Organic Vineyard/Orchard Weed and Grass Management Using Miniature Sheep

SUMMARY

We sought to demonstrate and measure the benefits of using an heirloom breed of miniature sheep (Olde English Babydoll Miniature Southdowns) to maintain organic vineyard and orchard floors, while specifically measuring their cost-effectiveness against more labor-intensive weed/grass management methods. Adult miniature Southdowns are 24 inches or less at the shoulder without wool, which is the reason we selected this breed. They can’t easily reach the canopy of most grapes.

OBJECTIVES

1) To analyze the cost benefits of using miniature sheep versus mechanical methods for weed control in organic vineyards and orchards.
2) To demonstrate a unique, sustainable farming practice that may encourage more growers to move to organic methods.

RESULTS

Beginning in August 2004, I met with the Fetzer Vineyards team several times over six months to discuss details of the study. I selected Fetzer because of its national reputation as a leader in organic/biodynamic wine production, and because of the expertise of one of their employees in conducting scientific research.

We decided to conduct trials of both low-density (3-4 sheep per acre) and high-density (7-8 sheep per acre). We divided the study block into six sections using temporary electric fencing. With the help of grant funds, Fetzer purchased 2,750 feet of Intelitwine (between rows) and ElectroNet (perimeter) fencing and used it with a solar fence charger.

As vineyards cover crop through the heavy winter rains, we selected mid-February as our target date, when the cover crops would be mechanically cut and disked into the soil. On February 22, Ann Thrupp from Fetzer and I took soil samples and grass clippings from each of the six study blocks to be able to analyze compaction and composition of plants with a borrowed penetrometer.

Twenty-four miniature Southdown sheep were brought into the vineyard and placed within the four blocks for sheep, with eight in each of the two blocks designated as “high density” and four in each of two blocks designated “low density.”

The Intelitwine electric fencing proved of little value as the sheep easily jumped over or ran under it. During the study, vineyard workers herded the sheep back into their respective blocks on a daily basis, not a sustainable practice. However, this separation attempt was done strictly for the study and would not be the standard practice in a normal application. The ElectroNet perimeter fencing worked fine, as long as it was charged.

For the next five weeks, the sheep did their job beautifully. The vineyard floor grasses and weeds in lower density blocks were maintained at an acceptable level. In the higher density blocks, the floor was maintained at an optimum level for the short duration of the study.

All went well until “bud break,” a little over one month into the study. In the higher density blocks, the sheep began tasting a few of the new buds on the vines. Although this possibility was discussed prior to the start of the study, the situation concerned the vineyard managers enough that they moved the sheep out of the vineyard. Then, while the sheep were in a “holding” area, coyotes attacked and killed two of them. I came quickly and retrieved the rest on March 26, 2005.

On March 28, 2005, I delivered 12 miniature sheep to Michel Schlumberger Vineyards in Healdsburg, California, for grazing on a hillside vineyard of approximately 4 acres. Because of the steepness of the vineyard, mechanical weed management was quite a challenge, so the owners were eager to try the sheep. They said the following about the experience:

“Since we don’t use any herbicides and we have permanent cover crop, it seemed like this would be a perfect fit. It was. The sheep kept their little heads down and ate and ate until it looked like the 18th fairway. . . . We had twelve sheep and we kept them for a couple of months and they did their job perfectly. The cost of running the sheep for those couple of months cost less than sending a hand crew through. Plus, the additional fertilizer was perfect for our benchland vineyards. Put them in early and get them out at bud break to avoid any of those mysterious missing buds.”

BENEFITS/IMPACTS ON AGRICULTURE

1) The sheep do an excellent job of maintaining the vineyard floor—keeping weeds and grasses clipped to within 1 or 2 inches, depending on how often they are moved. They were also observed eating the unwanted vine suckers, effectively eliminating another costly and labor-intensive job.
2) The manure they deposit offers an additional benefit in improving soil nitrogen.
3) Smaller hooves and the weight of the miniature sheep kept the vineyard floor from being compacted as it would have been by mechanical weed management.
4) The social impact cannot be overstated. From vineyard workers to visitors to the winery tasting rooms, the little sheep hard at work in the fields were a tremendous draw and created enormous goodwill for the wineries.
5) Economically, it makes sense if the sheep are purchased rather than leased, although leasing affords the vineyard a chance to assess the success of the sheep without the upkeep. According to Fetzer Vineyards, the cost for chopping, mowing and Clemens work is approximately $300-$350 per acre per year. At a leasing rate of $1 per head per day at a density of 3-4 sheep per acre, that would compare to $180-$240 for the two months of grass growth prior to bud break. There are additional benefits of fertilizer, attraction of visitors, etc.

PRODUCER REACTION/ADOPTION

The owners of the Yorkville Cellars in Yorkville, California, where the sheep grazed in the spring of 2003, were very satisfied with the outcome because the sheep mostly kept their heads down and roamed the pastures instead of foraging for leaves.

At Fetzer Vineyards, I interviewed the vineyard workers about the sheep as they were being placed in the vineyards. They were enthusiastic about them, saying they were a “good idea” as long as they stayed in the fences.

Last year I sold five of the miniature sheep to a vineyard in Half Moon Bay, California, where they are now grazing. This year I sold seven sheep to another vineyard in southern Monterey County, California. I have reservations for lambs from vineyards in Carmel, Montera and Windsor, California, and requests for late winter leasing from Michel Schlumberger and two vineyards in the Healdsburg area and one in the Napa Valley.

RECOMMENDATIONS

More investigation is needed with these animals and their economic impacts. We didn’t compare the cost/benefits between leasing and purchasing the sheep. I would like to see an extensive cost-comparison against mechanical weed and grass management in orchards—which would have significantly broader organic application in an area of farming where margins are being squeezed to the point of insolvency for many orchards.

I also believe they may be useful in a controlled grazing environment such as grazing organic lavender fields and for small farm row-crop production.

Finally, the additional economic viability of the sheep can be studied. Using their wool for organic products is something I am exploring, and I would like to continue to develop that market. “Dirt” wool, the waste from shearing, can be used as mulch in berry patches.

OUTREACH

1) In November 2003, I spoke to over 100 winegrowers at the University of California Cooperative Extension Organic Winegrowing Short Course about miniature sheep. There was a great deal of interest. It was through that appearance that Fetzer Vineyards contacted me.
2) In February 2004, my ranch was featured on a nationally aired HGTV program titled 50 Ways to Save the Planet, hosted by Nell Newman of Newman’s Organic.
3) In July 2004, my sheep were featured in an article in Gourmet magazine.
4) In July 2004, a feature article on me appeared in Fortune magazine.
5) I sent a press release on the two feature articles that was picked up by all of our local press.
6) In September 2004, following the awarding of the SARE grant, I sent another press release which was picked up by local press
7) In February 2005, I attended the EcoFarm Conference in Monterey, CA, attended by over 1500 organic farmers, producers and educators. I mentioned the study in any of the applicable seminars I attended to great interest.
8) In March 2005, Canvas Ranch participated in Michel Schlumberger Winery’s Barrel Tasting event. I had two of the sheep at the event, along with posters explaining their use as “miniature lawnmowers” in vineyards. About 1200-1300 people attended.
9) In March 2005, the sheep and I were featured in an article in the Santa Rosa Press Democrat with a circulation of 80,000.
10) In August 2005, Canvas Ranch was featured in an 8-page article in a national magazine $1,000,000 Blueprint.