Lake County winegrape growers are committed to sustainable farming that preserves the natural resource base, contributes to local communities, and remains financially sound. They are leaders in the statewide program to promote sustainable winegrowing with over 70 percent participation in workshops to assess the sustainability of their farm operations. Through the Lake County Winegrape Commission, Lake County growers fund and participate in a year round education program in sustainable winegrowing.

Dorn Vineyards

Vineyard near Clear Lake, Lake County, California

     Lake County's ideal climate and altitude support sustainable winegrape production, giving growers here a leg up. Not only is winegrape quality excellent, few pests can tolerate the climate. Winegrapes are grown from lake level (1370 feet) up to about 2,600 feet. This elevation provides cooler winter conditions and a later growing season start than in other California grape-growing regions. Summer growing conditions are suitably warm to ripen the varieties Lake County is famous for, Cabernet Sauvignon and Sauvignon Blanc. Proud of their environment, most growers will mention that Lake County has the cleanest air in the state, and that the elevation allows rapid cooling in the evening.

     Lake County does not have moth pests, and leafhoppers and mites are minor problems relative to warmer growing regions. Lake County also has no confirmed cases of Pierce's Disease, for which cold winter conditions are credited. About 30 inches of rain fall on Lake County every year. Most of this falls during winter months and does not contribute to fungal diseases that occur during the growing season, such as bunch rot.

     Lake County's history and geography form a rich inheritance of vibrant natural ecosystems. Lying in the heart of the northern Coast Ranges, Lake County cannot be reached by interstate freeway, railroad, or DC10. A catalogue of Lake County land use shows 94 percent in native vegetation or water surface area, three percent in urban, residential and industrial uses, one percent in vineyards, and two percent in other agricultural uses.¹ At the county's center is Clear Lake, the largest naturally occurring lake in California with a surface area of 60 square miles. Lake County wildlife includes the largest North American rookery of Great Blue Herons, conspicuous herds of Tule Elk, and a fabulous array of migratory waterfowl that seasonally inhabit the Lake and surrounding wetlands.

Ron Keas

American White Pelicans on Clear Lake

What is Sustainable Winegrowing? Agricultural systems include the communities and ecosystems around them, all of which must be sustained for the long term. The California wine industry has defined three sustainability principles as "The three E's", Environmentally Sound, Socially Equitable, and Economically Feasible.2 Sustainable winegrowing requires a systems perspective. For example, at the farm level growers must integrate management options for pests, fertility, irrigation, and crop level because all of these areas influence each other. At the ecosystem level growers consider watershed health, wildlife habitat, and biodiversity.

     Lake County winegrowers use a variety of farming practices as part of sustainable farming systems. Because every site has a unique combination of soil, slope, microclimate, surrounding ecosystem, and winegrape variety, these practices vary from vineyard to vineyard.

     Soil Management   A healthy soil provides provides vital nutrients, moisture, aeration and drainage to sustain farming. Organic matter and soil microbes contribute to these soil characteristics, and Lake County's knowledgeable growers build soil organic matter and support soil microbial communities with the use of compost, manures, and cover crops. In hillside locations growers must be careful to prevent erosion and preserve the topsoil. No-till farming, cover cropping or maintaining straw cover over soil in the winter, and use of structures to safely convey water off-site, prevent the loss of soil while maintaining a healthy watershed and lake ecosystem.

     Fertility Management  Healthy and productive vines sometimes require the use of fertilizers, whether as compost, manure, and nitrogen-fixing cover crops, or as mineral fertilizer. There are several ways growers apply fertilizers carefully in order to avoid water contamination and reduce costs. Compost, manure and cover crops have the advantages of providing organic matter along with the slow release of nutrients to vines as microorganisms decompose or "chew up" the materials. Mineral fertilizers are frequently dissolved and applied through the drip irrigation system. This allows growers to match fertilizer application with vine nutrient uptake and to apply the fertilizer in the area where vine roots are most active. The nutrient with the greatest potential to leach and contaminate ground water is nitrogen. Fortunately, grapevines require very little nitrogen, and in some vineyards nitrogen is seldom, if ever, applied.

Red Hills Vineyard

Crimson and Rose Clovers provide soil cover, nitrogen and beneficial insect habitat in this vineyard

     Cover Crops   Cover crops are low-growing plants grown between vine rows. They can prevent soil erosion, serve as refuges for beneficial insects, contribute soil organic matter to soil, provide nitrogen, increase soil porosity, and increase or decrease vine vigor. On Lake County hillside vineyards re-seeding clovers and grasses are used because they provide soil cover and organic matter and do not require annual tillage. On valley locations a range of cover crops are used, for example mustards to discourage root-feeding nematodes, oats and nitrogen-fixing legumes to build up soil organic matter, and fescues to limit vine vigor.

     Pest Management   Growers use Integrated Pest Management (IPM) principles to minimize the health, economic, and environmental risks of pest management. The IPM approach requires an understanding of the life cycles of the crop and pest. Growers use a combination of management tools including pest resistant plant material, and cultural, biological, and chemical controls. Pesticides are not applied on a calendar basis, but according to the dictates of the pest's life cycle.

     Not all chemical pest control materials are equal. For example, oil, soaps and garlic can be used as pesticides. In winegrape production about 85% of the material applied for pest control is sulfur, a naturally occurring element with low toxicity. When comparing materials other than sulfur, Lake County winegrowers use a lower percentage of potentially risky materials compared to other winegrowing regions in the state.³

Devoto Vineyards

As part of an IPM program, this grower uses tillage in the vine row to control weeds

     Irrigation Management   Most Lake County growers use drip irrigation systems, which cause less evaporation and water run-off of than do sprinkler or flood systems. In addition, the finest winegrapes are grown by deficit irrigating, that is, applying less water than the vines could potentially use. In Lake County winegrapes use only 3-10 inches of applied water per year, compared to 30 inches for a high water use crop such as irrigated pasture.

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