Chardonnay with Iron deficiency
Pinot Noir with Magnesium deficiency
It is essential to analyse the soil and vine tissue to understand the availability of nutrients in the soil. Even though we are organic, and never use herbicides or pesticides, it is sometimes necessary to apply nutrients to the soil and the vines to address any significant deficiencies. Agronomy
is the application of various soil and plant sciences to soil management and crop production. To advise us on such matters we employ the services of John Buchan, an excellent agronomist who specialises in organic viticulture.
John has just analysed the results of some recent soil and tissue samples and it seems that generally the overall results are encouraging. Whilst pH levels, at around 7.8, are still high, they are slightly lower than when we first analysed the soil. pH is a measure of the acidity of the soil and is important as a high pH can "lock up" nutrients restricting their availability to the vines.
It's important to recognise that plant nutrition is a balancing act, as over application of any single nutrient can cause antagonism with other nutrients. Our priorities for this autumn and next spring will be improve the levels of Magnesium, Manganese and Iron, which are still very low.
As can be seen on the examples above, the leaves on some of the vines are already showing signs of these deficiencies.