A good vineyard manager encourages a balance between vine growth and fruit production achieved through pruning and soil nutrition. Dr. Paul Domoto, pomology and viticulture researcher and fruit extension specialist at Iowa State University, presented at the 2012 Eastern Viticulture workshop in Mystic CT.
Understand a field’s crop history to ensure residual herbicides will influence grape vines’ health and vigor. Previously grown alfalfa leave soils too high in Nitrogen. Before planting grapes, grow an annual crop to utilize that Nitrogen. Old vegetable fields often have excess levels of Potassium or Phosphates.
Start with a good soil test. Use the USDA–NRCS Web Soil Survey to determine the areas on your field with various soil types. Determine soil drainage characteristics of each area. Run a separate soil test for each soil type, grape type and/or treatment plan. (i.e. irrigation, fertilizer programs, etc.) Collect soil samples at two depths, the top 6 to 8” and another sample of the parent material 12 to 16” deep. Tell the lab your intended crop and cultivar; request organic matter as well as micro and macronutrient analysis. [more]