We compost our winery by-product and have created a unique impermeable semi-enclosed compost pad that enables us to create nutrient rich compost which we apply to the soil under our vines throughout the season.
We have taken thousands of tonnes of organic matter out of the vineyards over the years and now we have identified that we need to start the process of replenishing the soil to its original status and what better way than to use beneficial by-product to do this!
From vintage 2016 Giesen began composting 100% of its winery by-product (skins, seeds and MOG). For those who love numbers; 3,500 cubic metres of by-product was converted to 3,500 cubic metres of compost in 2017.
At Giesen we have recently invested in making a compost pad the size of an Olympic swimming pool. It is a semi-enclosed impermeable pad that enables us to create nutritious compost from the by-product of the winemaking process. The pad is tapered and has a leechate collection system where we collect leechate in a tank and reapply it back to the compost when the compost needs wetting. This reapplies nutrition back into the compost.
We are the only winery doing this on this scale, leading with this type of sustainability initiative in Marlborough.
For those who are uncertain as to how compost is made, we use 30% Grape Marc, 30% Browns & 30% greens (bark, wood chips, grass cuttings, tomato plants). We lay the material out like a lasagne and wrap it to make it anaerobic. We inoculate the ingredients with effective microbial solution then material breaks down with heat and mixes together and compost is created, this process takes a period of six months to complete.
Alex Giesen travelled back to Germany to find the right equipment to spread the compost as this has been part of everyday practice for many producers in Europe. The result was three special compost spreader machines which make it easy to spread the compost under the vine or inter-row. We use Langlois under-vine weeder behind our compost spreaders which tills over the earth to mix the compost up with the soil.