Evaluating sheep as a sustainable approach to reducing reliance on herbicides, fungicides, and commercial fertilizer in hop yards

Project Overview

Project Type: Farmer
Funds awarded in 2015: $6,954.00
Projected End Date: 12/31/2015
Region: Northeast
State: Maine
Project Leader:
Peter Busque
The Hop Yard
ryan houghton
The Hop Yard

Information Products


  • Agronomic: hops
  • Animals: sheep


  • Pest Management: biological control

    Proposal summary:

    The Hop Yard would like to research the effectiveness of grazing sheep on mature hop plants during the latter parts of the growing season (July to early September) to reduce reliance on conventional weed, pest and fungus control methods.  We will work with Northstar Sheep Farm in Windham, ME to introduce mature animals into our yard and observe and measure their effectiveness.

    The goal will be to reduce labor, materials costs, and potential groundwater effects from applying conventional controls while maintaining or increasing effective yields. In addition, creating a dual-use property with a net positive impact on both crop and herd.  We will then share the results of our research via our various social media outlets, our blog, and by presenting at the UVM hops growers conference.

    Project objectives from proposal:

    We propose to graze 10-30 sheep on our mature, third-year hop plants once the plants have reached their maximum height for the season (typically July 4th) and their bines have thickened to the point where the sheep will not be able to damage the plants.  We will segment a large portion of our 2 acre yard in Gorham, ME into quadrants which will allow us to move sheep throughout the yard as they exhaust edible material and also allow us to have a control population of plants to measure and observe differences.

    We will follow our normal process for growing hops from emergence in April until the bines are ready for our traditional stripping and manual weed management processes.  This involves crowning and pruning plants, installing coir twine, training bines on twine, applying nitrogen and other fertilizers, tilling rows, and other early season tasks.  

    We currently have two large trellises on our Gorham farm; a two acre structure installed in 2013 and a six acre structure installed in 2014.  Hop plants take three years to fully mature and reach their full production capability and the plants on our two acre trellis are entering their third year.  We will use the two acre trellis as the area for this study.  The two acre trellis is currently planted with 50% Sterling variety hops and 50% Nugget variety hops.

    In May we will install temporary fencing on a significant portion of the two acre trellis across both hop varieties.  We will create at least two separate grazing areas in the yard for the animals; one on each variety.  We will also create a third holding area for the animals so we can move them out of the yard when normal maintenance activities need to happen.  This will allow us to use a rotational grazing approach to manage the impact on the hop yard and plants while ensuring access to adequate feed for the sheep.

    June is typically the time we would focus our activity on stripping the lowest three feet of leaves and lateral branches from the trained bines.  

    On June 1st we will document the current weed population and undergrowth (sucker and leaf) status as well as the diameter and height of existing bines on both grazing areas and the remaining portion of the trellis that will serve as our control.  We will also take soil samples from both experimental grazing areas and the control area and send them for analysis. Additionally, we will use a penetrometer to monitor differences in soil compaction within the areas.

    We will weigh and document the general physical condition of 20 animals and then introduce them into grazing area and variety one.  Over the first seven days we will observe and record the positive and negative effects of the animals on the bines, weeds, and low leaf / lateral (sucker) growth.  We will continue our typical management processes on the control area.

    If we observe negative effects such as bines being damaged or destroyed by the animals we will move the animals to the holding area until bines can further mature.  We will then reintroduce the animals on or around July 1st.

    Assuming we do not observe any negative effects to the bines we will then rotate the animals to grazing area and variety two.  We will then rotate the animals through the two grazing areas on a weekly basis through the end of August.  We will observe and record the weed population and undergrowth status every two to three days throughout the growing season.  If we observe that the animals are consuming too much or too little of the vegetation during the one week rotations we will add or remove animals as necessary.  The animals will be removed 7-14 days prior to harvest.  

    In September we will send hops of each variety from both the experimental areas and control area for alpha acid, beta acid and essential oil content.  We will also collect and send new soil samples from both experimental areas and the control area.  During harvest we will record the total number of harvestable bines and the total weight harvested in the experimental areas and control area.

    Summary of Data Collection:

    June 1st - Soil samples from grazing areas and control.  Weight and general physical condition of animals used for research.  Observations of weed population and undergrowth.

    June 1st through August 31st - Observations of weed population and undergrowth and overall consumption rate of animals.

    September 1st - Weight and general physical condition of animals used for research.  

    September 10th - Count of bines suitable for harvest and total weight of harvested cones.  Analysis of alpha acids, beta acids and essential oil content of crop from experimental area and control area.  Soil samples from grazing areas and control.

    May 2015 - The Hop Yard will purchase supplies for fencing (8 hours).  A third party contractor will construct fencing (40 hours).  The Hop Yard will conduct outreach via blog and social media (4 hours).

    June 2015 - Northstar Sheep Farm will weigh and transport sheep and introduce them to grazing areas (8 hours).  The Hop Yard will collect soil samples and submit for analysis (4 hours).  The Hop Yard will conduct outreach via blog and social media (4 hours).

    June - September - The Hop Yard will rotate sheep through grazing areas (16 hours).  The Hop Yard will document observations of animal impact on weeds, pests & fungus (16 hours) .  The Hop Yard will conduct outreach via blog and social media (8 hours)

    Sept 2015 - The Hop Yard will harvest hops from experimental and control areas (24 hours).  The Hop Yard will measure yield of control areas vs experimental areas (4 hours).  The Hop Yard will collect and submit soil samples & hop samples for analysis.  (4 hours).  

    Nov 2015 - Final report, video of practices and results,x` outreach via blog and social media.

    February 2016 - Present findings at UVM Hops Conference in Burlington, VT.

    Our farm has a significant social media presence and substantial traffic to our website/blog.  Our project progress and findings will be shared with 1200 Facebook fans, 600 Instagram followers, 500 twitter followers and the hundreds of monthly unique visitors to our website/blog. Donna Coffin has also committed to sharing results within her farming newsletter, which reaches 640 people per publication.

    In addition we will present the findings of our research at the annual UVM Hops Conference in February.  There are typically over 200 individuals in attendance that are either active hop growers or interested in becoming growers.

    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.