Soil and nutrients

By Jacqueline Maclaurin

Viticultural Technician, Wither Hills

Sunshine greeted us the middle of November and the temperatures started rising in time for the first field day of the season, a field day focusing on soil. Tim Jenkins, a soil scientist and microbiologist with a wide-ranging background in sustainable agriculture, talked on the techniques used to monitor the soil as part of the Focus Vineyard Project, what these may tell us about the soil, and how organic and conventional management techniques can have positive and negative long term effects on the soil. (See notes from Tim’s talk here.)

This got us thinking on how we can look at ways to change our management of the soil, and going forward what techniques we could employ to reverse any damage we may be doing or to enhance the benefits we may be employing.

Some of these we will be looking at going forward is nitrogen-fixing cover crops such as red clover or vetch to plant post-harvest, and applying lime flour to stimulate soil microbial activity, therefore allowing nitrogen to be more plant-available. We will be closely monitoring the nutrient levels in the blocks following flowering and look to do leaf and petiole tests at veraison.

We will apply Serenade Max to organic Sauvignon Blanc and Switch to the conventional at 80% flowering. The same flowering sprays were applied to the Pinot Noir both organic and conventional, but this had a spray at 5% and 80% flowering. We will continue to watch the growth in all blocks and will likely bunch thin the organic Pinot Noir prior to bunch closure to retain as much canopy as possible but reduce the crop load on the vines.

We will look at broadcast spreading compost in the coming year on the organic blocks.

Organic Sauvignon Blanc, 7 Dec: Some buckwheat manages to flower despite dry weather