Once again the seasons are turning, and Autumn brings its own special rhythms, colours and light. It is a time when Avondale’s ethos “Terra est Vita” – Soil is Life – is top of mind. As our vines get ready for their months of rest, we have plenty of work to do to ensure that our vineyard ecosystem is braced for the rains and that our soils are well-prepared ahead of the next time of growth. Our BioLOGIC® approach demands that we understand the community of life in our soil and apply this knowledge in ecologically wise ways. Avondale has 13 different soil types – from cool, dark loam to decomposed granite and decomposed sandstone; from no rock to 75% rock. This diversity of soil types has literally shaped the way we grow cultivars and make our wines. According to soil type, we planted our vines in particular soil pockets in blocks of around one-hectare. At the end of the growing season all soil pockets have to be sampled and scientifically tested so that we can restore balance.
Balancing the Soils
Unlike conventional farming, the BioLOGIC® approach has a keen focus on the micro-nutrients in the soil. Shortages of minerals such as Zinc, Calcium, Sulphur, Manganese and Magnesium are typical in the Western Cape soils. For vines, there is a significant nutritional benefit offered by these minerals. They support photosynthesis, triggering complex enzyme reactions and playing an important role in building proteins. The fact that we have long nurtured complex communities of life in our soils, with thriving beneficial bacteria, fungi and micro-life, means that we can maintain the nutritional balance of our soils by using natural, elemental sources of these minerals. For instance, we make use of rock phosphate rather than the short-term agricultural version, as the micro-life will break it down and make a sustained release of phosphate available to the vines over time. Thus, we can avoid the ‘spike and crash’ effect of commercial products that cannot sustain life in the soil.
Sowing the Cover Crops
Like the leaves on the vines, last year’s cover crops are returning to the soil, and it is time also to sow the seeds for the new, lush, Winter growth that will prevent leaching and erosion during the rainy season. Ten different mixes of cover crop seeds are prepared to ideally match particular soil pockets. We use a minimum till method with a custom-designed planter to ensure that the seeds are well-planted without breaking the delicate structure of our living soils. When the winter rains come, legumes, grasses and cereals will spring to life and harbour a ‘rainbow nation’ of beneficial fungi and bacteria in the soil, which in turn, will do their work of making minerals available to the vines when Winter is over.