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May 2015 P R A C T I C A L W I N E R Y & V I N E YA R D 81 May 2015 P R A C T I C A L W I N E R Y & V I N E YA R D 81 G R A P E G R O W I N G inches]) and directly under vines. These instruments allowed us to capture sulfur movement in drainage waters during irrigation and storm events. Tension lysimeters (vacuum applied) were sampled for soil water during long irrigation events and dormant season storms when the soil was saturated, and zero-tension lysimeters (no vacuum), were sampled for leachate during four-hour irrigation events when the soil was unsat- urated. 11 Precipitation, irrigation water, soil water and leachate samples were ana- lyzed for SO 4 2- and total dissolved sulfur (organic plus inorganic forms). Major findings At the St. Helena site, the immediate chemical reaction of applied sulfur on the soil surface was evaluated using 1) XANES spectroscopy results, which allowed determination of all chemical forms of sulfur present in soils, and 2) direct measurements of soil pH, SO 4 2- and total sulfur. Following each of two applications of 6.7 kg elemental sulfur per hectare (6 pounds per acre) to the vineyard, the majority of sulfur applied oxidized to SO 4 2- during the first 30 minutes. Soil pH decreased as the oxidation process gen- erated acidity, and SO 4 2- within surface soils increased. Following each applica- tion event, pH returned to pre-applica- tion levels, and SO 4 2- transformed into the dominant organic form of sulfur measured in vineyard soils. Because the first part of the study showed that applied sulfur transforms into SO 4 2- and organic sulfur, which are both mobile in the soil, the next objective was to understand where these sulfur forms go within the vineyard. Do they stay within the field in vine tissues and soil, or are they moved by water off-site? Understanding the pathways of sulfur within soils, vegetation and water path- ways is called developing a sulfur bud- get, which we calculated at the Napa, Calif., vineyard. The total sulfur content of vegetation tissues was a relatively small component of the vineyard sulfur budget. During the growing season, sulfur concentra- tions in vine tissues were 2 ± 0.2 g kg -1 dry tissue and in grapes were 0.4 ± 0.1 g kg -1 dry tissue; together these account for 7 to 14 kg sulfur per hectare (6.2 to 12.5 pounds per acre). During the dormant season, sulfur con- centrations in cover crop tissues were 2.3 ± 0.1 g sulfur per kg dry tissue, constitut- We like to think that Vintage Nurseries does many things well, but listening to our grower partners is the one that makes us proudest. In fact, it's the reason we've committed to invest millions of dollars for facility upgrades, improved procedures, and innovations to beneft the industry as a whole. You'd be amazed at all of the improvements from our newly improved grafting facility with temperature control and sterilization upgrades to quality control, production and customer service…the result of talking to growers like you. So check out the "new" Vintage Nurseries, where our success is built around the promise of your success. WASCO 661-758-4777 PASO ROBLES 805-237-8914 SANTA ROSA 707-542-5510 TOLL FREE 800-499-9019 www.Vintagenurseries.com serVing the wine, table grape and raisin industries "Growers First" Isn't Just A Slogan, It's A Promise. See All That The "New" Vintage Is Doing For You Toll-Free: 877-552-4828 909-464-1373 • Fax: 909-464-1603 For your nearest dealer, contact: Quick and economical, this long-lasting dripline holder can be installed in seconds. The built-in saddle prevents water flow restriction. Available in 1/2" and 7/8" sizes. Patent No. 4,615,140 DRIPLOK™ WinVineDripLok AD.qxp_Layout 1 12/1/14 2:52 PM