Grape Grazing

An innovative system in California incorporates sheep into the vineyard

American philosopher and futurist Buckminster Fuller said, “You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete.” 

Contemporary viticulture, like much of agriculture, is dominated by systems that adhere to a status quo. The same default models are implemented in wildly different contexts, and efforts to design vineyards appropriate to the specific needs of a site are rare. In this one-size-fits-all approach, change for the better tends to be incremental, accomplished by adopting practices that minimize impact, such as reducing tillage or substituting less-harmful inputs. Yet the structure of the designs has remained the same, and therefore the outcomes have as well: biodiversity is suppressed, soil health declines, soil water holding capacity and carbon retention decrease, and profitability is increasingly difficult to maintain as the necessary quantity of inputs and their costs increase. 

By relying on this approach of incrementally improving the default models, we risk becoming stuck, as our attempts at significant change result only in perpetual tweaks to a fundamentally faulty system. The existing designs were constructed with a narrow focus that did not look beyond maximizing production and profit. Reaching beyond those aims necessitates the creation of new systems. 

To break out of the default mode of agricultural management, vital questions must be asked: how do we create new models for farming without perpetuating past mistakes? More specifically, can we design farming systems and create management strategies that simultaneously restore health and biodiversity to the ecosystem while also increasing agricultural productivity and profitability while improving working conditions? 

Vineyard Establishment

In 2014, I was given a unique opportunity to implement a viticultural design concept by establishing and managing a new vineyard at Paicines Ranch, located on the central coast of California. This project was guided and contextualized by a specific question: how can we collaborate with nature to restore biodiversity, soil health, resiliency and beauty to a site while producing healthy and profitable crops? The project was further guided by the criterion that the design should allow for grazing by sheep at any time of year. This last element was essential due to early success with grazing sheep through the growing season in conventionally trellised vineyards modified for this purpose.

From 1965 to 1995, Paicines Ranch was home to 1,000 acres of wine grapes, in large part planted on low, flat terrain, subject to frequent spring frost. The vineyards were imposed on the landscape with scant thought given to working with the ecological patterns, climate and topography of the site. All the original plantings had been ripped out before I arrived at the ranch.

With the guiding context always in mind, the vineyard site was selected primarily based on indicators from the surrounding landscape: vegetation, soils, slope, aspect, wind patterns, access to water, previous farming history, distance from headquarters and suggestions from an older employee who had been on the ranch for 30 years. A hilltop location with mostly north-facing slopes was selected, as the native perennials (trees, grasses, shrubs, etc.) in this environment are naturally more abundant on slopes with a north-facing aspect on account of the less-severe sun exposure and better water retention. 

In preparation for establishment of the vineyard, a single light application of compost was applied to the roughly graded surface of the site. During the first three years of development, the vineyard site was grazed using holistic planned grazing. Cattle were used in the first years, and sheep were introduced in the third year, just before planting. The carrying capacity of the land increased from seven animal days per acre in the first year (which saw an application of compost, but no cover crops) to over 70 animal days per acre by the third year, after mixed species grazing and the seeding of a diverse cover crop blend. The outcome of these practices was a significant increase in soil health and productivity before the first vines were planted, an accomplishment achieved primarily through a change in management practices.

During this preliminary phase of improving soil health, we investigated several kinds of trellis that would allow sheep to graze the vineyard at any time of the year. The ideal trellis would meet three main criteria: 1) the fruiting zone would be above the browsing height of tall sheep (factoring in their ability to briefly stand on their back legs to reach leaves); 2) the trellis would not be too tall for ease of pruning, training and harvest; and 3) the trellis would provide total or partial shade to the vineyard floor. Although we planned to harvest by hand, we also sought out a trellis system that could be mechanically harvested, as that has become an increasingly common practice in the industry.

Ultimately, we settled on a high V-trellis system designed by Jerry Watson in south Texas. Although the Watson Trellis was not developed with year-round sheep grazing in mind, it has proven to work exceptionally well for this purpose. The elevated trellis and irrigation wires in the Watson Trellis system allow for easy access in any direction for both sheep and humans, enabling the construction of temporary livestock fencing throughout the vineyard. The partial overhead canopy provides dappled shade and cooler temperatures during the heat of the day, an effect that is beneficial for grapes, sheep, humans and plants on the vineyard floor. On account of its height, the system also reduces the risk of frost damage, a contributing factor to its strength in the face of increasing climate variability.

Another advantage of a sheep-friendly trellis design is that it enables sheep to sucker and shoot-tip the vines as they graze. This eliminates the need for hand or machine suckering and pruning, while having the additional benefit of cycling the nutrients from the plants back into the soil. Targeted browsing of vines also appears to contribute to increased Brix levels of vine leaves when compared to areas excluded from sheep grazing (dung and urine left behind by the sheep likely contribute to this effect). 

After the trellis had been determined, we laid out the row orientation. The prevailing wind at the site consistently blows from the same direction. In order to avoid the “comb-over effect,” by which the shoots are pushed to one side of the V, the vineyard was oriented so that the wind would blow down, not across, the rows. That meant the row direction would be roughly north to south, which necessitated that the rows be oriented up and down (rather than across) a moderately steep hill. Despite this orientation, the vineyard has never experienced any erosion problems. This can be attributed to the fact that the vineyard is managed without the use of tillage, and the ground is consistently covered with plants and plant litter.

The climate in our part of California is Mediterranean, with hot, dry summers and rain historically occurring from October through early April. The general climatic trend is toward hotter and drier conditions; therefore, we selected wine grape varieties that have proven to do well in hot, dry climates. The varieties we have planted include Grenache, Syrah, Cinsault, Counoise, Nero d’Avola, Mencia, Barbera and Ciliegiolo for reds, and Assyrtiko, Verdejo, Fiano, Picpoul Blanc, Muscat Blanc and Grenache Gris and Blanc for whites. Most of the vines are grafted onto 1103P rootstock, with a few rows using 110R. Both rootstocks are vigorous and do well in dry conditions.

A primary aim of this vineyard design is that it can be grazed at any time of the year once the vines have grown up to the cordon wire (approximately 66 inches tall). In our vineyard, this has taken anywhere from one to four years; slow training time has generally been due to squirrel damage. The ability to graze at any time of year substantially shifts management away from practices with high input costs, such as applying fertility supplements, use of machinery (in the forms of tillage, mowing, herbicides, shoot tipping, etc.) and hand labor practices like weeding and suckering. The shading effect of the overhead canopy also creates a cooler work environment for those tasks that still need to be done by hand, such as shoot thinning and harvesting.

Benefits to Sheep/Grape Integration

The vineyard at Paicines Ranch was not designed to replicate the reductionist, mechanical and chemical approach to contemporary viticulture, but rather to mimic natural processes while implementing design elements that allow sheep to perform many of the tasks necessary in viticulture. In designing this approach to integrating grazing in vineyard management, we did not think of grazing sheep merely as a substitute for any one part of typical management practices (a mower, for example), but instead as a new process with an active, multivalent, and beneficial role in the vineyard system. In practice, this means sheep can perform all vine suckering, shoot tipping, nutrient cycling, and grazing/browsing while simultaneously improving fertility (including vine Brix), soil carbon levels, and water infiltration. Furthermore, these benefits are gained by use of a practice that does not negatively affect beneficial insects, increases plant diversity, is powered by sunlight, and supports another revenue stream. 

Here is a brief rundown of some of the benefits that have been realized in this vineyard by the time of its second harvest:

• Soil organic matter has increased from an average of 1.5 percent in 2014 to 2.5 percent in 2021.
• Plant diversity is continually going up: as of 2022, the vineyard was home to 56 species, many of which are natives. This has reduced the need to seed cover crops, and no cover crop was seeded in 2022. Over 60 species of birds have been seen in the vineyard, several of which have nested here, including western bluebirds, tree swallows, barn owls, mourning doves, and northern harriers. In 2022, the vineyard saw a seasonally resident breeding flock of 800 tri-colored blackbirds (an endangered species) forage in the vineyard each day. The vineyard is an eBird hotspot.
• A 2021 comparative insect study with a neighboring conventional vineyard showed five times greater overall insect abundance and two to three times greater abundance of beneficial predator and parasitoid insects in the Paicines Ranch Vineyard, while pest species were at the same level. No pesticides are used in our vineyard. 
• No water runoff or erosion has ever occurred in the vineyard, even from heavy rainfall events including recent (2023) flooding.
• Grape yields and forage capacity are progressively increasing, demonstrating effective double cropping at the site for meat and wine grapes. 

The economic savings from this regenerative approach to winegrowing will vary between vineyards, but based on previous research and current farming costs, we estimate a yearly savings of $1,000 per acre (not including the sale of any livestock). The savings can be traced to a significant reduction in tractor and fossil fuel use, labor and fertility inputs. The cause of these savings can be easily visualized: rather than mowing, tilling or spraying the vineyard floor (which would require numerous tractor passes, entailing labor and fuel costs), sheep graze the plants, cycle the nutrients back into the soil and generate income in the process. Supporting the ecosystem to function in this way encourages biodiversity, carbon cycling and soil health.

The entire grape crop from the vineyard is sold to regional winemakers, as the ranch does not have its own winery. Demand for our fruit has exceeded supply and we maintain a growing waiting list. We work specifically with winemakers who focus on sourcing fruit from vineyards that use organic, biodynamic or regenerative organic practices. These winemakers have become partners in sharing our mission, practices and story with the public. In turn, we promote their wines to our meat customers and ranch visitors.

The vineyard at Paicines Ranch is an ongoing experiment in the possibilities of using holistic design and management to profitably restore biodiversity, health and beauty to the ecosystem. There are countless possibilities for creatively working to realize the potential of working with nature; this article describes just one example of such a collaboration. Each site is unique, as are the land stewards’ vision and mission. Having a clear understanding of a site’s context and creating a design and practice to achieve a given mission is a powerful tool, but the nature of the design will necessarily vary from site to site. 

Humanity’s most profound impact on the earth’s landscape has been brought about through our agricultural practices. This impact has been primarily negative. If we are to reverse the unintended but devastating consequences of our intervention, we need to adopt frameworks of design and practice based on ecosystem health, beneficial intention, creativity and reverence for all life. Such an approach offers the chance to turn agriculture into one of the most powerful means for restoring health and biodiversity to the world. 

Kelly Mulville is the vineyard director at Paicines Ranch Vineyard. Learn more at paicinesranch.com/our-work/vineyard.