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VintnersSupply_1-3v_VSC_Dec10.qxd 11/10/ GRAPE GRO WING ™ A DIVISION OF MOECKLY ENTERPRISES, INC. FILTRATION & SEPARATION management program was the same the following year (i.e. another 20 pounds of nitrogen was applied per acre), and vine- yard production was only 3 tons per acre, then nitrogen use would be 6.67 pounds per ton of grapes—an increase in nitrogen use per ton of grapes of 67%, a very large variation from one year to the next. and received some interesting responses. One was that growers are used to tracking costs on a per-acre basis, so tracking cost of pro- duction relative to yield is a change from the norm. From my perspective, since growers also track production on a per-acre basis, it is a simple calculation to convert input costs per acre to input costs per unit production. We cannot forget that winegrape growing is a business, and tracking input costs per unit of production is the most direct way to do a cost-benefit analysis of vineyard practices. Depth Media Sheet Filters Membrane Filters Lenticular Housings Cartridge Filter Housings Cross-flow Filter Systems Recessed Plate & Rotary Drum Vacuum Filters Replacement Press Membrane and Filter Cloths Pumps, valves & fittings VINTNERS SUPPLY COMPANY P.O. Box 153 St. Helena, CA 94574 Toll Free 800.366.6809 Fax 707.584.7955 www.vintnerssupply.com 58 WINES & VINES DECEMBER 2012 Is this a fair measure of sustainabil- ity performance of nitrogen use? If yield declined by 2 tons per acre because of some physiological response to weather, then I think it is a good measure. A good nutrition-management program should take predicted crop yield into consider- ation, and in the above example this was not done. However, nitrogen use per ton of grapes may not be a good performance measure if yield was reduced because the winery only wanted 3 tons of grapes per acre. In this case yield is related more to crop thinning than vine physiology. I have to admit that the vagaries of con- tracts from year to year—as well as varia- tion due to weather—provide a challenge to using some performance metrics to manage vineyard performance. Neverthe- less, as long as a grower gets paid by the ton for winegrapes, using performance metrics to measure and manage a vineyard seems like a valid approach. A grower's bottom line is directly re- lated to how much he gets paid each year. Therefore, it makes sense to relate costs of production to revenue from production. Many of the performance metrics are mea- sures of vineyard inputs such as water use, energy use (fuel consumption) and nutri- ents, be they organic or synthetic. The cost of each of these inputs can be calculated to determine the cost of pro- ducing a ton of grapes. The above exam- ple is a good case in point. If a grower is using yield projection as a guide to vine- yard management, then inputs such as nutrients should be altered accordingly to save input costs if projected yield is lower. Moreover, tracking input costs per unit of production is an important guide even if revenue is dependent on contract stipu- lations; revenue is based on tons of grapes per acre, so management inputs should be tracked using the same metrics. I used the above logic with a few growers Another argument against using perfor- mance metrics is best encapsulated in this quote from a grower: "A vineyard is not a factory. I do not grow widgets, I grow Chardonnay." One of the things I have al- ways liked about the wine industry is the romance of it all. The above quote remind- ed me that many growers and winemakers see what they do as different from other growers who produce nut crops, stone fruits or commodity crops. However, we cannot forget that winegrape growing is a business, and tracking input costs per unit production is the most direct way to do a cost-benefit analysis of vineyard practices. The manufacturing industry fig- ured out long ago that figuring production costs per-unit is the most effective. While applying the "factory" approach to winegrape growing may not be roman- tic, it makes good business sense. And if growers talk about their bottom lines, then they should be taking a business approach to analyzing their vineyards' performance. Therefore, performance metrics—particu- larly ones that measure vineyard inputs such as water, energy, nutrients and pesti- cides—will be very important in measur- ing sustainability performance on financial profitability, environmental stewardship and social progress. Dr. Cliff Ohmart serves as vice president of professional services for SureHarvest. He is the author of "View from the Vineyard: A practical guide to sustainable winegrape growing," pub- lished by the Wine Appreciation Guild. Previ- ously he served as research/IPM director at the Lodi-Woodbridge Winegrape Commission. References 1. For more information about the SISC program, see stewardshipindex.org. 2. For more information about the CSWA program, see sustainablewinegrowing.org. 3. groundwaternitrate.ucdavis.edu