 75% increase. Soluble, high nitrogen, and organic fertilizers for this type of application are still quite expensive, however. Click here to download the full final report.
Prototype Hop Harvester
In 2014, we receive a Maine Technology Institute (MTI) Seed Grant to fabricate a prototype hop harvester based on an open-source design originally produced by the University of Vermont (UVM). This small-scale mobile machine fits the needs of Maine commercial hop growers, as previously there was not the right capacity machinery available in this part of the US (a Goldilocks-like problem... "this one is too small, this one is too big"). The mobile design also has the potential to be shared or contracted, a bonus for farmers who want to create a cooperative model of hop growing. We partnered with the very capable team at Maineline Welding & Fabrication in Blaine, ME to produce our prototype, which harvested our 2014 crop nicely. If you are interested in having Maineline Welding & Fabrication fabricate a hop harvester for you, please contact them at (207) 425-4621.
Hops Baler Project at University of Maine, Orono
We are grateful for our hops baler that helped upgrade us from the two plastic bucket "sandwich" system of the past! It is the result of a senior engineering project at The University of Maine, including a team comprised of Jacob Speed, Matt Gallagher, Nathan Rocker, Sam Ledue, and Lloyd Bryant. Their hard work allowed us to package nice square bricks for fall 2013 - they stacked nicely in the freezer and shipped easily, not to mention cut down on time compressing the hops before sealing.