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80 P R A C T I C A L W I N E R Y & V I N E YA R D May 2015 80 P R A C T I C A L W I N E R Y & V I N E YA R D May 2015 G R A P E G R O W I N G collected and analyzed for pH, extract- able SO 4 2- and total sulfur. Additionally, the forms of sulfur pres- ent in the soils were determined using X-ray absorption near-edge structure (XANES) spectroscopy. Soil samples were collected for these analyses 30 min- utes prior to elemental sulfur applica- tions, and at 30 minutes, two days, seven days, 12 days and 19 days after each application. Movement of sulfur into soils, vegetation and hydrological pathways at a Napa, Calif., vineyard The vineyard block used in this part of the study has Bressa-Dibble clay loam soils (0–0.4 meters, or 0-1.3 feet) under- lain by a sandy clay hardpan that is consistent across southern Napa Valley and predates vineyard cultivation. Vines are Dijon 114 Pinot Noir grafted on 101-14 rootstock, planted in rows perpendicular to the slope with 1.8 meters (5.9 feet) spacing, and were 14 years old at the time of this study During the dormant season, growers seed vineyard avenues with cover crops such as Rosa, Trifolium and Triticale spe- cies. Soil sampling was conducted Oct. 19-21, 2005 (after harvest), and April 9-11, 2007 (after the dormant season), to char- acterize soil physical and chemical prop- erties within a vineyard block. Six cores (2 cm diameter x 1.2 meters depth [0.8 inches x 4 feet]) were collected in four 30 cm (11.8 inch) sections. Sulfate and total sulfur were measured in these samples. Vine leaf and grape tissues were col- lected Aug. 22, 2007, immediately prior to harvest, freeze-dried, ground and analyzed for total sulfur content. Total leaf and grape production data were used to scale total sulfur contents of vine and grape tissues to the hectare. 19,20 Immediately prior to mowing on March 15, 2005, cover crop tissues were har- vested from 0.5 meter 2 (1.6 feet 2 ) areas randomly located within the vineyard study block. Samples were dried and weighed to determine dry mass per area, and subsamples were analyzed for total sulfur. Across the study area, two types of soil water collectors (lysimeters) were installed below the majority of the root- ing zone (0.36 ± 0.01 meters [14.17 ± 0.39 Component kg S per hectare* Soil gain/loss† Growing season Sulfur applica ons 105 + Irriga on water 21 (1) + Vine leaves 5-11 0 Soil (0-0.5m) 1,623 (354) 0 Wine grapes 2-3 - Leachate 4 (1) - Dormant season Precipita on 1 (0.5) + Cover crop 4-10 0 Soil (0-0.5 m) 981 (526) 0 Soil water 123 (40) - Annual inputs 127 (1) Annual outputs 129-130 (40) Table 1. Annual vineyard budget measured in Napa, Calif. (Data originally appeared in reference No. 20.) *Total sulfur (S) is expressed as mean values (± 1 SD), except for biomass estimates, which are expressed as a range. †+, -, and 0 denote gain, loss and no change.