Grape pomace has become a crucial part of winemaking as more winemakers
and viticulturalists in South Africa come to understand and realise the benefits
that composted grape pomace has for their own vineyards.
In a personal interview with Professor Barbara Wechmar, a retired Microbiologist,
(January, 2010), it was confirmed that corrective composting of grape pomace
results in healthy humus-rich compost, which may be used back in the vineyard.
Wechmar is co-founder of Bioearth, a company specialising in the manufacture
and supply of inoculants for composting and plant food extract. Wechmar’s
primary focus is that of consultant and wine industry clients include Klein
Constantia, Tokara, Thelema and Backsberg.
Composting, as propagated by Wechmar focuses on the enzymatic digestion or
breakdown of organic material through the inclusion of a large and diverse
number of micro-organisms added as inoculants. Natural additives such as clay,
rockdust, ground seaweed kelp, zeolite and organic feedstock’s assist in the
complete breakdown of organic matter.
Stiaan Cloete, viticulturalist at Klein Constantia, confirmed in a personal interview
(February, 2010) that Wechmar’s composting principals and regime had been
introduced at Klein Constantia. Cloete regards corrective composting to be part
of alternative, pro-active farming, in-tune with nature and less reliant on
agrochemicals. According to Cloete, positive changes noted in the past three
years include improved soil structure, reduced erosion and increased water
retention. Also noted was the prolonged ripening of grapes, optimal ripeness of
berries and balanced vineyards with unassisted growing cycles. The biodiversity
of insects and plant life had also quadrupled and mealy bug counts were low,
which according to Cloete, was due to the presence of natural predators.
Next week: constructing a windrow for composting
Source: Waste Management in the South African Wine Industry – Catherine Dillon, 2011