Winter and Spring in the Northeast --- Vineyard Water Holding Capacity

Spring seems to be accelerating into summer. It was such a beautiful day today, but we will be seeing temperatures in the high 40s by the end of the week. I wonder what these unusually warm temperatures are doing in the vineyard?
One thing that is of concern to me is that there hasn't been that much rain or snow during the winter. We have soils that are sandy loam and I'm not sure that they are at field capacity. We do have a substratum at about 3 feet that is hardpan clay so we do intend to tile our land so that the grapes do not have "cold feet". I was asking my husband, what happens in a year like this year where there has been little rain or snow, what would tiling do to the water holding capacity of our soil? I found the answer and a great table at the following site: The Basics of Vineyard Site Evaluation and Selection. Drainage tiles do not reduce soil water holding capacity, but rather remove excess water. So even in well-drained soils, this is not going to lead to more frequent drought stress.
The water holding capacity of a soil is the product of soil texture (water per unit of depth) x depth of soil (or the depth or rooting).

BTW: To see a larger version of the above table, just click anywhere on the table with your mouse. The larger image will appear in the same window. To get back to the Blog, simply click on the "close X" that appears at the upper right hand corner of the larger image. This is true for any of the images on this blog. Thanks!