- Agronomic: hops
- Animals: sheep
- Animal Production: grazing management, pasture fertility, range improvement, grazing - rotational
- Crop Production: organic fertilizers
- Education and Training: on-farm/ranch research
- Farm Business Management: feasibility study, agritourism
- Production Systems: organic agriculture, integrated crop and livestock systems
- Sustainable Communities: local and regional food systems, sustainability measures
Our conclusion is that raising and using sheep for an integrated approach to weed management, soil enhancement and protein source for food is cost efficient, beneficial, sustainable and economically viable, but only if used for all 3 purposes. It was also so much more fun than using chemicals or power tools!
A USDA supported trip to New Zealand prompted us to look seriously at alternative weed management methods. Weed management is the most difficult part of farming hops organically. Not keeping the plants clear of overgrowth can result in diseased plants and soggy crowns that can inhibit yield.
With the help of a SARE grant, we started with a herd of 13 sheep in June of 2014 (1 ram, 4 ewes and 8 wethers). The ram and one of the wethers were separated from the rest and spent summers at Hillside Homestead B&B, primarily to control the timing of breeding. The other 11 divided time between New Mission Organics and Delight of Life farms. In January of 2015 while overwintering at Delight of Life, one of the wethers passed away (unknown cause; an autopsy was not performed). In June 2015, 6 more wethers were purchased. In July 2015, with the 2 acre test plot expanded to 7 fenced acres, 3 alpaca joined the sheep herd to serve as protectors.
In this our final year of study, we focused on three areas, identified in the objectives section of this report.
Effectiveness of weed control: 7 acres were managed by the sheep herd and 3 acres were left as a control. In the control zone, weeding was performed by migrant labor once and two additional times by the farm owners pulling by hand and using a weed whacker. One thing is very clear, it takes a lot of sheep to do a proper job of weed control. The sheep had a tendency to stay within a 2 to 3 acre zone even though they were free to roam the full 7 acres. We can’t be sure whether it’s because they were rotated in that same zone last year or because they prefer the clover mix cover crop over the perennial pasture mix. We’ll switch cover crops in 2016 to see how they react. We might also use the polywire electric fencing to contain them to a smaller section of the hop yard for periods of time. We’ll also work towards growing the herd. We estimate that 8 to 10 sheep per acre of hops is ideal.
The cost efficiency of the sheep weeding method is amazing. From June to November, the only supplemental feed we gave the sheep was a sweet grain mix ($17 for 50 lbs). At 10 lbs per sheep, we spent less than $2 per sheep the entire hop growing season. Compare this to $500/day for a migrant crew of 4. Four people can weed 2 acres per day and weeding should be done at least 3 times.
10 acres, crew labor = $7500
10 acres, sheep labor (assuming 80 sheep) = $160
Over-wintering, by contrast, is not inexpensive. From my last report, it costs about $95 per sheep to provide hay and supplemental grain from November to April. Without the protein solution (butchering and selling the meat) and if we do not count the value of 6 to 8 lambs born in the spring, the cost to keep sheep for weed management on an annual basis with all costs considered is about the same as hiring a crew 3 times per year for a 10 acre hop yard. The protein sales and lambing are key to beating the breakeven point.
The loss of hop bines due to weed whacker accidents or sheep entanglement or bine biting was about the same at 4 bines per acre (there are 3 or 4 bines per plant and 800 plants per acre). Unfortunately the alpaca, having a very different mouth structure had a bite-through rate almost 3 times as high.
Fertility benefits of sheep and cover crops: preparing the hop yard for sheep inhabitants pushed us to be sure our cover cropping was in and ready by late June. We knew we wouldn’t want to be opening gates and running up and down the rows with a large tractor once the sheep herd was contained inside of the fencing. Ironically, the sheep aren’t able to be in the hop yard when we need them most. It’s the leaf trimming on the lower part of the hop plant that is most beneficial in combating diseases like downy mildew. We are not able to let the sheep begin their pruning until the hop plants are at least 12 feet tall (60% of their final height), or they’ll be chewing on the leaves and side arms that will eventually be the top third of the plant.
Using a Minolta SPAD 502 chlorophyll meter, we were able to confirm that the hop plants in both the control zone and sheep/alpaca enhanced zone never became nitrogen deficient. We were unable to prove using the SPAD test that the hop plants living with the sheep benefited more from the extra fertilization than the control zone. SPAD N results were too similar to show a clear winner.
However, soil fertility testing showed a 5-10% gain in N (nitrogen) in areas where the sheep and alpaca were contained. Petiole analysis was not performed, but will be in a future year.
Diversification of farming operations: With very little competition in Michigan, raising sheep for the purpose of selling the meat is on its own a worthwhile endeavor. Marry this concept with weed management and you have a business model that scratches its own back. We are also seeing an increase in hop yard tours and media contacts, now that we have farm animals. We conclude that the sheep bring a higher agro-tourism and public relations value than the hops alone.