PureAg in Viticulture
We specialize in organic and biodynamic products and sell world wide. We have achieved some great results in improving soil biology, diversity and structure, which have lead to healthier vines, and in turn wines with more depth, structure and balance.
Growers never used to think twice about applying hi-analysis NPK fertilizers. The vines responded quickly and plant sap tests indicated the vines were taking up the nutrients. Using synthetic chemicals to control pests, diseases and weeds, was standard practice. Having a neat, tidy, and weed free vineyard was a sign that you were a good manager. Unfortunately, pests and diseases would come back every year, no matter how many chemical applications were applied. Weeds would persist even when pre-emergent and systemic herbicides were sprayed multiple times throughout the year. As we have learned over time, it’s all about getting the biology right at the ground level. Once the soil is improved the plants become healthier
Most vineyards, under conventional management practices, tend to have soils that are high in bacterial numbers, low in active and total beneficial fungus (therefore unable to suppress disease causing fungus), low in flagellates, amoebae and nematodes (this means low nutrient cycling) and slightly high in ciliates (this means soils are on the anaerobic side of the scale). Vineyards which have been managed using natural inputs, and lowered pesticide and herbicide use, tend to have a better fungal to bacterial ratio, and more diverse protozoa and beneficial nematode numbers.
Ideally, good vineyard soils will have between a 3:1 and 5:1 fungus to bacterial ratio but this is rarely the case when vineyards are managed with pesticides, herbicides and hi-analysis NPK fertilizers. These all contribute to decreasing biological diversity, lowering natural disease suppression, increasing soil compaction and salinity levels. A healthy soil should contain 23% water, 25% oxygen, 7% organic matter and 45% minerals. Compacted, unhealthy soil will have about 12% water, 15% oxygen, 3% organic matter and 70% minerals.
A simple on site test, that anyone can do, is to count earthworms in the soil. Digging a hole and counting the worms will give a quick indication of soil health. If numbers are greater than 10 to 15, then soil biology and diversity is alive and kicking, if there is only 1 or 2, then its time to change as something is wrong in the management practices.
Testing sap at flowering will show biologically inoculated vineyard blocks thrive. The vines will have all the nutrients in the ideal range when compared to other conventional blocks, which are generally low in several micro and macro-nutrients. Biologically healthy soil means nutrients are bio-available to the vines with the right amount of nutrient at the right time. A plant is able to control pH around the rhizosphere of the root zone which means it can decide what nutrients are needed and when they are needed to best suport plant function.