Evaluation of Wine and Table Grape Cultivar Performance on REclaimed Surface Mined Land in Eastern Kentucky

Increased awareness of viticulture in Kentucky has raised the need to evaluate the suitability of wine and table cultivars to the state's climate. Vineyard acreage in the state increased by three-fold between 1999 and 2002, mainly due to the changes in the state's tobacco program. The 2002 Grape Grower's Survey projected a total of 311 acres of vineyards to be planted by 2004. The major limitation to expansion of viticulture in Kentucky is the continentality of the macroclimate. Annual row crop production in eastern Kentucky is practiced in the fertile river valleys. However, there are many reclaimed surface mine sites at higher elevations that are not readily suited to annual row crop production. Macroclimate maps are helpful in defining regional basis of vineyard suitability, but these maps tend to be too general to exactly match cultivar to vineyard sites. The topography of a given site including absolute elevation, slope, aspect and soil properties greatly affect the mesoclimate of a site. The 'Laurel Fork' site at the Robinson Station has a relative elevation advantage of746 feet compared to the surrounding areas. Under radiational cooling conditions, with calm winds and clear skies, the earth loses heat to space and cools the adjacent layer of air. If the vineyard site is on a slope the relatively cool air moves downhill and the sinking cold air displaces the warmer air to higher elevations producing thermal inversions. This phenomenon of thermal inversions is typical in eastern Kentucky due to the varied topography of the region. Grapes need to be planted on soils with good internal water drainage. Grapes require moderately fertile soils. Therefore, for reclaimed surface mine soils, grapes need to be planted on raised beds that have been sub-soiled. Viticulture is economically feasible only in areas where risk of winter and spring freezes is minimized and where the cultivars in high demand can be sold for a farm-gate value approaching $lOOO/ton (2002 Grape Cost Return Estimates). The primary end-users for wine grapes are wineries. Table grapes are marketed at Farmer's Markets and at local stores and restaurants. According to the New Crops Opportunity Center publication on grapes a conservative return estimate for table grapes is $3224/acre.