Soil Nutrition and Fertility Options for Organic Hop Growers in the Northeast

Final Report for FNE11-704

Project Type: Farmer
Funds awarded in 2011: $4,417.00
Projected End Date: 12/31/2012
Region: Northeast
State: Vermont
Project Leader:
Fletcher Bach
Square Nail Hops Farm
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Project Information


The purpose of this research project was to determine, by the end of one growing season, which of the selected applications produced the most biomass, exhibited the least pest damage, and utilized the most available nutrients in the soil. This project compared five different application types and had three replications of each. It used a combination of collection methods, both qualitative and quantitative to determine which application was the most effective. We used each application as directed on by the instructions on packaging or from company representatives. We applied Chilean Nitrate at a rate of 6oz per plant, once during the season. We applied Biplantol by spraying the prepared soil in fall prior to planting, and then applying by backpack sprayer three times throughout the season at a rate of 27 FL OZ per acre.

Unfortunately, it found that none of the application types served as a clear best practice. Results might have been unclear in part because this research was conducted on first year hop plantings as opposed to an established hopyard. Also, because of the types of nutrient applications used, his kind of study might have granted more meaningful results if it had been conducted on an established hopyard and continued over multiple seasons.


Square Nail Hops Farm located on the Birkett Farm in Ferrisburgh, Vermont has been an active farm since 1803. Since that time, the farm has focused on an assortment of farming activities ranging from maple sugar, orchards, and horses, to more recently, hay, cows, and goats for dairy. The newest focus for the Birkett farm is Square Nail Hops, a business started by Fletcher Bach and Ian Birkett in 2010 that grows hops for breweries in the area.

Growing with two acres in hop production, the farm grows more than 10 varieties in total with five varieties planted in quantity scaled enough for commercial breweries. The five varieties were chosen after extensive variety trials to choose the hops that were both most marketable and most vigorous. We have Cascade, Centennial, Willamette, Chinook, and Nugget in commercial production. For the NESARE farmer project, we used the Cascade variety only.

The Square Nail Hops venture is bringing new life to an ailing former dairy and serving as a much needed on the ground example for other farmers throughout the Northeast who wish to add hops to their farming operations.

All of the research for the NESARE Farmer Grant project was conducted by Joseph Birkett, Ian Birkett, and Fletcher Bach. Joseph Birkett is the land owner and contributed an equal third of the on farm labor hours for the FNE11-704 research project. Ian Birkett and Fletcher Bach contributed equal thirds each of on farm labor hours. Fletcher Bach drafted the grant report. All technical support came from Rosalie Madden.

Project Objectives:

The goal of this project was to determine, by the end of one growing season, which of the selected applications produced the most biomass, exhibited the least pest damage, and utilized the most available nutrients in the soil. In conducting this research, we wanted to learn the best way to efficiently produce the healthiest plants possible in an establishing hopyard, while at the same time minimize pesticide use. This project includes applications that were all certified as organic at the time of the project start.


Click linked name(s) to expand/collapse or show everyone's info
  • Ian Birkett
  • Joseph Birkett
  • Rosalie Madden


Materials and methods:

We conducted our research on the Cascade hop variety rather than usimg samples from multiple varieties. Cascade is a variety that has shown itself to grow successfully in the Northeastern climate and is desirable to many home brewers and commercial brewers in the area. We kept our research restricted to the Cascade variety to provide continuity and focus in our results. Further studies could widen the scope of ours by including multiple varieties as each variety may require differing levels of nutrients and minerals.

In fall, 2010, we tilled Biplantol into the Eastern half of our hop yard (bottom half of Fig.1) to prepare the soil for spring planting. We designed the field to have three replications of each sample type to increase the likelihood of truer results. Our regular plant spacing is 3.5' between each hop hill. For the research project, however, we decided to allow at least 10' between each sample plot to prevent confusing or inaccurate results.

We used backpack sprayers to apply Biplantol, once in early June, once, in mid-June, and once in mid-July after flowering. We also soaked rhizomes for the appropriate sample plots in Biplantol for a half hour at the time of planting. All rhizomes not receiving a Biplantol soak were given a water soak for consistency. We used our AGCO 6065 tractor to dispense compost which we applied by shovel full to all plants in the fall and in the spring. We applied Chilean Nitrate to the appropriate sample plots at a rate of 6 ounces per plant. We had five different sample types with three replications each. These were BR, BC, B, CN, and X. (BR) where the soil was sprayed with Biplantol the season prior, sprayed with Biplantol throughout the season, and with rhizomes soaked in Biplantol solution at planting. (BC) where the soil was sprayed with Biplantol the season prior, and sprayed with Biplantol throughout the season, rhizomes soaked in plain water, and Chilean Nitrate applied. (B) where the soil was sprayed with Biplantol, sprayed with Biplantol throughout the season, but rhizomes soaked in plain water. (CN) where rhizomes were soaked in plain water, and Chilean Nitrate was applied. (X) control, where nothing was applied aside from the compost that all plants received.

We compiled data about all 15 of the sample plots by taking observations during regular scouting, photographs, by testing soil samples, and by taking a final biomass measurement of each bine.

Research results and discussion:

By conducting this research, we learned a great deal about our farm and our soil. One finding of significance for us was that the soil pH in our hopyard ranges from 6.9 at the southernmost sample plot to 7.3 on the north side. With Dr. Heather Darby's recent article about fertility guidelines for hops stating that a pH of 6.5 is optimal for hop plants, we might expect to see greater productivity and overall health exhibited by those plants closer to the southern side of the hopyard.

Even with a multitude of data collection methods, we weren't able to see an application that was head and shoulders above the rest in terms of productivity and soil health. There was enough variation between the three replications of each sample type that it's hard to tell if there was an overall best practice or if any inferences can be made. On an individual sample plot level, the worst performing hops were BC2 and BC3. They were small, yellowed, burnt, and exhibited necrosis from pest damage. These two plants may have performed so badly because of the direct application of Chilean Nitrate. Although we applied the CN at a rate approved by the packaging and our crop and soils technician, it seems it burned and weakened these two plants. Interestingly, the plant that produced the most biomass by the end of one season was BC1. This variation between each replication may have had to do with a cultural factor such as whether some CN landed directly on the foliage of BC2 and BC3. Looking at the graphs of our soil tests, one can see that the BC plots that were sampled contained the least amount of almost every nutrient or mineral. This may in fact be showing that the BC1 plant utilized more nutrients and minerals in its growth and that's why it produced the most biomass.

By averaging and graphing all of our collected data, we hoped to give less weight to the outliers and allow the broader trends shine through. In the end, however, it was data on the individual level that let us see any meaningful variation.

Our goal with this study was to determine which nutrient application was the most cost effective. For us, that included long term savings such as preventing spending on organic pesticides and herbicides. None of the application types performed better overall than the others. We will likely use a combination of the applications types to further determine which is the most cost effective for our situation. With horse farms close by, it may be that focusing on good compost will be the most cost effective way to build healthy soil.

The 2011 growing season was one of the hardest for many Vermont farmers. With Vermont experiencing two “once in a lifetime” floods in one season the water table was abnormally high. Our farm, however, avoided the damage from the high winds and water of hurricane Irene that many other farmers around the state did. One noticeable affect of the abnormally wet season, though, was that hops were ready to harvest two weeks earlier than 2010. This was also true for other hop growers in the area as well as grape growers from Addison and Chittenden counties. Overall, though the season's conditions likely had no significant effect on our research.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

We have learned so much about crops and farming practices because of the work that NESARE and the UVM Extension do. Because of this, outreach was and is a fundamentally important element of our research project. On July 8th, 2011 we hosted a field day that was publicized through the UVM extension as well as the Northeast Hops Alliance. At the field day, we shared our goals for the NESARE research we were conducting to around 40 participants with a presentation and handouts. Technicians and researchers from the Extension also gave presentations on various research projects related to nutrition and pest management. As the project concludes, we are sharing the results with the Northeast Hops Alliance as well as the UVM Extension who maintain blogs and email lists with wide reach.

Project Outcomes

Assessment of Project Approach and Areas of Further Study:

Future Recommendations

As there was no clear “best” performing application in our study, we will continue to compare different application types as the plants mature to see if there are any clear standouts. Our plant with the best performance was BC1, but after the start of the study, Chilean Nitrate was removed from the list of approved organic fertilizers. As we are an organic farm, we will seeks other sources of nutrition that are organic approved. As for Biplantol, it may have potential in increasing long term soil health and fertility. We will keep in touch with other growers in the area who use Biplantol regularly
and learn about its potential for long term soil improvement.

One factor that may have prevented clearer results was that we conducted this research on first year plants. It seems there may be more variables in an establishing hop yard, such as rhizome size at planting, that affect the final results. Conducting the same research project on an established yard might garner very different results. We also believe that this kind of study might be more effective if the results were looked at over a number of seasons rather than just one season, as certain applications such as Biplantol and compost may be beneficial to soil fertility and plant health in the long term rather than the short term.

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.